Contrast difference between contact print and enlarging...

[Vania]

Hi everyone,

I'm facing a very odd problem. My 6X6 contact prints are very well balanced in term of contrast. Printed with a grade 2 filter there's details everywhere in the shadows and the highlights. Now when I print the contrast gets blown away. I have to print with a grade 0 filter AND burn for at least 2 or 3 stops more the highlights to get some details out of it (but it's there). Shadows are fine. I've been forced out of the darkroom for a couple years and I must say the come back is not welcoming... I'm completely at loss with this...

I've tried changing the lamp bulb of my condenser head but that didn't solve anything. On the contrary it brings another puzzle as no two 150w bulb I bought give the same illumination. And the difference is huge! I have three bulbs and there are at least 1 or 2 stop (and up to 3) difference from one another... But that issue should make another thread, and I picked up the middle one.

If anyone has a clue here's the details:
Enlarger is a Durst M805 with a condenser head and a new 150w Dr. Ficher bulb.
Film is TX400 in HC110B for 6min (or 5.5 depending on the camera used)
Chemistry is fresh
Contact print paper is Ilford RC glossy
Printing paper is foma FB MG classic 24x30cm

You're help is much appreciated as I am starting to wonder if I should start messing with my developing time or developer or something else...

Thanks!
Vania

 

[Rich Ullsmith]

Contact print paper is Ilford, print paper is Foma. Me thinks this has something to do with it.

I find about 1/2 grade drop in contrast from a contact to a print. That is using the same paper for both.

 

[Alex Muir]

When highlights are difficult to print, it can point to over developed negatives. You could try your HC110 at a higher dilution as this would give scope for reducing development time without it becoming too short. I use HC110, but seldom use it at dilution B. Nowadays, I dilute it 1+49, and use times for dilution E. This was mentioned in previous threads here.
Alex.

 

[cliveh]

Hi everyone,

I'm facing a very odd problem. My 6X6 contact prints are very well balanced in term of contrast. Printed with a grade 2 filter there's details everywhere in the shadows and the highlights. Now when I print the contrast gets blown away. I have to print with a grade 0 filter AND burn for at least 2 or 3 stops more the highlights to get some details out of it (but it's there). Shadows are fine.
Thanks!
Vania

Why do you have to print with a grade 0 filter and have to burn in? Why not print as you do when contact printing?

 

[Loren Sattler]

I would try enlarging some prints with the same RC paper and see what you get. Do you use your enlarger (with #2 contrast filter) as your light source for contact printing? Also, any chance there is an issue with the contrast filters? Let us know how the RC paper works.

 

[tih]

There are potentially several things going on here (including contrast differences between the two types of paper), but in general, all other things being equal, contact printing would be like using a diffusion enlarger in terms of contrast (ie lower contrast than a condenser head). The difference shouldn't usually be more than about a grade (often less), but there are other variables in your system.

One of these other variables is negative density; high density negatives get a larger contrast increase with condenser enlargers. If you look at the thread in this forum titled "0.6 -- standard contrast?", you'll find reproductions of research information suggesting about one and a half grades as a typical difference.

 

[Anadred]

Fomabrom needs more exposure than Ilford RC. Plus Fomabrom is chlorobromide paper that is more sensible to different types of paper developers.

 

[MDR]

The bigger the enlargement the higher the contrast as you will loose some of the midtones due to the enlargment. A contact print will always have better highlight and shadow details than an enlargment. But not this extreme. Also different paper will react differently to Multigrade filters. Fomatone isn't overly contrasty though. Fomatone is a native grade 2 paper so try it without filter and see what you'll get some burning in will be required.

 

[Vania]

Thanks for the answers. So far I've tried to print on the rc paper which allows me to print with a grade 1 filter instead of 0 and get good gradation. But it is still very contrasty. Very interesting notion tih, but if one would think that the neg are overdeveloped/agitated somehow, this is where it's odd. The negs are actually not dense and on occasion rather thin, but with just enough details in the shadows. And they print fast enough (around 12 sec with the rc and 18sec with the fomatone @ f/11 for a 22x22cm print of a 6x6 neg with a 150w condenser head) to confirm that they are not too dense... I'll have to try a -15% dev anyhow just to be sure, but it feels like I'm missing something, if someone have additional thought...

 

[Xmas]

Thanks for the answers. So far I've tried to print on the rc paper which allows me to print with a grade 1 filter instead of 0 and get good gradation. But it is still very contrasty. Very interesting notion tih, but if one would think that the neg are overdeveloped/agitated somehow, this is where it's odd. The negs are actually not dense and on occasion rather thin, but with just enough details in the shadows. And they print fast enough (around 12 sec with the rc and 18sec with the fomatone @ f/11 for a 22x22cm print of a 6x6 neg with a 150w condenser head) to confirm that they are not too dense... I'll have to try a -15% dev anyhow just to be sure, but it feels like I'm missing something, if someone have additional thought...

In a distant galaxy aeons ago (to some) there were two development times published for each developer film combination.

Condenser
Diffusion

If you try a plastic plate ground matt one side in condenser assembly for lamp on for 30 seconds - so you dont melt it, you might gain a grade or two. Then you could get a plate in heat resistant glass made up by local glasier.

One of the '60s 35mm enlargers had a semi condenser arrangement with one surface matt to minimise grain...

You may need to alter your development time otherwise, per the introduction.

The norm was to try and keep most negs on grade 2, when multigrade (VC) paper was not as popular, otherwise you needed boxes for each paper type/surface, and you could not do split grade...

 

[Christopher Walrath]

I'm thinking along the lines of the Foma being slower. Saw the same thing when I upgraded from Arista to Orient Seagull papers myself. Well, my change was less exposure. You just need to print differently when using a new paper with different characteristics. When you find your base times you can do the math and adjustments should be easier to make.

 

[Vania]

No, no, it's not a question of print density, but contrast. The paper actually seems fast enough to me.

 

[Vania]

Here's another way to look at it :
Sirius Glass wrote here ((there was a url link here which no longer exists)) :How about what Ansel Adams and others wrote: Start with grade 2 and get the exposure for the high lights. If the blacks are to blocked go to grades 00, 0, or 1. If the blacks are too weak move progressively to 3, 4, and 5 as necessary.
I have very bright highlights so if I proceed this way my midtones would be near black and shadows would be lost. So I use a grade 0, but still have to print for the midtones and then burn the highlights.
What to think of this?

 

[Simon R Galley]

And the Multigrade filters are ILFORD ? and how old are they ?

Simon ILFORD Photo / HARMAN technology Limited :

 

[Vania]

Ilford yes and rater new, less than 5 years I'd say...


Vania

 

[Alex Muir]

I print Tri-X 6x6 to a similar size on a condenser enlarger with a 75W lamp. I use Ilford MG RC with their filters, and I get about 7.5 secs at f11. If you get 12secs with the 150W lamp, perhaps the negs are a bit dense?
Alex

 

[Vania]

That's good info thanks!


Vania

 

[Vania]

That was my original thinking but when I see how perfectly balanced the contact prints are it gets me all confused... Well I'll try lowering my dev time and see from there.


Vania

 

[Jim Noel]

When images pass through glass, the lens, contrast is altered. Also every paper responds differently. If you really want to determine the difference between the projected image and a contact prit, use the same paper for both.

 

[Vania]

Yes as I mentioned I did that but still find a huge contrast difference even though I can use a higher grade filter than the other paper.


Vania

 

[tih]

Very interesting notion tih, but if one would think that the neg are overdeveloped/agitated somehow, this is where it's odd. The negs are actually not dense and on occasion rather thin, but with just enough details in the shadows.

All right, then that's probably not the problem. See, the reason why condenser enlargers create higher contrast is that they focus their light source through the negative, so that the light is directional; it is streaming vertically down through then negative, then through the lens, and onto the baseboard. With a diffuser enlarger, the light is bouncing all over the place. Now, the light gets scattered by the silver in the negative, and where there's a lot of silver, that is, where the negative is dense, there will be more scattering than where there's little. For a diffuser enlarger, this doesn't make much difference, since the light is coming in from a lot of directions already, and while some of the scattered light will be light that would have hit the lens, and now doesn't, there will be other light that wouldn't have, but does. In a condenser enlarger, on the other hand, the light is focused, collimated, so it's streaming vertically through the negative to the lens. Light scattered by the silver is lost. This means that dense areas of the negative will be darker on the baseboard than with a diffuser enlarger, and higher contrast will ensue.

Now, if your negatives are not excessively dense, they must be too hard. To develop for softer negatives, use shorter times, or higher dilutions. You're using HC-110, which is known to be very well suited to contrast adjustment by dilution. If you develop for the same length of time, but vary the dilution of the HC-110 concentrate, you'll get different constrast negatives. I do not have HC-110 experience myself, but I've heard it claimed that as a rule of thumb, if you start with 1:30, then 1:40 with the same development time will be about a grade softer, 1:50 another grade softer. and 1:20 a grade harder than what you started with. Remember, though: if you dilute more to soften your negatives, you'll need to expose a little more to maintain shadow detail.

I've been reading old books on this topic lately (Adams, Gassan, Henry, Mees), and it seems to be generally accepted that you need to expose sufficiently to keep your lowest textured shadows above the toe of the film characteristic curve, and then tune your development to give a level of contrast suitable for printing on grade 2 with the enlarger you use. An important reason for keeping the base exposure down to just enough to keep the lowest textured shadows above the toe of the film is that over-exposing gives coarser grain.

 

[Vania]

Thanks again! Very informative tih. I cut down my development time by 20% and got better contrast (1.5-2), but with longer printing time... go figure... Still the difference in contrast with the contact print is huge and difficult to understand, but at least I get good printable negs, as I like them a bit contrasty anyways, and shadows details are still there.

 

[tih]

Thanks again! Very informative tih. I cut down my development time by 20% and got better contrast (1.5-2), but with longer printing time... go figure... Still the difference in contrast with the contact print is huge and difficult to understand, but at least I get good printable negs, as I like them a bit contrasty anyways, and shadows details are still there.

Yeah, you're still going to see the same difference between contact printing and enlargement: that's a function of your enlarger. Glad to hear you're getting more printable negatives!