The mysterious “Hutchings” filter factor for b/w landscapes

[Heroique]

When using b/w filters for landscapes with important shadows, do you add a “Hutchings” filter factor in addition to your filter’s suggested factor (or alternatively, in addition to your thru-the-filter metering)?

As I understand it, the Hutchings factor (after Gordon Hutchings: see Steve Simmons’ “Using the View Camera”) provides your filtered scene with some additional exposure – in addition to what you’ve already added due to the b/w filter you’re using.

The reason is because shadowed areas typically transmit a higher proportion of blue light, precisely the type of light that yellow, orange and red filters can take away. The Hutchings factor puts it back in.

This additional Hutchings factor can be significant. For example, you start with the filter’s suggested factor (or start with your thru-the-meter reading), and then, in addition:

Add an additional stop of exposure for filters #11 (light yellow-green), #16 (medium orange), and #21 (light red)
Add an additional 2 stops for filters #25 (medium red) and #29 (deep red).
It recommends no additional exposure for yellow or medium yellow filters.

For me, depending on film type and personal tests, this method has indeed saved some of my b/w shadowy landscapes, but at the (often prohibitive) cost of putting highlights at greater risk, requiring some N-1, or N-2, or compensation development.

Please share your ideas or experiences with Hutchings filter factors.

Might they work for you?

[Michael R]

It shouldn’t put highlights at risk, so I wouldn’t worry about that.

Technically the filter factor is meant to compensate for the kinds of things you are talking about under average conditions, so to me the Hutchings factors are kind of like additional “safety factors”.

[Vaughn]

I already factored all that in...especially when I am planning on the shadows dropping. I check my meter, lick my finger & stick it in the air, choose an exposure, and wonder why my finger is wet. I call it the Hutchins Finger of Fate.

[Heroique]

I already factored all that in...especially when I am planning on the shadows dropping.

Curious if you mean just the shadows are dropping, or the values of the entire scene are dropping, including the shadows, like high wispy clouds passing over the sun.

Your moistened Finger of Fate may be a good predictor of breezes! :D

BTW, for those who have a copy of Simmons’ “Using the View Camera,” there’s a good example in his “Steamboat Slough” photo from the Introduction:

Simmons meters the darkest portion of the scene (for which he desires texture) directly through a #16 orange filter. But he says he didn’t add the additional 1-stop Hutchings factor for that filter, since he didn’t know about Hutchings factors at the time. The negative, he says, came out too thin for easy printing. He doesn't mention film type or choice of processing.

[Vaughn]

Its all relative, depending on the filter color, colors present, and the needs of the process I'll be printing with (non-silver). Small shadow areas where I do not need detail, but are 'fogged' by the sky-scattered blue light can be "cleaned up" with an appropriate filter. This can let me print the next lighter values as rich textured blacks, strengthen by the pure black areas.

But I rarely do so -- my use of a yellow filter tends to be more in the fall under the redwoods -- to lighten yellow leaves. Not a whole bunch blue light-filled shadows in the circumstance.

Orange filter on this 5.5x14 from Zion (platinum/palladium work print)

[Drew Wiley]

I NEVER take a reading through a filter. That's voodoo because meters are not spectrally consistent in their sensitivity; nor are films. And even Fred Picker's tweaked spot meter had to be designed around a specific type of pan film, probably Tri-X. What I do is gray card bracketing on smaller more affordable roll film under repesentative lighting conditions (generally outdoors) for each specific film and contrast filter combination, then read the actual developed results with a DENSITOMETER. That's what gives me a true filter factor. It makes a real difference to do it scientifically this way. For example, two allegedly similar films, TMax100 and Delta 100 differ a whole half stop in green sensitivity. The published spectral sensitivity chart gives you a clue this is true, but an actual film test more accurately tells you the filter factor. Other details like hypothetical lens flare, internal bellows flare, mosquitoes flying around inside the bellows, blah blah, can be additionally factored if really necessary, but a decent lens compendium shade solves most of that kind of thing.

[Vaughn]

Your moistened Finger of Fate may be a good predictor of breezes! :D


If the finger get cold, I give the breeze the middle one and wait it out. Actually, decades of photographing in the redwoods where I never have exposures less than several seconds and usually in the minutes range, the hairs on my body detect the slightest whisper of a breeze (perhaps a few of those Bigfoot genes expressing themselves, eh, Drew?).

But it really is not all that difficult. Slap on a filter, apply the factor, expose the film, develop it, go "Oh, shit, next time I'll add another stop with this film under these circumstances." and move on. A badly exposed neg is not going to crash the Mars lander.

[Drew Wiley]

Do those long whiskers really grow just on the north side of your face, Vaughn?

[Doremus Scudder]

It's interesting to me how Drew and I arrive at the same general results through completely different means.

I ALWAYS meter through the filter.

Yes, I'm aware of the different spectral responses of meter and film. I do essentially the same thing as Drew (not as quantifiably though, since I don't have a densitometer), testing to find a read-through compensation for each of my filters and films and my Pentax spot meters (If I had different meters, I'd have to do this for all of them as well - good thing I only use one type of meter). This factor could be thought of as a kind of refinement to the "Hutching's factor." Mine consist of an exposure compensation for each filter and film combination and a development-time compensation if needed (stronger filters often do).

This is not nearly as complicated as it sounds, since it's really only the rather strong filters that need much compensation and I only use a couple of films. Initially, I read the scene through the filter and make several negatives at different exposures. I try to choose a scene that has deep shadows lit by blue skylight for those filters that block blue. I'll then develop these at a few different times, keep good field notes and adjust as needed.

So, for example, with 320Tri-X and a #25 filter, I'll add a stop of exposure and develop -1 to whatever development I normally would. I have factors similar to these for about five different filters. I find I can just read and shoot through a #8 filter, a #12 filter needs a bit of added exposure, etc., etc.

Still, my method isn't perfect. However, despite the uncertainties of metering through filters, it's really the only way to have any quantifiable idea of how the filter will affect adjacent tones in the scene, e.g., green trees against a blue sky. One can guess that a green filter would darken the sky and lighten the trees, but often just slapping on the green filter results in a homogeneous merger of tones. I can meter sky and trees through different filters and pick the one that gives me the most separation.

It seems futile to me to go through the Zone System visualization process of measuring values and placing them and choosing a development scheme and then just adding a filter to the mix without any idea (except past experience) as to how all those placements are going to be affected. Reading through the meter gives me some idea, however imprecise, and the compensation factors I generate even out much of the variance that would otherwise be present.

Still, using filters introduces an uncertainty factor that we just have to live with, no matter what kind of methods we develop to compensate. When in doubt, err on the side of overexposure and bracket. Knowing your materials and their responses cuts down on the doubt.

Best,

Doremus

[Drew Wiley]

I use a lot of different contrast filters as well as different films, and seldom have a rude surprise. My personal filter factors work perfectly nearly all the time. The exception would be on those rare occasions when I happen to be experimenting with either an unfamiliar film or an off-brand EU film with less than ideal batch to batch quality control, or else when I'm out casually snapshooting with the Nikon and get too lazy to meter every single shot (I only trust the Pentax spotmeter, not TTL metering). But regardless of the specific methodology in play to obtain consistent results, there is simply no substitute for a lot of actual experience over a variety of relevant conditions. The kind of natural softbox light we get here on the coast when fog is active is an entirely different scenario than deep shade tonality issues under open sun once the fog moves out, or especially versus high altitude contrast scenarios. It's all fun, part of the overall challenge.

I put the Zone System in the rear view mirror a long time ago. It's a nice communication tool to have somewhere in storage, but inevitably becomes its own ideological trap after awhile, just like an oversized bear trap used to snag Bigfoot hides for sake of log cabin floor rugs.

[Heroique]

…Meters are not spectrally consistent in their sensitivity; nor are films. Two allegedly similar films, TMax100 and Delta 100 differ a whole half stop in green sensitivity. The published spectral sensitivity chart gives you a clue this is true, but an actual film test more accurately tells you the filter factor.

Nice information from the field – do your film tests indicate a half-stop difference with other colors, or is green your most extreme example? And do other b/w films, in addition to Tmax100 and Delta 100, show this degree of variability?

I’m also curious if your various meters differ by this amount. Talk about complications!


Still, using filters introduces an uncertainty factor that we just have to live with, no matter what kind of methods we develop to compensate.

One might say b/w filters are “more art than a science” – or an art with plenty of field and darkroom notes plus personal testing. ;)

[Drew Wiley]

All my Pentax spotmeters are calibrated to not only match each other, but a tightly defined industry standard. I even have shades for them. The fact is, panchromatic films differ somewhat from one another. Once you start using very deep contrast filters, these film differences become more prominent. A deep 29 filter needs just 3 stops of offset with Bergger 200, for example, but will require 3-1/2 or four with most pan films, for which a gentler 25 red makes more sense. Orthopan Acros can't deal with a deep 29 red at all without emptying the shadows, while an extended red film like old Tech Pan, or near-infrared films, will have opened up shadows. Another example would be how Pan films react to deep blue filters in different degrees. Reduced green sensitivity itself might have once be regarded as an asset for inspection development, but becomes a penalty to a more natural look, where the amount of green sensitivity has been raised somewhat in TMax films. This is apparent even with respect to light yellow-green filters. There's nothing complicated about it. You just have to test and learn one film at a time. Having a choice of films is a good thing. The specific manufacturer technical data sheets already provide you with recommended filter factor starting points, which are generally close enough for real world photography. No need to guess!

[Daniel Casper Lohenstein]

Perhaps the filter topic is inexhaustible. I need to write it down here on the forum so I can think it through logically. If we want to get a reasonable grip on the problem, we can probably only use strict measures, not ad hoc decisions.

This includes restricting the use of a specific film material from a specific manufacturer, the use of the same filters from the same manufacturer, and the consistent maintenance of a defined procedure.

An example: with my Nikons, EV corrections for TTL metering differ from the specifications given by the filter manufacturer, B+W. For a wonderful 023 dark yellow filter I get -0.6 EV (x1.5) with the camera, while B+W specifies -1.6 EV (x3). So the images are theoretically underexposed by 1 EV. In practice it is exactly this: the images are underexposed. This is less noticeable in the highlights, which are still in the printable range when underexposed. But the shadows are too dark. The filter is intended to improve the shadow drawing in the landscape ... My own tests with Ilford film in HC110 H showed that the B+W value of -1.6 EV is correct and therefore I need +1.6 EV more exposure.

But only with Ilford and HC110 H. With Kodak, Foma, Fuji, Agfa (Kentmere), Rollei it looks different. Crap, such a bad luck. Because the film emulsions react differently. Now I can test my way to Persia. - No, I'll stay with Ilford. And if I want less grain, more sharpness, higher resolution, I take 6x6 or 4x5.

But I have got larger lenses, a wonderful Symmar S MC 5.6/210. So I need bigger filters. Now, instead of buying the right BW filter for each lens - an expensive affair - I use the Cokin P system for 6x6 and 4x5. Yes, I know, other manufacturers are better. But only Cokin has the P size, which is compact and in which there is the very good, very inexpensive, highly adjustable SRB Elite bellows lens hood, which works very well in the large format context.

Cokin also gives filter factors and correction values for this filter system. I have had good results with the correction for the yellow filter, +0.6 EV (x1.5) and the red filter +3 EV (x8). The images are sufficiently dense in the shadows. I have not used the other filters since. Anyway, I now only use BW screw-in filters for the Nikons, on which I set an ISO correction of -1 EV and meter an additional loss of light of -0.6 EV with TTL, and Cokin P filters for the larger cameras, for which I set +0.6 EV on the external light meter so that +0.6 EV adds to the exposure. If I took the B+W 023 yellow screw-in filter for 4x5, I would set +1.6 EV (x3) on the exposure meter. And I limit myself to Ilford films. If you want more, you have to test more. Otherwise it's all inexhaustible guesswork.

[Drew Wiley]

All that fuss just to add yet another set of variables of uncoated filters and TTL meterings? How come I get entirely predictable results time after time, year after year, using different camera formats, different film manufacturers, different film developers, obviously many different lenses, a wide range of lighting circumstances? No guesswork involved. Filter factors aren't rocket science. No need to invent another Mars rover. A minor twist the correct amount on the scale of the spotmeter tells you everything you need.

[Michael R]

How come I get entirely predictable results time after time, year after year, using different camera formats, different film manufacturers, different film developers, obviously many different lenses, a wide range of lighting circumstances?

Because you don’t. :) Nobody does.

[Heroique]

An example: with my Nikons, EV corrections for TTL metering differ from the specifications given by the filter manufacturer, B+W. For a wonderful 023 dark yellow filter I get -0.6 EV (x1.5) with the camera, while B+W specifies -1.6 EV (x3). So the images are theoretically underexposed by 1 EV. In practice it is exactly this: the images are underexposed. This is less noticeable in the highlights, which are still in the printable range when underexposed. But the shadows are too dark. The filter is intended to improve the shadow drawing in the landscape ... My own tests with Ilford film in HC110 H showed that the B+W value of -1.6 EV is correct and therefore I need [+1 EV additional] exposure.

This experience caught my attention because Ilford + HC110 H is a favorite combination with my Nikon 35mm cameras – F100, FM3a, N90s, and EM. So I’m naturally curious which cameras are giving you this TTL -1 EV underexposure?

Also, does it happen with all your b/w filters, or just the 023 yellow?

I’m not sure by your description, but are you saying the 023 reduces highlight values less than it reduces the shadow values? If so, this may very well be the “more-blue-light-in-the-shadows” phenomenon which the Hutchings factor tries to remedy.

[Drew Wiley]

I absolutely do get consistent totally predictable results, Michael, just as long as it's a quality control film like Kodak, Ilford, or Fuji. I can't speak for emulsions poured out of the Bubba Gump shrimp gumbo kettle. And not if I trusted TTL metering! - too many unrelated internal variables. Once I started using true spot meters over forty years ago, I never looked back. Just today I was doing some practice with my Nikon FM2n, and just for fun comparing the kind of exposure assessment it would give me, versus the handheld Pentax spotmeter itself. Of course, I already knew the answer. Not everything in the world is a giant gray card; and besides, I want to know where small deep shadows land on the scale, and bright highlights too - not just an averaged stew!

But if the issue of filter factors gets confused with just plain not understanding how a particular film curve is going to behave under a set of exposure and development circumstances, and how it will print, well, then it's best to learn those skills first, before applying a filter. Films can sometimes behave like chameleons in relation to very long exposures and strong contrast filters. But that can be tested for too, and predictable filter factors determined, if someone happens to do that kind of work.

As far as more blue in the shadows under an open blue sky ... duuuh .... I'm a color photographer too.

[Daniel Casper Lohenstein]

This experience caught my attention because Ilford + HC110 H is a favorite combination with my Nikon 35mm cameras – F100, FM3a, N90s, and EM. So I’m naturally curious which cameras are giving you this TTL -1 EV underexposure?

Also, does it happen with all your b/w filters, or just the 023 yellow?

I’m not sure by your description, but are you saying the 023 reduces highlight values less than it reduces the shadow values? If so, this may very well be the “more-blue-light-in-the-shadows” phenomenon which the Hutchings factor tries to remedy.

Why so complicated? Imagine the zone system scale. If the structured shadows are in III and the structured highlights are in VII, then at -1 EV underexposure the shadows fall in II and the highlights in VI. The structured shadows are no longer in the printable range from III to VII. They turn black on paper. The highlights still remain in the printable range. They are darker, but still in VI. You might not notice anything if the darkest shadows are only in IV and the highlights are in VII, but with higher contrast scenes you get problems. You might not notice anything if the darkest shadows are only in IV and the highlights are in VII, but with higher contrast scenes you get problems. Especially with short focal lengths, i.e. a lot of sky and many objects in the image field. If you use long focal lengths to clean up the image, to eliminate background or sky areas, you tend to work with little contrast. Perhaps Bruce Barnbaum's placing shadows in IV is a reminescence to this problem, as a result of using filters in every exposure.

The F100 is a very good camera with a useful light balance in third stop resolution. It has been every Nikon I have used so far. For a while I thought I had to have one camera each for color and black and white, and because Nikon cameras are so good, another backup. So I used the F2, F3, FM2n, F100, F4, F5. With each camera I achieved a TTL measured reduction of -0.6 EV with B+W 023. But the manufacturer says x3, so -1.6 EV, which is why I should actually expose +1.6 EV. I set that on the exposure meter, and the negatives turned out much nicer than the pictures with the Nikon TTL. Sure, it could have been a lazy shutter on the large format camera. But the pictures become better with every lens, with every light meter, and, what really convinced me then, when I started using a Sekonic incident light meter to do macros with the Micro-Nikkor 3.5/55 (with additional macro prolongation faktor): also with the Nikons. That is why I always set +1 EV on the light meter with 023 filters, 64 instead of 125 ASA for HP5+ in HC110 H, 16 instead of 32 for FP4+ in HC110 H. The remaining +0.6 EV is done by the Nikon.

But these are all subjective values, from comparison with unfiltered Nikon shots, which also all came much denser in the shadows than the filtered shots. I'd have to put in the Stouffer card sometime. But as Drew Wiley already indicated: you can also test yourself into madness.

[Heroique]

Imagine the zone system scale...

That’s a nice analysis of your metering experience, a great testament to personal testing in field and darkroom.

However, I was asking if your meter might have reduced highlights less than they reduce the shadows, due to the higher proportion of blue light in the shadows, and the filter’s removing more of this part of the total spectrum than other colors. That is, a non-linear change. (The type of change, Simmons says, that the Hutchings factor specifically means to help.) It sounds like you haven't run into this phenomenon.

I've seen this happen at very high altitudes in my region on sunny days, about 1/2 or 2/3 stop, and more noticeable the more complete the shadow is.

[Daniel Casper Lohenstein]

That’s a nice analysis of your metering experience, a great testament to personal testing in field and darkroom.

However, I was asking if your meter might have reduced highlights less than they reduce the shadows, due to the higher proportion of blue light in the shadows, and the filter’s removing more of this part of the total spectrum than other colors. That is, a non-linear change. (The type of change, Simmons says, that the Hutchings factor specifically means to help.) It sounds like you haven't run into this phenomenon.

I've seen this happen at very high altitudes in my region on sunny days, about 1/2 or 2/3 stop, and more noticeable the more complete the shadow is.

Oh, sorry if my statement was unclear. We Germans tend to yak other people to death with big and extensive statements about any of our motives for doing anything ....

I assumed that blue is made darker by a yellow filter, while yellow is lightened. So yellow filter darkend blue shadows would have to be considered even darker in the exposure than the metered shadows in a measurement. Which should cause the exposure meter to expose more, if they were mesured through the filter glass. My TTL Nikon does the opposite. Perhaps because yellow is made brighter? Which causes the light meter to expose less?

The Hutchings problem is another issue. As you have presented it, it would say metrologically that a yellow filter changes the color brightnesses in different ratios, non-linearly. That is, the light meter's response to blue is less than to yellow. Therefore, the darkness of the blue is not sufficiently compensated. Which leads to underexposure. Sure, the blues vary anyway, as do the yellows. Especially in the mountains, as you say. Depending on the time of day, weather conditions, etc. But I don't know wether Hutchings or you meant this.

If I understood Simmons correctly, who doesn't report that much on him, Hutchings was concerned with the problem of shadows, which he tries to save by exposing more abundantly - but what becomes of the highlights? - Simmons wrote that Hutchings was concerned with yellow, orange and red filters, not with green filters, which lighten blue, and not blue filters, which lighten blue a lot. They are his personal filter factors for his personal process, with which he photographs the sceneries typical for him at times of day that are typic for him. Like Drew Wiley, see above, who seems to have a photographic process and practice clarified over long years, where things just come out well, while we are still in the process of learning and understanding.

- Simmons said: it's best to measure through the filter, then you'd have shadows and highlights in the ratio or relation that the filter sees them. Absolute values are not yet obtained, only contrast ranges of the sceneries. Then you still have to decide absolutely how much light this contrast scale should receive, so that the contrast scale falls within the desired range, e.g. between III and VII. To do this, one could also measure the given contrast scale without a filter. One would then have to extend the exposure value found without filter by a certain factor, e.g. the filter factor, as a starting point. This is what Simmons suggests, p. 28. "Take your light readings through the filter by holding it in front of the exposure meter." Be aware that this only affects the contrast relation, not the absolute exposure value, which must be adjusted with the filter factor.

I think it gets complicated when you do a relative contrast measurement with the yellow filter, and an absolute measurement without the filter, then do a prolongation of exposure with the filter factor, and add a 1/4 Hutchings obulus to that for the darkened blue. I wouldn't be able to reproduce that so accurately with my process anymore ...

Why don't you take some comparison shots with 35mm film and see which you like better in the end. I took pictures this morning without a filter, because the darker yellow also kills some of the haze in the morning. Without haze, the image lacks depth. Yellow filter images are often more brilliant, but less atmospheric. Especially in the mountains. A filter turns them into abstract and flat patterns, while without the filter they develop air and aerial perspective. Why give up atmospheric haze just for those stupid clouds? https://flickr.com/photos/miloniro/22846477109/in/album-72157658837001681/ Here's an image from a photographer that would be lost with a yellow filter and even with panchromatic film.

Ansel Adams: Natural Light Photography - this book describes filters very extensively.

[Drew Wiley]

Daniel - Barnbaums's habit of placing shadow values atop the barn roof is about as counterproductive advice as I can think of. Where do you go from there? You've already taken up nearly half your straight line already. And that means that there's very little forgiveness at the upper end, and the only solution to a printable negative is gross minus development - the Zone System beaten half to death. Why even bother to meter to begin with if you have to fudge three stops of guess insurance? Playing it safe with a stop of so of extra exposure might make sense when in doubt, but Zone IV ?????? Ridiculous!!!!

I personally like to get the threshold of shadows values above the toe a bit, and find that most Pan films need more exposure than box speed to do that. For example, I rate FP4 at 50. Only with TMax films do I find advertised film speed to work best. But all this is specific-development dependent, so another wrinkle that needs to be ironed out through personal testing.

I also strongly disagree with metering through filters. Just look at the nm spectral sensitivity distribution for various meters. It's never a flat even line, but biassed. Testing for filter factors is easy. Just take the individual filters in question and do a bracket test with 35mm film aimed at a gray card in what you consider typical lighting. Use the factory tech sheet filter factors as a starting mid-point. Make sure your lens and the meter itself aren't aimed toward the sun and affected by flare. Filters do sometimes differ a little from batch to batch even from the same manufacturer, so do test exactly the filter you have in mind for your own kit. And of course, take a reference exposure without any filter at all.

Comparing frames visually over a lightbox is probably adequate for most black and white purposes, though a densitometer reading will be more accurate. An old fashioned trick to make "visual densitometry" more accurate is to take a matte black thin piece of cardboard and paper punch, and punch two hole in the middle of it about two inches apart. Tape your reference exposure (no filter) to the light box and view it through one hole, and leave the other hole for slipping in your respective filter exposures with their bracketed filter factors. If your eyes are rested when you begin, relatively minor differences in density can be detected in this manner.

Personal preferences and the aesthetic application of filters is another topic entirely.

[Heroique]

Simmons wrote that Hutchings was concerned with yellow, orange and red filters.

Here’s a landscape whose sky I wanted to darken with an orange filter. These are the N. Cascades in Washington state at very high altitude under intense blue skies – which offered me a b/w filter non-linear metering experience. ;^)

213245

Tachi 4x5
Fuji A 240mm/9 (w/ orange filter)
Neutral camera w/ 35mm front rise
Ilford FP4+ (in D-76)
Epson 4990/Epson Scan

--Without filter, the sunny cliff (middle tones) were 12 ev, and the shadowy cliff was 11 ev.
--With filter, the sunny tones dropped 1 stop (to 11 ev), but the shadowy cliff dropped 1.6 stops (to 9.3 ev). I remember this being a bit baffling. BTW, I was using my Pentax digital.

After attaching the filter, I placed 11 ev on zone 5, so the shadow detail is preserved, somewhere in the middle of zone 3. The foreground shadows under the Larch trees, however, were mostly lost, but the highest values of the cliff were just captured. I didn’t know about Hutchings at the time, but I don’t think I needed his helpful factors for this shot.

[Vaughn]

...
I assumed that blue is made darker by a yellow filter, while yellow is lightened...
I prefer to think of it as a filter reduces the light coming into the lens, but with specific wavelengths blocked more than others. THEN I start thinking about which wavelengths (colors). So a yellow filter does not lighten yellow (does not add yellow light to the scene)...it just blocks the other colors more relative to yellow, but especially blocks its opposite (blue). I use a yellow filter for fall colors -- it reduces the exposure of all the other colors relative to the yellow leaves (so I give it an extra stop or two to bring all the other colors up to normal exposure levels, with yellows rising along with them.)

All much of a muchness, but I just prefer to use language that matches what is happening. It helps me to understand what is going on when it comes time to apply it.

YMMD

[Drew Wiley]

Bingo! Although I had already been doing high-altitude LF color photography for about a decade, my first "school of hard knocks" experience with black and white film and contrast filters was in the Enchantment Range of the N. Cascades - which are not in fact really that high compared to the high Sierra I was accustomed to. I was in good shape back then, and made it clear up the 6000 ft of goat grade to Dragontail Glacier (now totally gone due to global warming), and even a bit onto the spiky "tail" of Dragontail Peak itself. The moon was rising just above its sharp summit in a deep blue sky. I had my Sinar 4X5, the early version of TMax 100 film, and exactly one contrast filter - a deep red 29. I applied the correct filter factor, but didn't yet appreciate the additional effect of blue in the shadows themselves. The resultant print is dramatic and effective, but a bit too dramatic or Ansel-ish for my own taste. Lesson learned. That 29 filter later came in handy with Bergger 200 8x10 film shots, which really digs way down there into the shadows. But for most other applications, a gentler pair of options consisting of a 25 red and 22 deep orange became part of my routine kit instead, along with a medium-dark green filter.

[Michael R]

In my opinion part of the reason a lot of people misunderstand filtration is because of the bad wording in a lot of books/explanations that seems to imply that a filter lightens like colors. Obviously a filter does not add any light. It can only attenuate light. I think it would help beginners if teachers said a colored filter passes its own color and blocks other colors, as a starting point. It is the addition of extra exposure indicated by the filter factor which ends up boosting like colors.








I prefer to think of it as a filter reduces the light coming into the lens, but with specific wavelengths blocked more than others. THEN I start thinking about which wavelengths (colors). So a yellow filter does not lighten yellow (does not add yellow light to the scene)...it just blocks the other colors more relative to yellow, but especially blocks its opposite (blue). I use a yellow filter for fall colors -- it reduces the exposure of all the other colors relative to the yellow leaves (so I give it an extra stop or two to bring all the other colors up to normal exposure levels, with yellows rising along with them.)

All much of a muchness, but I just prefer to use language that matches what is happening. It helps me to understand what is going on when it comes time to apply it.

YMMD

[Drew Wiley]

Well expressed, Michael, speaking from the film's own perspective. I think AA confused a lot of people in that respect in his how-to books, overcomplicated the concept. Any added filter decreases the density of opposite hues in the film itself. What transpires during printing is the opposite - after all, it's a negative process!

[Daniel Casper Lohenstein]

Daniel - Barnbaums's habit of placing shadow values atop the barn roof is about as counterproductive advice as I can think of.

That's exactly what I think. Also concerning the rest of your explanations. - Besides, this was not invented by Barnbaum, but by Adams, as effective ISO instead of nominal ISO.

[Doremus Scudder]

Daniel,

I think you're making things too complicated. If you find that using a certain filter with your in-camera meter consistently results in under- (or over-) exposure, just make a note of that and add that exposure back using the exposure compensation when you use the filter. Basically, that's what I do with all my filters.

It seems silly to not meter through the filter when using a 35mm SLR camera with a sophisticated TTL meter. Sure, you can take readings and then set the exposure manually, applying the filter factor, but that kind of defeats the whole idea of small-camera photography in my view.

FWIW, my approach to metering and exposure is very different with a small camera with a built-in meter than when shooting LF using a hand-held spot meter.

With the latter, I read shadows and base my exposure on that (and read highlights and base my development on that). But, with a built-in meter, I just use the average reading as a starting point and then adjust that with exposure compensation for contrasty situations and for filters that don't give me what I want at the basic setting. It seems to me that you could do that as well.

Keep in mind that, unless you're just shooting grey cards under controlled lighting, there will be a lot of variables when using colored contrast filters that make it difficult to exactly predict what the result will be. We've mentioned differences in the spectral responses of eye, film and meter. Add to that the color temperature of the lighting, uneven-colored lighting (e.g., shadows lit by blue skylight while the rest of the scene is lit by sunlight), and the distribution of colors in the scene. This latter can really effect your meter reading if you take an average reading through the filter. Imagine using a yellow filter in a scene that is largely yellow leaves lit by warm light from a sunset. The light passing through the filter will be almost the same intensity as using no filter at all. Contrast that with a scene with lots of blue sky and deep shadows lit by blue skylight; the amount of light blocked by the filter will be significantly more than in the first case. This is why blindly applying filter factors doesn't work so well; it will obviously give different results with the same basic unfiltered meter reading. Additionally, however, if you're reading through the filter, and your meter is less sensitive to blue than to yellow, you're going to get overexposure in the first case and underexposure in the second.

The only way we can deal with this is to recognize and compensate. Testing is good, but you don't have to go overboard. It seems to me you have enough data to add the correct exposure compensation(s) to your filter(s) to get the results you want.

Best,

Doremus

[Daniel Casper Lohenstein]

Tachi 4x5
Fuji A 240mm/9 (w/ orange filter)
Neutral camera w/ 35mm front rise
Ilford FP4+ (in D-76)


Very handy and nice combination!




--Without filter, the sunny cliff (middle tones) were 12 ev, and the shadowy cliff was 11 ev.
--With filter, the sunny tones dropped 1 stop (to 11 ev), but the shadowy cliff dropped 1.6 stops (to 9.3 ev). I remember this being a bit baffling. BTW, I was using my Pentax digital.

After attaching the filter, I placed 11 ev on zone 5, so the shadow detail is preserved, somewhere in the middle of zone 3. The foreground shadows under the Larch trees, however, were mostly lost, but the highest values of the cliff were just captured. I didn’t know about Hutchings at the time, but I don’t think I needed his helpful factors for this shot.

So, here we go! +1.6 EV is your filter factor. The shadows will be good then. As for the highlights, you will have to develop a bit shorter. N-0.5, so about 10% - but only if the structured highlights are too bright, what is not the case here. If they are brighter than VII, you probably will develop even shorter anyway, with this kind of subjects.

[Daniel Casper Lohenstein]

Daniel,

I think you're making things too complicated.


Of course, this is all very complicated. You're right! I just wanted to think logically through the matter.

If you use a 35 mm camera, you are only marginally interested in the zone system. That's why I only set the exposure meter to 64 instead of 125 ISO with HP5+ and the 023 filter, and the TTL metering does the rest.

If I use a filter at all. I think the beautiful mountain landscape above would also be interesting without a filter. You would have a gradation from the trees to the rocks to the sky when using a blue filter. Perhaps the rocks would have atmospheric haze and perhaps look more immense. While in the trees there would be more enveloping light instead of relief. It would simply be different images.

I don't even compare contrast ratios with and without the filter. That is too much for me. I use the filter factors I've had good experience with and keep the structured highlights just under VII. I use HC110 H with moderate movement, which balances and also exhausts in the highlights. Actually, I realize with 9'00'' a N-0.5 development, that tells me my last test that I made once some time ago.

I also think that it is possible to worry too much. But: if someone is interested in it, you can get into the matter. That's what the forum is for.

Tschau zäme

[Michael R]

On a related note I'd add that the misconceptions many people have regarding how camera filters work extends into the darkroom when it comes how VC filters work. It just isn't well taught or explained in my opinion.


Well expressed, Michael, speaking from the film's own perspective. I think AA confused a lot of people in that respect in his how-to books, overcomplicated the concept. Any added filter decreases the density of opposite hues in the film itself. What transpires during printing is the opposite - after all, it's a negative process!

[Heroique]

I was in good shape back then, and made it clear up the 6000 ft of goat grade to Dragontail Glacier …I applied the correct filter factor, but didn't yet appreciate the additional effect of blue in the shadows.

Yes, I too was in the heavens for the cliff scene (above) where the blue light baffled my Pentax digital and me. This blue light surprise might have been even greater – say a 1-stop or 1.3-stop differential drop – had the shadows not been partially illuminated by reflected light from the nearby sunny rocks.

[Bernice Loui]

Might not apply, still..

Idea-suggestion, avoid contrast altering color filters for B&W if and when possible. Scene tonal-contrast altering color filters for B&W are often used to deal with a blank sky or enhance-hold back specific tonal-contrast rendition of colored objects on B&W film. While selective contrast-tonality enhancement via manipulating how colors would be rendered on B&W film can add drama and interest to the image, selective color filters tend to affect how the image is rendered on film overall.

Another way to reduce the use of color filters for B&W would be to work with light, composition and all related in place of applying color B&W filters.



Bernice

[Drew Wiley]

Huh? That kind of logic is like stating that if you never drive your car out of its garage, you're less likely to get in an accident. True; but then what's the point of owning a car? Film doesn't see values the same as we do anyway, especially when black and white film is involved. And contrast filters can be selected for subtle tweaks as well as dramatic shifts if desired.

[Vaughn]

Bernice, the film and lens already alters how colors and tonalities are reproduced. Why forsake one tool for another? Consider the use of them all for every image. It just happens that the choice can often be not to use a particular tool.

[Bernice Loui]

Yep, once the image is rendered into B&W, all has been alerted. Question become how has it been altered and there is more than one method to get there.

Color B&W filters are indeed image making tools. IMO, they need to be applied sparingly and properly if at all. What has happened, over the decades of doing this B&W stuff, I've come to dis-like what color filters do the the overall image... again, this is an opinion-preference. That said, still have all those color filters in Sinar 103mm glass, 75mm square and a full set of Tiffen series 9 with all the associated holders-adapters. They sit lots these days.

The filters that DO get used, neutral density and polarizer remain the most often used.


Bernice

[Daniel Casper Lohenstein]

Huh? That kind of logic is like stating that if you never drive your car out of its garage, you're less likely to get in an accident. True; but then what's the point of owning a car? Film doesn't see values the same as we do anyway, especially when black and white film is involved. And contrast filters can be selected for subtle tweaks as well as dramatic shifts if desired.

You see clouds, you see sky, you think: the clouds must be visible, besides that gives the picture drama and depth. And last but not least, the sharpness impression increases, because apparently the haze is removed.

Actually, this is a scheme. We often don't think about it. I read in some books that with panchromatic film you should leave the middle yellow filter on the lens. So that a natural tonal value impression is created. - But you're actually depriving yourself of the possibilities that black-and-white photography offers. Because the yellow filter only creates a certain look. In contrast to this no one would think of leaving a blue filter on the camera permanently. Besides, an XO filter would be better than a Y2 anyway.

So it's not a matter of leaving the car in the garage, but of driving off with your car wherever you want, instead of steering only in a certain direction from the start, which is predetermined from the start with a yellow-orange-red filter. I really recommend Ansel Adams' "Natural Light Photography" again, my copy is from 1952, S. 36ff. The way Adams presents it, it was a revelation for him to depict mountains with blue filters, because that way he could work with the light illuminating the object being photographed. At that time, 1952, the use or the omission of filters was for him an important aspect of visualization.

He writes, p. 37: "If you are photographing a typical landscape ... your first impulse might be to apply a red filter 'to bring out the clouds.' You should first ask yourself what the mood of the scene is, and what you wish the resultant mood of the print to be ... a high contrast effect ... may not in any way relate to the desired mood" - if you see black and white images today, they all have the same contrast, the same basic framework of black and white, between which the gray tones are supposed to make a dramatic impression, Barnbaum-like.

I think we should think about that a little more often. Not using filters unless it's really necessary leads to shorter exposure times, less Schwarzschild effect, less calculating - and more awareness of light as the substance between us and the world we see. - You can also achieve higher contrast with longer development times.

[Drew Wiley]

Huh ?????? Like there's only one cookbook in the world, and we're all obligated by contract to follow it like mindless lemmings? Nonsense. Ansel did what he wanted to do, I'll do what suits my own vision. But I never ever saw an AA print that looked like he used a blue filter. I do keep a deep blue 47 in my kit; I almost never carry a yellow one. Every scene is different. And what filters do is not synonymous with how development alters contrast - two entirely different tool sets. It's also an utter myth that everyone's work looks the same, contrast-wise. There is tremendous variety out there, and even within my own portfolios.

[Doremus Scudder]

Leaving aside the discussion on personal choices and observations...

The point about using filters other than the more common yellow-orange-red family is a good one.

AA liked and used a Wratten #44 filter to approximate the look of orthochromatic film (an image of his of a white house with wisteria draped over the entrance springs to mind - wonderful tonalities). I carry #44 and 80A/B filters with me all the time and find them useful in lots of situations. A #47 will render the blue-sensitive look.

Recently, I've been watching the Ken Burns docuseries on the National Parks. It is full of images made on blue-sensitive and orthochromatic film. I find the tonalities in many of these older images, especially the open shadows, extremely expressive.

There is a "panchromatic look" that we sometimes accept, consciously or unconsciously; deeper shadows, dramatic clouds, etc. That's just fine, but it's just one of the many things we can do with modern panchromatic films and filters. It's nice to have lots of tools in the toolbox.

Doremus

[Drew Wiley]

They do a lot of work to clean up those old images for sake of those wonderful Ken Burns documentaries. I have a friend who does the same thing for use in his books about local history. But the first generations of great landscape photographers had no choice except to use blue-sensitive films. Panchromatic films give us all kinds of options.

[Heroique]

AA liked and used a Wratten #44 filter to approximate the look of orthochromatic film (an image of his of a white house with wisteria draped over the entrance springs to mind - wonderful tonalities).

Here’s the image from AA’s “The Negative” (see chapter two):

213344

Mrs. Sigmund Stern, Atherton, California (c. 1927)

It’s taken with an orthochromatic glass plate, but I imagine a modern panchromatic film with a blue filter would have looked somewhat similar. The sky is lost (in a good way), and the blue-filled shadows are lovely. No Hutchings factor necessary.

Maybe AA asked Mrs. Stern to avoid looking directly at the camera because she had blue eyes. ;^)

[Drew Wiley]

Hard to say exactly what the sensitivity of those old plates was. Current Ortho Litho film seems about three times more sensitive to blue than green. I don't know about Ilford's
Ortho sheet film - haven't tried it. Blue filters will not produce a true Ortho look, at least deep blue, because that would be minus green as well as minus red. A medium green would be closer, or a lighter blue tungsten conversion filter, which I sometimes carry for that very purpose - enhanced atmospheric effect. Ortho renders foliage more buoyantly than pan film, and orthopan like Fuji Acros somewhat that direction too. Ortho films were once popular for studio portraits of men, to make them look more rugged. Outdoors, there are often misconceptions because people think green foliage is truly green, whereas it actually reflects a lot of orange, red, and infrared light. Just look what happens in autumn when leaves lose their chlorophyll - the remaining yellow, orange, and red pigmentation becomes apparent. That's why a deep blue filter will darken most visually green foliage more than even a deep red filter. Lots of fun stuff. Now if I could just find a color sheet film that responds well to fluorescent algae and lichens ....

[Doremus Scudder]

The filter of choice for orthochromatic rendering with panchromatic film is the Wratten #44 or #44a (minus red filter). It may end up passing more green than older ortho film/plates were sensitive to, but works really well. The next best thing, in my experience, is a good old 80A or 80B color conversion filter. These appear blue, but pass a fair amount of green too. I always have one or the other with me.

For the blue-sensitive-only look, a #47 is your friend.

Doremus