Multicontrast filters for 8x10 printing

[ic-racer]

Just wondered what people are using for filters if you don't have a color head? Looks like the 8x10 Ilford filters cost about $20 each from B&H. For that much money I'd rather seek out a color head.:p

Anyone using Roscoe filters? Looks like you can get Yellow in 15, 30, 60 and 90cc and Magenta in the same http://www.rosco.com/us/filters/calcolour.asp

B&H sells the Roscoe filters as 20x24 inches for about $6.00 each. This is enough to double the 60 and 90 to make additional 120 and 180 filters. So, it looks like for about $50 you could have a wole set from 180cc yellow to 180cc magenta.

180Y, 120Y, 90Y, 60Y, 30Y, 15Y, none, 15M, 30M, 60M, 90M, 120M, 180M

Anyone tried this?

[Dave Brown]

The cheapest solution would be a set of under the lens filters (although I doubt they would be large enough to cover the 300 mm Rodagon on my Durst). I know many people are concerned about a loss in image quality with under the lens filters, I've never seen any proof that when properly used there is a significant degradation in image quality.

Having said that, I think your idea of using Roscoe gels is an excellent one.

Good luck.

[Nick_3536]

8x10 enlarger or contacts?

Split filter with the Roscoes. You only need two of them.

[Eric Woodbury]

I use Roscoe for a little extra boost into high contrast. I have the blues. Otherwise I use the standard Ilford set under the lens cut from 6" square in 4" cardboard filter frames. These are large enough to work with a 210mm El Nikkor. There is no loss in image quality.

I'm using a V54 12x12 coldlight.

[Mark Woods]

I use the Besler 12x12 coldlight and some Besler 6x6 filters that came with the enlarger. If you can find an outlet that sells the Rosco filters, you can get a swatch book with all the filters for FREE. I have a couple of swatch books that are 4x6 and use them in front of the lens when I shoot my LF camera. They work great. I keep them in a baggie to keep them clean.

[Chuck Pere]

I use the big (12x12?) Ilford set. I mounted them on black foamcore and have a homemade filter drawer under my Aristo 1212 with V54. I do find I use a lot of double filtering to get to the contrasts between the numbered filters. Love to have that Aristo VC head for 8x10 size. But expensive.

[Mark Woods]

When I initially set up my cold head, I used a CC15 Rosco, I believe that approximately matched it to my globe 4x5 head. I did this so I could use past times for past images. As it turns out, I redo everything from scratch when I go into the vault to make prints.

[ic-racer]

I use Roscoe for a little extra boost into high contrast. I have the blues. Otherwise I use the standard Ilford set under the lens cut from 6" square in 4" cardboard filter frames. These are large enough to work with a 210mm El Nikkor. There is no loss in image quality.

I'm using a V54 12x12 coldlight.

I don't know about the "standard Ilford set." Are they glass or gelatin?

[ic-racer]

8x10 enlarger or contacts?

Split filter with the Roscoes. You only need two of them.

This would be for 8x10 enlarging.

I never saw the point of the split contrst method when you can just dial the contrast in on the color head and do one exposure. But now I see a utility in the method. I would be able to just buy the hardest and softest big Ilford filters for the filter drawer about $40 and I'd be set. Thanks, that's a good idea.

I just wonder if I won't have to make twice as many test prints? ie one for the blacks with the Magenta and one with the Yellow for the whites. Is that right?

[Nick_3536]

Usually for me I end up with less test.

One for the low contrast [or high depending on how you start]

One for the total exposure.

Thing is the two tests will get you contrast and exposure.

[sepiareverb]

The Rosco method will work, but times are all over the place.

[EdWorkman]

I use roscoes in the Beseler
I find the bare coldlight very contrasty for typical negatives, but I do occassionally [never could spell that right] need to bash up the contrast.
I use "minus green"- which is magneta for that.
I almost always need a little less contrast and use the "plus green" series.
They are available as "plus green" "1/2 plus green" and "1/4 plus green" so I can use "1/4" increments for combinations.
Yes, as no gratuitous red is added each combination requires a time change, but the so-called constant times that "real" filters feature are for middle tones in any case- the region where one doesn't need much contrast change anyhows.
So I'd characterise the time changes as larger than those of real filters. After you beat your brains out with experience the time changes are no big deal- About 2x from bare to 1 green , another x for another half or so.
Enjoy

[Robert A. Zeichner]

There was an article in a Photo Techniques not too long ago written by Howard Bond. In it he lists some Rosco gelatin filters that he has tested and compared to specific Ilford filters. I don't recall the exact issue.

[neil poulsen]

Another recommendation for Roscoe filters is in Steve Anchell's book on VC Printing. I misplaced my copy and haven't found another. Otherwise, I would transcribe it here.

I believe it might be on the Photo.Net LF site archives.

[ic-racer]

Potential problem: Looks like I was mistaken on the bulb of my Aristo. I was taking it all apart to clean it and the bulb says W45, which I hear, prints more contrasty than the V54.

So, I was thinking of still trying the split grade printing with just two filters, knowing that the exposure time for the high contrast filter is going to be very sensitive to small changes.

I suspect there are people out there that are using the W45 with MC paper and finding ways to work around it, right?

A new V54 bulb is $350.

[Kevin Crisp]

I have a set of the 12" ilford filters and stick them under the light tube but above the translucent diffusing plastic on my Beseler enlarger. I use the 210mm Nikkor, which is too big for conventional below the lens use with smaller filters. Yes, changing filters is relatively inconvenient this way. On the other hand the shorter lens requires less separation of the light source and the lens which makes alignment better. When I'm lazy, I switch to the HD Beseler lens I think it is a 240mm) that came with the enlarger and use the below lens filters.

[Kevin Crisp]

You can try filtering the tube you have for this, I tried the standard recommendations and couldn't get acceptable results. The V54 tube puts out a brilliant aqua color that is not at all like the older tubes. If you do replace the tube, be extremely careful when taking the old one out since they are often glued in and when they break mercury goes everywhere.

[ic-racer]

I was anxious to start printing today, so I went to the local photography store and bought a Rosco primary RED and a primary GREEN, (#27 and #91) for a total of $14.

I'll try these with some split contrast printing. I went for the RED and GREEN instead of YELLOW/MAGENTA, because the 60degree shift on the color wheel may be what I need to match the cold light output to the paper better.

Here is an article on the topic:

http://www.steveanchell.com/index.php?Itemid=98&id=36&option=com_content&task=view

[ic-racer]

I was anxious to start printing today, so I went to the local photography store and bought a Rosco primary RED and a primary GREEN, (#27 and #91) for a total of $14.

I'll try these with some split contrast printing. I went for the RED and GREEN instead of YELLOW/MAGENTA, because the 60degree shift on the color wheel may be what I need to match the cold light output to the paper better.

Here is an article on the topic:

http://www.steveanchell.com/index.php?Itemid=98&id=36&option=com_content&task=view
Ops, too late to edit. I intended to type BLUE for RED above. (othewise it is like printing with the safelight...:eek: )

[ic-racer]

Just to clarify, the filters I got were Roscoe Blue #80 and Roscoe Green #91. I mounted them on cardboard frames so that I could slide them in and out of the filter holder.

Preliminary tests (test prints, rather than step wedges) show the green to produce low contrast, and the blue to produce high contrast as expected;)

I made some nice prints with the split filter technique. I'll print some step wedges to see the range I can get from max blue to max green.

[Jrewt]

I'm looking for ways to filter my beseler 810, since it's my first foray into both VC paper and enlarging. Roscoe filters + split printing seems like the way to go. Post your results up ic-racer! =)

[ic-racer]

I'm looking for ways to filter my beseler 810, since it's my first foray into both VC paper and enlarging. Roscoe filters + split printing seems like the way to go. Post your results up ic-racer! =)

What light source do you have?

I found the split technique (in only two days of doing it) to actually be fun. I don't do extra test strips (I don't do standard test strips anyway for other reasons). I just expose a little strip of paper to a common spot on the image (two exposures that is; one for each filter). I make adjustments based on a 'first guess' and go from there. So, instead of thinking how I will change my color head filtration and exposure for the next exposure, with the split techinique I just think about the changes in exposure for highlight (green) and shadow (blue). So, in terms of zeroing in on exposure and contrast I found it to be nearly identical in number of little proofs comparted to a color head.

A little OT but I have never used the conventional multi-exposure 'test strip' because each 'strip' shows a different part of the image. The concept of testing different parts of the image with different exposures is too complicated for me :p

So, the little extra time to re-set the timer and swap the filters for each exposure compares very favorably against the weight, bulk, heat and expense of a typical Dichoro 8x10 head. (though I'm still going to keep an eye out for a CLS1840 head if it comes along...)

So, after 23 years of VC printing with a color head I can say this split printing really can do everything a fancy color head or VC head will do.

[Nick_3536]

Split filtering with a colour head is even easier. Just spin some dials.

[ic-racer]

Split filtering with a colour head is even easier. Just spin some dials.

If you have a color head why make two exposures when you can just make one?

[Nick_3536]

Just check any of the threads on split filtering.

But basically

You get to control contrast with dodging/burning

You get to judge contrast with your exposure test prints

Some of us just find it works better/easier for us.

[Jrewt]

I have a beseler cold light head. I'm just waiting to get my lens back from SK Grimes and I'll be ready to print. I have a really old beseler 23cII with the 6x6 conversion and aristo cold light as well, and have had a hard time with the ilford 6x6 filter kit. I've only been printing with it for a few weeks now, and new something was up, but didn't suspect the filters right away. Just realized that ilford filters were made for incandescent and not cold light, which makes sense. I'm going to order up a couple of rosco filters tonight!

Cheers


What light source do you have?

I found the split technique (in only two days of doing it) to actually be fun. I don't do extra test strips (I don't do standard test strips anyway for other reasons). I just expose a little strip of paper to a common spot on the image (two exposures that is; one for each filter). I make adjustments based on a 'first guess' and go from there. So, instead of thinking how I will change my color head filtration and exposure for the next exposure, with the split techinique I just think about the changes in exposure for highlight (green) and shadow (blue). So, in terms of zeroing in on exposure and contrast I found it to be nearly identical in number of little proofs comparted to a color head.

A little OT but I have never used the conventional multi-exposure 'test strip' because each 'strip' shows a different part of the image. The concept of testing different parts of the image with different exposures is too complicated for me :p

So, the little extra time to re-set the timer and swap the filters for each exposure compares very favorably against the weight, bulk, heat and expense of a typical Dichoro 8x10 head. (though I'm still going to keep an eye out for a CLS1840 head if it comes along...)

So, after 23 years of VC printing with a color head I can say this split printing really can do everything a fancy color head or VC head will do.

[ic-racer]

First step wedges last night with the Rosco green and blue.

Rosco PRIMARY BLUE: 0.9 log = ISO 90 contrast = about grade 3
Rosco PRIMARY GREEN: 2.1 log = ISO 210 contrast = about grade 000

This is enough range to print many of my negatives right now. But there is some room to tweak with some different filters as it is on the soft side.
Here is a link to Ilfords info on the W45 head: http://www.ilfordphoto.com/Webfiles/2006130201152306.pdf

[ic-racer]

I did some better step wedge tests today. The goal here is to try to get this existing Aristo W45 coldlight to perform well with VC paper, so that I don't have to buy a new head. Obviously, the easiest answer to this question is to just buy a head that is known to work well with VC paper.

The idea was to see the effect on tonal scale of YELLOW, CYAN, GREEN, BLUE and MAGENTA from the mini color head and also the effect of the two Rosco filters (Primary BLUE and Primary GREEN). Ilford MG RC was used for the tests.

The testing setup consisted of a modular dichroic head and diffuser from another enlarger that was placed between the unflitered Aristo 1414 coldlight and the contact printed test wedge. The test wedge is a 21 step, un-numbered (so I could not make good 'relative speed' comparisons), with .15 log (1/2 stop) between steps. The wedge is un-calibrated, but I checked it with my calibrated densitometer and the steps progress in a reasonable fashion.

To test the Rosco filters, I set the mini color head to 00cc (white) and just placed the Rosco filter over the assembly.

Here is a picture of the testing setup.

[ic-racer]

MAX MAGENTA: 0.60 log = 60 ISO = Grade 4
Rosco BLUE: 0.75 log = 75 ISO = Grade 4
MAX CYAN: 0.90 log = 90 ISO = Grade 3
NO FILTER: 1.05 log = 105 ISO = Grade 2.5?
MAX Y & C (GREEN): 2.1 log = 210 ISO = Grade 000
MAX YELLOW: 2.1 log = 210 ISO = Grade 000
Rosco GREEN: 2.1 log = 210 ISO = Grade 000


Interpretations:
1) The Rosco blue filter had more contrast than I tested yesterday, this was a technical problem with yesterdays test (no pressure on the test wedge contact print with light leaking around the step wedge)
2) The contrast from Magenta or Blue is similar, or perhaps identical within experimental error.
3) The contrast from Yellow or Green is identical.


I did not use a numbered step wedge and I did not keep the test strips all lined up, and I fiddled with the exposure for each test to get the whole scale on the test strip. Therefore I don't have good speed comparison. BUT, just from the time needed to get a good strip I can say that the two Rosco gels are like 1-2 stops slower than the dichroic filters, with the same effect on contrast.

Conclusions with respect to Split Grade Printing with MY Aristo 1414-2, W45 head:
1)The Rosco filters are cheap and easily available and yield VC paper contrast similar to dichroic filters. The Rosco filters I tested are just slower.
2) There is little or no difference in contrast between BLUE and MAGENTA or between YELLOW and GREEN.
3) Therefore, any of these combinations of filters will work to give a reasonable contrast range with Split Grade Printing: GREEN & MAGENTA or GREEN & BLUE or YELLOW & BLUE or YELLOW & MAGENTA
4) With the filtering I had available to me and the intrinsic characteristics of the W45 light, Grade 5 was not obtainable.

Where to go next:
That Rosco Green is painfully slow in 'real life' printing. Based on these results, it seems that a faster filter can be obtained. Maybe I will try a Rosco Yellow or the Chroma Green. There is going to be some leeway here because I really don't need a filter to go all the way to a log 2.1 range for general split grade printing.

[Jrewt]

Those are interesting results.. I wonder if grade5 will be obtainable with my head...

[ic-racer]

I did some tests with a double-layer of the Rosco blue, in an attempt to get number 5 contrast.

I think I have reached the point of diminishing returns and the double blue is just ever so slightly higher contrast than the single blue. This may be as much contrast as the paper will give. If it comes out to the correct ISO grade, I can't really tell because I'm not an 'authorized ISO testing facility' :)

It is interesting to note that when Ilford tested the W45 bulb they concluded:

"With the Aristo W45 lamp,... It can be seen that a full contrast range can
be achieved, [with Ilford VC filters] ..."

from: http://www.ilfordphoto.com/Webfiles/2006130201152306.pdf

[Nick_3536]

Using two of the same filters should be no different then one filter.

The first filter will pass some light frequency.

The second filter will pass the exact same light.

[ic-racer]

Using two of the same filters should be no different then one filter.

The first filter will pass some light frequency.

The second filter will pass the exact same light.

Thank you, that's right, I'm just making neutral density. That's why I'm posting this as I go, so I can be double-checked.

I checked my Rosco Primary Blue diagram and it has a little hump in the cyan/green area, that's what I need to get rid of. Looks like the CC90 will be better. I'll check with my local store to see if they have that CC90B.

After buying too many of these Rosco filters, I might be better off just to get the Ilford 00 and 5 filters at $20 a piece, but what's the fun in having it all figured out already;)

[ic-racer]

So, the main problem with the Rosco Primary green is that it is very very slow. I would gladly give up some softness in contrast in exchange for more speed. ie a little blue in the filter.

Here is the Primary Green (#91) and two others I might try. The Chroma Green looks like it will be very fast (tall peak) but has a little cyan in it. I guess the only way to know for sure is to test it.

[ic-racer]

A swatch book would be great for testing; turns out the Rosco site has a page to fill out for a free one. I may hold off more testing until the swatch book arrives.

[Jrewt]

20$ a piece is a little steep for 2 filters! I have a set of 6x6 ilford filters, but the lowest contrast filter is 1/2. Don't know why 0 or 00 isn't included! I don't think I'll spend 20$ on ONE filter =)

[ic-racer]

20$ a piece is a little steep for 2 filters! I have a set of 6x6 ilford filters, but the lowest contrast filter is 1/2. Don't know why 0 or 00 isn't included! I don't think I'll spend 20$ on ONE filter =)

I was looking at prices on the B&H web site and the description of those 6x6 Ilford filters is that they can also be used UNDER THE LENS. This is news to me. If that is the case, the stalk on my lens board can easily hold two filter holders that can be flipped in and out. Or just stick a Roscoe yellow up in the filter drawer and use the set of filters in the standard manner under the lens.

I measured the image circle at the level of my under the lens filter holder and it is 3.5", so I don't think those 3" Ilford filters with the holder will work.

Anyway, here is the list of all the other options I could find:

FOR FILTER DRAWER:

Roscoe 20x24" = $6 per filter

Ilford 12x12" = $20 per filter

Kodak acetate 12x14" filters = $80 per filter.

UNDER THE LENS FILTERS:

6x6" glass filter = $320 to $400 per filter

Round 86mm screw in filter for the Rodenstock 300mm/5.6 = $124 to $150 per filter

Kodak Wratten filter 4x4" = $50 to $100 per filter

Optiflex 4x4" = $35 per filter

Lee filter 4x4" = $20 per filter

Ilford 6x6" (Can really be used under the lens??) = $45 (whole set only?)

[ic-racer]

Well, I splurged on another $6 filter and got the Rosco 389 Chroma Green. Based on the transmission spectrum I was expecting more speed with perhaps some loss of range.

Just because I am not using 'standardized conditions' and all these tests are 'relative' I re-tested all filters on the same test strip. This also gave me relative speed info. So, the numbers may not all be the same as yesterday's tests.

#91 = Rosco Primary Green
#80 = Rosco Primary Blue
#389 = Rosco Chroma Green


Log values:
#91 = 2.10
#389 = 1.95
#80 = 0.60
Bare = 0.90


Relative speed to 'middle gray' (the step in the middle, between the black and white; not some standard gray value)

Bare = +1 stop
#80 = 0 by my definition
#389 = -1.5 stop
#91 = -3.5 stop

So, I knew #91 is really slow, but now I have a number for it.

The conclusion is that for less than $15USD a nice balanced set could be made from a singe #389 and a double #80. Again, doubling it just for extra density (the $6 gets you get enough material to make 2 filters).

[ic-racer]

Why do you need a balanced pair? I didn't think it was that important, like 'so what' if the green is 80 seconds and the blue is 1.5 seconds, my electronic timer can handle it.

The problems came when I went to change the aperture without changing overall exposure. Doubling 80 and doubling 1.5 were not the same. The slow time IS reproducable, however, because of afterglow or whatever else, 3 seconds was not the real double. If both times had been close to 80 sec. or close to 1.5 sec, changes in aperture would have been more predictable.

Up until now I have been avoiding chaniging the aperture in the middle of the test print sequence.

Tonight I will try the #80 as single and double, along with the #389.


You might ask why I would want to mess with the aperture, and it is only because the 300mm Rodenstock is new to me and I am curious to see how it responds to different settings on the aperture scale. Some of my shorter lenses are really useful only over a small range (f8 or f11). Under the magnifier this 300mm lens seemed to not have any change in edge sharpness or detectable diffraction over a large aperture range. Curious to see if this holds up during printing.

[ic-racer]

1) A very quick and inexpensive way to do MC or VC printing is to use Rosco filters
2) A combination of #389 Chroma Green and a double layer of #80 blue will make a good combination for 'split grade' printing. The contrast range is about the same as a dichric head that was tested. About 00 to 4
3) I could not detect a speed or contrast advantage to blue vs magenta or yellow vs green and I suspect there are many other Rosco filters that will give excellent results.



What's next?

This temporary solution with the Rosco filters worked so well last night that it could easily function as a permanent solution. Altough the split grade printing concept seems to be favored by many, I need more control over middle gray values (though the prints I made last night were some pretty fantastic; my first good 8x10 projection print enlargements to 11x14).

I imagine that if I were to stick with the two filter technique I will make up a chart of color ratios (contrast grades) and exposure factors for each color. This way I can work in a manner more suitable to my style. That is to say (a) set the grays and the overall intensity of the image with exposure first then (b) adjust the contrast, pivoting on the grays (ie blacks blacker at the same time that whites get whiter).

So what the chart would do would let me go from a ratio of say 3:1 (Grade X) to 2:1 (Grade Y) and keep the middle grays constant. It really will be easier than calibrating a color head. I just need to choose some ratios and do step-wedge prints at the same TOTAL exposure. Then just line up the middle grays, counting the number of steps the deviate from each other, realizing that each step on my wedge is 1/2 stop. So my chart will show 1:1 as defined as 0 for the factor. Then 3:1 may have -1/2 stop for the factor and 2:1 may have -1 stop for the factor. So to go from 3:1 to 2:1 I will just calculate the resultant factor (1 - 1/2 = 1/2) and apply that to get my new TOTAL exposure. With this number I apply the new ratio (2:1 in this case) to get my individual exposures.

[ic-racer]

Here are my graphs I made up so that I can print the way I want to print. These graphs let me change contrast without messing up my middle values.

The Y axis is exposure with the Blue #80 Roscoe filter doubled on itself. The numbers represent seconds.

The X axis is the exposure with the Green #389 Rosco filter (single).

Each colored line represents a series of theoretical exposures where the middle gray stays constant. (The Yellow line from 21 blue to 42 green is actual data (10 datapoints), the other curves are all calculated assuming no failure of receprocity)

The radial lines are lines of constant contrast. Of course any intermediate value is possible, the lines pictured are just the ones I happened to test. The numbers by the lines represent the density range in log units. It roughly goes from grade 5 to grade 00.

The graph is simple to use. From any point in the graph, to make a contrast change without changing the middle grays, just move paralell to one of the colored lines to your new contrast grade. The graph will then show you the new times for green and blue.

For a density (overall exposure) change, you really don't need the graph, just mulitply or divide each individual exposure by your favorite factor (I usually use 2 for a big change and 1.4 for a small change and 1.185 if I want to make a change I can't see :))

So, with the graph, it lets me print just as if I had a color head, or MG filters or a MG head.

[ic-racer]

Using two of the same filters should be no different then one filter.

The first filter will pass some light frequency.

The second filter will pass the exact same light.

I can't seem to confirm this. Seems as if Zaka and Todd are saying the opposite. They indicate that combining like filters give additive effects (not extra neutral density). (H.N. Todd and R.D. Zakia, Photographic Sensitometry: The Study of Tone Reproduction)

As an example. If we combine two #80 primary blue filters, the transmission for the blue peak (420) will go from 63% to 31.5%. The green part (520) will go from 15% to 7.5%.

If you compare that with the effect of combination of one filter with a neutral density filter you will see the resulting filter will be different from above. The neutral density filter, by definition, will affect all the wavelengths the same. So, a 7.5% ND filter will make the 63% blue peak go to 55.5% and will make the 15% green peak go to 7.5%.

[Turner Reich]

Bump.

A single #389 and two #80 filters with an Aristo W45 cold light head placing the filters under the cold light head plexi will provide the correct lighting for Split Grade printing; is this correct to date?

I am going to order them from where, B&H or Rosco? Will the filters being taken in and out create dust problems for the negative? Would it be better to put the filter above the plastic and under the actual bulb?

Thanks for the detailed information you have shared with us.

[ic-racer]

Bump.

A single #389 and two #80 filters with an Aristo W45 cold light head placing the filters under the cold light head plexi will provide the correct lighting for Split Grade printing; is this correct to date?

I am going to order them from where, B&H or Rosco? Will the filters being taken in and out create dust problems for the negative? Would it be better to put the filter above the plastic and under the actual bulb?

Thanks for the detailed information you have shared with us.

Yes, I have not changed from those two for almost a year. Again, there may be other combinations that will work well, once I determined those to give the full range, I stuck with them.

I got mine from my local store, otherwise I would go with B&H.

They are cheap enough that you can try them with a step wedge to confirm and not be out a lot of money of not satisfactory. I had enough to cut both blue filters from one sheet. My impression from studying the spectra graphs on the Roscoe site is that there were perhaps 10 or so filters that would work for the 'high contrast' filter and probably 10 or so that would work for the 'low contrast' filter.

In terms of dust, I had re-positioned my plexiglass diffuser closer to the negative carrier than original. So, now my filter drawer is between the plexiglass diffuser and the bulb.

Those filters tend to really collect the dust.

In terms of getting the filters in and out of the filter drawer, they are too flimsy on their own (for an 8x10 enlarger). I tried a number of things with various levels of success. I tried a cardboard frame, but it needed to be 1/4 inch on the edges and that made it too flimsy. Once it got caught in the filter drawer and I had to take the whole thing apart to get it out.

I settled on using transparent tape to affix the filters to appropriately sized pieces of 'clear' plexiglass. These slide in and out of the filter drawer without taking the drawer totally out. These can get scratches on them, but in my case, they are between the light and the diffuser panel, so the fine scratches are inconsequential.

[ic-racer]

This board is very, very useful for keeping track of the exposure times. The coordinates of the pin, of course, represent the two exposure times. Since I now do all test exposures with the same color first, that means re-setting the timer quite a bit.

The paper does not care if the high or low contrast exposure is first, but the time/intensity characteristics of the my Aristo 1414 W45 lamp suggest prudence in maintaining the same exposure sequence. Now, I always do the same color first (I try to guess which will have the shortest time, usually blue)
http://img.photobucket.com/albums/v670/ic-racer/IntensityTemp.jpg

(error in the diagram title, should indicate Aristo 1414)

[ic-racer]

Just to add to this thread. In addition to the split grade printing, I want to be able to use the full-set graded Ilford filters. I made this holder for the 6x6 filters. (I have yet to order the filters from B&H.) Should cost about $50 for these filters (as opposed to $210 for the 12x12 filter set)

http://img.photobucket.com/albums/v670/ic-racer/finished1-1.jpg

[Drew Wiley]

I use regular blue or green camera filters right on the enlarging lens for split printing.
My coldlight for 8X10 is blue-green, and this works perfectly for every variable contrast
paper I've tried. I usually make the test strips and one full print without any filters first, then dodge/burn or whatever with one or both of the filters afterwards if needed.
Pretty simple once you get used to it, and the result is the same in the end as using
a colorhead.

[Turner Reich]

Thanks, this is the approach I'm going to put to use. I like that 6x6 holder you made. It's nice to hear that you are pleased with the Rosco filters, I'm ordering them right away.

[ic-racer]

I use regular blue or green camera filters right on the enlarging lens for split printing.

I looked in to that but the ones to fit my 300mm Rodenstock were quite expensive. Do you screw them into the lens or do you set them on a filter holder.

I also looked into two nice glass 6x6 filters, but again the price was almost more than the entire enlarger.

[ic-racer]

Another thing I will mention, that has me dragging my feet with buying the Ilford 6x6 filter set. That filter set will not have even exposure times for me. There is an exposure correction needed with each filter (when using my W45 light.)

So, I was thinking again about making a Roscoe 12"x12" set with 90M, 30M, 15M, 15Y, 30Y, 60Y, 90Y and 180Y. (60M too close to 90M needed because of the high contrast bias of the W45). I would need to mount all the filters on plexiglass and determine my own correction table. I would also need to configure some convenient storage mechanism for all those filters mounted on the plexiglass. On the other hand, the Ilford filters are 'ready to go' out of the box and Ilford has already made the correction table. Plus there is a current APUG thread vouching for the safety of under the lens plastic filters, with respect to image quality. So, it is kind of a toss up.

[Drew Wiley]

Since variable contrast papers have one emulsion which sees blue light and the other
green, a sharp-cutting blue 47 (or 47B) or green 58 (or 61) will cut off the other half
and work precisely with only one emulsion component. You can either use a filter turret
under the lens or just screw the filters onto the lens if your enlarger is stable. Only two
filters are ever needed, and camera filters will provide a much cleaner optical path than
Rosco filters, and hold up better. I use Tiffen filters, which certainly aren't my favorite
filters in the field, but work fine in this instance, provided they are routinely cleaned.
The blue filter is denser and will require a bit longer exposure than the green, but this
differs a little from paper to paper. I don't even think about it anymore since it has
become almost instinctive, and as I mentioned before, the result is the same as if I used one of the colorheads instead. For just two filters, the investment is negligible.
With my coldlight the printing speeds are very fast.

[ic-racer]

From a previous post these were the prices I estabilshed:




FOR FILTER DRAWER:
Roscoe 20x24" = $6 per filter

Ilford 12x12" = $20 per filter

Kodak acetate 12x14" filters = $80 per filter.

UNDER THE LENS FILTERS:

6x6" glass filter = $320 to $400 per filter

Round 86mm screw in filter for the Rodenstock 300mm/5.6 = $124 to $150 per filter

Kodak Wratten filter 4x4" = $50 to $100 per filter

Optiflex 4x4" = $35 per filter

Lee filter 4x4" = $20 per filter

Ilford 6x6" (Can really be used under the lens??) = $45 (whole set only?)

It would nice to have an affordable set of screw in filters, but at $300 and the thought of swapping them out, in the dark, 50 or so times in a printing session, that seemed to out-weight the potential benefit of an 'optical glass' light path, especially when the cheap Rosco filters are not even in the focused light path.

On a somewhat related note, I saw a 'new in box' 80mm enlarging lens with built in adjustable dichroic filters (blue and yellow) at a vintage photo shop the other day. That would have been great if it were a 300mm!

[Keith Pitman]

I looked in to that but the ones to fit my 300mm Rodenstock were quite expensive. Do you screw them into the lens or do you set them on a filter holder.

I also looked into two nice glass 6x6 filters, but again the price was almost more than the entire enlarger.


I have a 300mm Rodagon, also. I already had a Lee filter holder and an 82mm adapter ring. I got a step-down ring for the Rodagon, and use the Lee holder with the 6x6 Ilford filters cut down to 4x6. It works great for me.

[ic-racer]

I have a 300mm Rodagon, also. I already had a Lee filter holder and an 82mm adapter ring. I got a step-down ring for the Rodagon, and use the Lee holder with the 6x6 Ilford filters cut down to 4x6. It works great for me.

If it is the Lee filter holder I am thinking of, that looks like a nice holder. I based my filter holder design on that one.

I looked into buying that at B&H and they wanted $150 for the holder + $60 for the adapter and that was nearly the price of the Ilford 12x12 filter set.

[Keith Pitman]

If it is the Lee filter holder I am thinking of, that looks like a nice holder. I based my filter holder design on that one.

I looked into buying that at B&H and they wanted $150 for the holder + $60 for the adapter and that was nearly the price of the Ilford 12x12 filter set.


I already had the holder. Probably got it used on Ebay for much less, and still use it in the field too.