75mm lens vignetting

[sergiofigliolia]

Hi all,
I own a Schneider Super Angulon 75mm f/5.6 which I use on my 4x5 camera.
Only lately I started photographing also in colour and noticed quite a bit of vignetting at f/22.
Can anyone suggest an alternative lens which shows less of it?
Honestly if I am to buy a center filter costing like a second hand lens I'd just buy another lens and get rid of this one...

How do the following perform to this respect?
Nikkor SW 75 f/4.5
Fuji Fujinon SWD 75 f/5.6
Rodenstock Grandagon N 75 f/4.5
Rodenstock Grandagon N 75 f/6.8
Schneider Super-Symmar XL 80 f.4.5

[neil poulsen]

Was there a reason that you didn't include the Schneider 72mm Super Angulon XL? It has the largest image circle of all the lenses that you included. While I've not used one, I believe that the center-filter has more to do with the focal length, versus the particular lens.

Take a look at the following two sites for lens comparisons:

LF Page:

http://www.largeformatphotography.info/lenses/LF4x5in.html

Ebony Camera Page:

http://www.ebonycamera.com/articles/lenses.html

The latter gives flange focal lengths, which can be helpful. That's the distance from rear of the shutter to the ground glass, when the lens is focused at infinity. Put another way, it's the minimum distance between the rear of the shutter and the ground glass for any image to be in focus on the ground glass.

[sergiofigliolia]

Was there a reason that you didn't include the Schneider 72mm Super Angulon XL?

The reason I excluded the 72 XL is it is huge and heavy.

[Emmanuel BIGLER]

Hi Sergio

Used for the 4"x5" format, all 75 mm lenses exhibit some natural vignetting. There is not much to do about that except adding a center filter to compensate. Or doing some digital post-processing of course.

I recommend to read this recent article by Dan Fromm, who makes a comprehensive inventory of center filters, you'll find there what you need.

http://www.galerie-photo.com/center-filters-for-large-format-lenses.html

Wide-angle lenses used for reflex cameras exhibit less natural vignetting , due to their assymetrical retrofocus design.
This is a reason why, in 35-mm and medium format, people using reflex cameras hardly ever use center filter with their WA lenses.

[xkaes]

Much depended on what you mean by "vignetting". Are you talking about #1 -- "light fall-off" (the edges of the negative gradually get lighter), #2 -- "resolution drop-off" (clarity decreases toward the edges of the film), or #3 -- "light cut-off" (the edges of the negative quickly get lighter)?

167604

I'm not familiar with your lens, but I assume it is similar to my Fujinon SWD 75mm f5.6. I know my lens has a wide enough image circle to cover 4x5 film, and I assume all lenses in this focal length range suffer from #1 & #2. There are different ways to minimize #1. #2 can be modified somewhat by f-stop selection. #3 would be due to problems with using the wrong shutter, too many filters, rings, etc.

The more details you can provide, the more details we can provide.

[sergiofigliolia]

Much depended on what you mean by "vignetting".

I refer to light fall-off so #1.
I shoot at f/22. Shall I stop down even further?

[Bob Salomon]

I refer to light fall-off so #1.
I shoot at f/22. Shall I stop down even further?

No, then you will be in to diffraction.

[xkaes]

OK. There's been quite a bit of discussion about this on this forum lately -- as mentioned above. Some people buy the appropriate CND filter, others, like myself, don't see it as a bit deal. Stopping down more might help a little, but is not a solution. Others will have advice about this. Some like the effect of having slightly darker edges on the print because it draws the eye toward the subject. If you shoot with negative film, you can dodge the edges, but that's not easy, plus where there is less detail in the film, there is no way to "get it back". All that does is gives the edges more consistent tonality -- NOT detail. Some suggest using the enlarging lens open all the way -- where it has more light fall off and works in reverse. But, again, that just modifies the tonality, it does not bring back detail that is not there.

[Dan Fromm]

Thanks, Emmanuel, for directing the OP to my piece on center filters.

OP, with lenses for LF there's no way around cos^4. Live with it or buy a center filter.

However, as Emmanuel pointed out, a retrofocus lens might (great stress might) help you if one could be found. At least one Komura LF lens, the 75/6.3, has been reported to be retrofocus.

I have no idea whether it is retrofocus enough to make a difference, where you can find one, or how much you'll have to pay for one. Live with dark corners or buy a center filter.

Now that I think of it, f/4.5 Biogons (38, 45, 53, 60 and 75) have illumination that falls off with cos^3. A 75/4.5 Biogon centered on 4x5 will give corners that are 1.5 stops darker than the center. Big, heavy expensive lens. Live with your 75 SA's cos^4 or get a center filter.

[Neal Chaves]

Are you using a filter on the lens? If you must use a filter, use a larger size in a step-up ring.

[Luis-F-S]

A 75mm Super Angulon should have an adequate image circle at f/22 with minimal vignetting for 4x5. Perhaps there is something wrong with the assembly of the lens elements?

Or with the OP's technique or lack there of! I've never had any issues getting a 75 Nikkor to cover 4x5 without a center filter, even with chromes.

[Mark Sampson]

In any case, light falloff is more apparent when working in color, especially transparency films. This effect is exacerbated by the high-contrast nature of some of these films, such as Fuji Velvia. Without seeing the OP's photographs which demonstrate his problem, it will be difficult to diagnose, though. That said, i would tend to rule out a problem with the lens itself, unless it shows major physical damage. (I've used a 75/4.5 Nikkor-SW for many years and don't really have a falloff issue with that lens, at infinity or at closer distances. I do avoid the most extreme movements.)

[Dan Fromm]

A 75mm Super Angulon should have an adequate image circle at f/22 with minimal vignetting for 4x5. Perhaps there is something wrong with the assembly of the lens elements? For comparison, I've used a Nikkor 75mm SW (without centerfilter) for 5x7 and only have to deal with an acceptable amount of vignetting (see my shot below).

http://mdfedart.com/mfaentry/artworkentry/images/97_32615_5_1.jpg

Hmm. Per my calculations and Rodenstock documentation, with a 75 mm lens shot centered on 4x5 the corners will be 1.5 stops down from the center. That's a fact. Some find that much optical vignetting acceptable, others don't. Its a matter of personal preference. That's another fact. There's no profit in arguing about preferences or facts.

Per my calculations, with a 75 mm lens shot centered on 5x7 the corners will be a little over 3 stops down from the center. I think your example print is considerably cropped or manipulated (corners burned in).

I didn't make the point in my center filter piece, but there's also mechanical vignetting. Mechanical vignetting can be reduced by stopping down. Optical vignetting can't. People often confuse the two effects.

Take a look at my CF piece, link to it in post #4, and also at its companion on the Horseman light meter at http://www.galerie-photo.com/horseman-4x5-exposure-meter.html

[xkaes]

That's a great way to clarify the definitions we are dealing with.

Here are my results from the Fujinon SWD 75mm f5.6 -- and other lenses. This was discussed on another thread. You might want to search for it.

167621

This is light metered on the ground glass. It shows the optical fall-off from the center to the corner. With the 75mm, I measured it as a 0.5 f drop-off at f16 -- MUCH less than what I was expecting. I 'm sure it's more than that and has to do with the limitations in my metering method. I only use negative film and it doesn't bother me.

Here's a shot with a my Fujinon SWD 65mm f5.6 in Zion -- probably f22 -- with Agfacolor 100. No manipulation, only a UV filter. The 65mm has even more optical fall-off, but it's OK by me. My 47mm??? That's another matter.

167622

As Dan said, it really all comes down to your personal decisions. I love my wide-angle results -- DAMN THE TORPEDOS!!!

[Dan Fromm]

You get partial credit. It is not considerably cropped. I'd say maybe 1/8 to 1/4 inch was trimmed off each end of the 7 inch dimension, while nothing was trimmed in the 5" dimension. The other thing I did was use the "vignetting compensation" tool in Adobe Camera Raw when I opened the scan from the 5x7 negative. Easier and cheaper than buying a centerfilter for 3 or 4 different wide angle lenses...

Professor, I think I earned full credit.

[xkaes]

OK, Adobe may be great, but it can't work miracles -- like putting detail in where there isn't any. A CND makes sure the detail is actually captured on the film. Only Rod Serling can create what isn't there.

[tgtaylor]

Although I seldom use a 75mm lens on a 4x5 I haven't noticed and falloff with my 75mm Rodenstock Grandagon. This is not a great scan but it was taken with the 75mm Grandagon on a Toyo Robos camera in available interior lighting of a mausoleum on Porta 160nc color negative film. A CF was not used.

167632

Thomas

[Dan Fromm]

Um, er, perfesser, I were slightly mistaken. If the corners of a negative are underexposed they're less dense than the center. Dodging them, not burning them in, is needed to make the print less dark in the corners than it would be without dodging. My slip.

You still cheated.

[consummate_fritterer]

delete

[AtlantaTerry]

I have a 75mm Congo that is attached to a Cambo recessed lens board.

Does anyone here know if a neutral density central filter is available for it?

Before anyone asks, right now I can't remember the thread pitch. I will go look in my notes.

[sergiofigliolia]

Hi all,
thanks everyone for the responses.
This is the image where the effect is stronger:
167665
I did not use any filter at all and it was shot at f/22

[xkaes]

Thanks for the picture. To me, it shows that it just comes down to personal preference and subject matter. In your example, I don't find it offensive at all, in fact, what little optical fall-off there is actually helps. But that's just my personal preference. Here's an example of a little TOO much for my taste:

167667

I have no idea if it was intentional -- but it certainly could be.

I should add that with wide lenses, it becomes more important to make sure your image falls on the middle of the ground glass. I don't mean the subject. I mean the optical (or mechanical) light fall-off will be minimized if the optical center of the lens is in the dead center of the GG. There has been a discussion on this issue going on lately on this forum. I encourage you to check it out.

[Dan Fromm]

I have a 75mm Congo that is attached to a Cambo recessed lens board.

Does anyone here know if a neutral density central filter is available for it?

Before anyone asks, right now I can't remember the thread pitch. I will go look in my notes.

Terry, read my article. Link to it in post #4 in this thread.

Short answer, Yamasaki didn't make center filters but there may be one that will fit and is the right density.

[Emmanuel BIGLER]

Terry, read my article. Link to it ... (http://www.galerie-photo.com/center-filters-for-large-format-lenses.html)

[sergiofigliolia]

... it becomes more important to make sure your image falls on the middle of the ground glass. I don't mean the subject. I mean the optical (or mechanical) light fall-off will be minimized if the optical center of the lens is in the dead center of the GG.

You mean to not use much rise/fall/shift of the front standard, I guess

[xkaes]

Back in grandpa's day, there were a couple of accessories that were not intended to solve optical light fall-off, but just might help. I know a little about a couple of them. There might be other ones, and it appears that it would be easy to make one yourself.

The first is the PICTROL. It was designed to create soft-focus images on camera or on-enlarger.

167670

The adjustable blades could be moved in or out, and were clear (but not too clear). It just created as much fuzziness -- as desired -- without impacting the exposure. However, if the blades were simply painted black and used on an enlarging lens with a negative "suffering" for unexposed edges, this might decrease the exposure under the enlarger, and achieve a more consistent tonality.

There may have been different versions of the PICTROL.

Similarly, there were a few versions of the VIGNETTER. Here's four of them in an old ADORAMA catalog. One was similar to the PICROL. It was adjustable but it had opaque blades.

167669

These items might be useful "as is" or modified, and useful in reducing the impacts of optical light fall-off. In any event, they were all REALLY cheap. I'll have to check EBAY.

Any thoughts?

[Dan Fromm]

You mean to not use much rise/fall/shift of the front standard, I guess

Almost exact. No decentering movements at either end.

But this isn't a firm rule and you shouldn't follow it slavishly. For example, converging verticals can be a worse problem than dark corners.

[xkaes]

You mean to not use much rise/fall/shift of the front standard, I guess

Yes.

Many wide-angle lenses have lots of optical light fall-off AND a very small image circle. If your GG is not perfectly centered on the lens axis, you will be closer to the edge of the image circle where the optical light fall-off will be at its maximum. Making sure your lens and GG are aligned will decrease -- as much as possible -- the optical light fall-off.

[Dan Fromm]

Um, Joe, you may be remembering the extremely extreme wide angle versions of the Goerz Hypergon, which came with a mechanical center filter. See http://web.archive.org/web/20161204154713/http://www.cameraquest.com/hyper.htm for a full explanation.

http://web.archive.org/web/20160506045622/http://matmarrash.com/blog/2015/5/12/just-one-more-lens-i-promise has a clearer image of the star in place, ready to be spun.

The devices you described won't, unfortunately, do the job. When the Hypergon's star spins it acts like a disk who density is highest at the center. Your devices don't spin.

There really is no substitute for a center filter.

I didn't discuss the center filters supplied with Metrogon lenses in my article. These are clear filters with a pattern of small dots deposited on them. Dot density is highest at the center, falls off away from the center and there are no dots at all towards the edge. Its been a while, but I've seen discussions (here, I think) about how to calculate and lay down the dot pattern.

I'm a tinkerer but I've found searching for used CFs a better use of my time than trying to make my own. Others who are better and more serious tinkerers may go the other way.

[xkaes]

Hi Dan,

I was not trying to suggest that any of these tools could solve the optical light fall-off problem -- just simply minimize its appearance, AKA "make it less obvious" to the viewer. The Adorama Vignetter #2 simply dodges the edges of the paper so they won't come out as dark. You could do the same thing with your hand, but the Vignetter #2 covers the entire image at once, has an opening that is adjustable -- even more so than a typical aperture -- and is moveable during the exposure -- up & down, or rotating -- to minimize the edges of the tool. A longer exposure of the paper makes this easier.

I've used a hand-made tool -- just a hole in a piece of cardboard to lighten the edges of portraits -- using camera lenses with no optical light fall-off. Anyone who has done a lot of portrait work has done that. I never thought of it before, but it seems to me that it can do the same thing in reverse -- lighten edges that would otherwise come out too dark due to optical light fall-off. Of course, it would not bring back detail that was no there, but tonality would be improved.

[Pfsor]

The devices you described won't, unfortunately, do the job. When the Hypergon's star spins it acts like a disk who density is highest at the center. Your devices don't spin.
There really is no substitute for a center filter.


+1. Not only will it not do the job but who would like to exchange light fall-off in a picture for fuzziness in it?

[xkaes]

You're missing the point completely. It doesn't ADD fuzziness. It simply cuts out light from the edges of the paper so they don't appear as dark as they would. And who cares if they actually added fuzziness? There is no detail on the edges anyway!

Take this photo:

167671

The corners are WAY too dark -- at least for my taste. Let's assume that was due to optical light fall-off.

If the corners were simply dodged during the exposure of the paper, the corners would be lighter. Would there be more detail in the corners? Of course not, but they would not be so horribly dark. Would they somehow become fuzzier? Of course not. All you are doing is cutting out light. If you have a tool that can do this, it will make your life easier.

How much to dodge would simply be another artistic decision.

[xkaes]

There are a couple of TESTRITE Vignetters on EBAY right now that some of you optical light fall-off sufferers might want to consider. Sure, it's the "Po' Man's" route -- especially after buying a wide-angle lens that suffers from optical light fall-off AND/OR a small image circle.

So #1 -- make sure the lens is the right one for you -- regarding cost, image circle, optical light fall-off, size, weight, etc. I have THREE troublemakers.

#2 -- Maximize your image circle by getting your ground glass and lens perfectly aligned.

#3 -- Stop down as much as you can. This depends on your needed DOF -- which fortunately is pretty substantial with wide-angle lenses -- and your ability to tolerate diffraction.

#4 -- Look at Center Neutral Density filters. Sure, they help, but at a cost -- unless you get lucky!

#5 -- Consider after-exposure adjustment. This can be under the enlarger with dodging the edges/corners on the paper -- or using a mask in a computer.

[Pfsor]

The first is the PICTROL. It was designed to create soft-focus images on camera or on-enlarger.

The adjustable blades could be moved in or out, and were clear (but not too clear). It just created as much fuzziness -- as desired -- without impacting the exposure.

Any thoughts?


You're missing the point completely. It doesn't ADD fuzziness. It simply cuts out light from the edges of the paper so they don't appear as dark as they would. And who cares if they actually added fuzziness?



It doesn't add fuzziness, it just created as much fuzziness, as desired. Don't try to pull my leg, I recognize nonsense when I see it.

[xkaes]

It CAN create fuzziness, but if modified, it COULD be used exactly like the Testrite Vignetter #2. I'm not trying to pull anyone's leg. I'm just offering a possible approach. If you think it will only create fuzziness, that's fine with me. More power to you, others may see a useful tool.

[Pfsor]

As Dan tried to explain to you -
because the parts do not move they can only create the effect on one part of the picture and leave the other part unchanged. In the moment when the effect is visible its limitation will be also visible. It just replaces one problem with the other one. It cannot replace the function of a CF.

[xkaes]

It does move -- in several ways. During the exposure, you can move it up and down, side-to-side, and the aperture diameter and shape can be changed -- even during the exposure.

And no one suggested that it will replace a CND -- only that it can help MINIMIZE the problem.

[xkaes]

Here are some shots of the Testrite Vignetter -- they came out with different models, but this is the one I have.

As you can see, it is basically a thick hunk of paperboard with a couple of dozen opaque, serrated blades. They can be reversed so that the smooth/acute side is in the middle.

167946

The opening can be adjusted as to the shape and size. All it does, it diminishes the amount of light that hits the edges of the paper.

167945

You achieve a very smooth gradient by moving the vignetter up/down, rotating it, etc.

167939

It was designed to produce white/brighter edges, as in portrait/wedding shots.

But it can be applied to shots taken by lenses "suffering" from optical light fall-off that would create darker edges.

167947

Whether you are dealing with a lens that just has a little fall-off such as a 105mm or 90mm, or a lens that makes you think about a center neutral density filter, such as a 75mm or 65mm, or a lens that needs help, like a 47mm, a vignetter can "ease the pain" and lighten up the otherwise dark corners -- at a fraction of the cost.

[Dan Fromm]

Um, Joe, you're talking about dodging when printing. Exposure times when taking are usually too short to make the device usable then. Dodging has already been mentioned.

The rest of us have been talking about using center filters to make exposure more even across the field when taking. This has a great advantage over dodging when printing. With narrow latitude film, e.g., reversal film, what's lost to underexposure can't be recovered.

[Pfsor]

Dan,
it moves and it is cheaper. Be happy!

[xkaes]

Yes, I'm talking about dodging the edges -- which otherwise would come out too dark. With a "dodger" -- in this case, called a "Vignetter" -- it can mimimize the "damage" caused by optical light fall-off. I have TRIED, but apparently failed, to point out that it will not bring back detail that isn't in the negative. All it does is create a more consistent tone in the print.

That's why I referred to it as a "Po' Man's Approach".

As to it's use, my enlarger prints are typically more than 20 seconds, and I can always make them much longer simply by stopping down or using a ND on the enlarging lens. Many of my large prints are several minutes of exposure. There is plenty of time to use a dodger like this, in my opinion.

It is easier to use where there is just a little fall-off -- like a 90mm -- but with patience, it can make a big difference with more extreme cases of fall-off.