A great way of making a blocker is to take that thick art paper, cut it to fit into one of the plastic envelopes that the photo paper comes in, and place it in there.
Originally Posted by edcculus
It makes it such that the blocker is malleable, so that you can bend it, which helps when burning portions of the print in.
It also makes it light and nimble, and when it gets dirty for whatever reason, you can just wipe it off.
"Often moments come looking for us". - Robert Frank
"Make good art!" - Neil Gaiman
"...the heart and mind are the true lens of the camera". - Yousuf Karsh
Oh, great idea!
One quick question about both Thomas's and Smieglitz's methods. I have my process dialed in a little better. I know for a 35mm negative being printed at 8X10 with a medium aperture (lets say f8), I'm going to require somewhere in the neighborhood of a 30-40 second exposure depending on the negative, crop etc. Unless I have a negative thats really bad, I can rule out any exposure lower than 20 seconds. When I do smaller formats, I even dial down the aperture so I can keep my exposure in the +20 second range. Short exposures seem really hard to control to me, plus its easier to dodge/burn at longer times.
With the count down method, I suppose I could make the portions larger, and just stop before I get all the way down to the lowest exposure. With the count up method, would I just expose the entire sheet at the lowest exposure I want to start with (say 16s), then add from there (+4, +5, +7 etc?)?
Last edited by edcculus; 05-21-2013 at 09:35 AM. Click to view previous post history.
Originally Posted by Thomas Bertilsson
Another thing to note about light leaking through the test print blocker - in addition to causing errors by darkening the test strips, it will also cause contrast errors, making it virtually impossible to evaluate contrast in the test print. The art paper lets some light through, but as it is reasonably opaque, thick, textured etc. it is totally diffusing the image so the light getting through essentially becomes non-image forming exposure (ie fog). This can have a significant contrast reduction effect on the test print.
I'm back from my darkroom. Here are the results.
I put the art paper into Ilford's black bag and used that as light blocker. I set aperture at f8, with #2-1/2 filter, set exposure time at 8 sec. I divided test paper, before exposing it, into 6 segments using felt marker. I developed test sheet for 1 min in Ilford's Multigrade set at 1+9 dilution. The test sheet come out as expected.
Than I chose 24 sec for the final print, as this strip looked best to my eyes, without changing anything on the enlarger. No, the print didn't mach the test strip. It was to light again.
I newer imagined that all this printing would be so difficult. But on a positive side I'm not quitter and I will not give up trying.
Too bad you can't post some scans of the test print and final print.
You are right not to give up. This is not supposed to be difficult. Something is clearly wrong.
1) What kind of timer do you have? When the enlarger light is on during the final print exposure do you notice it getting dimmer/brighter during the exposure? Since your test intervals were 8 seconds, and you liked the strip that was exposed three times - try giving 3 exposures of 8 seconds for the final print instead of one 24 second exposure. See if that changes anything.
2) Is your safelight fogging the test print (since it takes longer to make the test print)?
3) Is your enlarger providing even illumination? Try doing the test print in the opposite direction and see if you get the same results.
4) When you examine the final print, in addition to being lighter overall than the test strip, is the contrast different?
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the timer I'm using is GraLab digital. I didn't notice any changes in light brightness. I'll try 3x8sec exposure you suggested. I have tested the safe lights by putting coin on top of the paper and kipping it under the lights for 5 min. There is no fogging as far as I can see. I'm not sure about contrast as the print is so light it's hard to say for sure.
Best of luck with 3x8 secs as opposed to 24 but the difference between the exposure using these two methods is fairly marginal and unless "lighter" means just about discernibly lighter I fear that this will not be the solution. I think by lighter you mean nowhere near the same look which suggests that the difference is considerable.
There has to be something else at work here. I take it that you are testing without any filtration and likewise are exposing the final print without filtration. I also take it that you are not accidentally touching the enlarger lens and altering the aperture nor focusing again for the final print at say a bigger aperture and forgetting to restore the aperture to the original test strip setting
I appreciate this sounds as if I am treating you as almost educationally subnormal and this is not my intention but there has to be something you are changing.
Try doing another test strip writing down all your steps carefully and then literally ticking off each step as you perform the action and doing the same when you do the final print.
I'm making test strips using #2.5 filter and I also use same filter for the print. I don't really mind the educational treatment as I need to cover all the possibilities.
I agree the 3x8 is probably not a meaningful experiment at this point particularly since SloboM clarified he's using a digital timer. My original line of reasoning was that with some older worn out analog sweep timers I've actually seen the light output look pretty unstable. I thought perhaps there was something going on there.
Regarding aperture I think SloboM indicated he was using f/8 for the test and final print. Correct me if I'm wrong on that, SloboM.
If all other variables are equal and the difference is that huge I'd have to go back to my original suggestion that SloboM is doing something incorrectly in the test print, which is leading him to choose an exposure time that was not in fact the exposure time for that strip. For example you choose the strip you thought was 24s when in fact it was 32s, something like that.
I suggest trying a few final prints after the test print. If your test print was in 8s increments and you think the 24s time was right, make a few final prints. One at 24s, one at 32s, one at 40s. See if any of the longer ones look right, and if the contrast is different than the test print. That could help diagnose the problem.
Last edited by Michael R 1974; 05-21-2013 at 02:23 PM. Click to view previous post history.
Yes you are right, the aperture is f8 in both instances. I'll try different exposure times as you suggested Michael.
Last edited by SloboM; 05-21-2013 at 05:24 PM. Click to view previous post history.