Dark Test Strips/Prints

Derek m · Mar 13, 2018

I'm using an El-Nikkor 50mm 2.8 with the aperture set at 5.6, and can't go beyond a 3 second exposure time. 4 seconds is almost completely black. Stopping the lens down helps, but I've read that the optimum aperture usually is two stops down from wide open. So am I doing something wrong?

I've only been making 5x7" prints at the moment. Haven't been in a darkroom since '00, but I recall being able to get longer exposure times, although I suppose the lens could have been stopped down all the way.

I've read that you can use an ND filter, but will that affect the use of regular contrast filters?

Carriage · Mar 14, 2018

I think the solution is to just stop down. I usually do 5x7 at f8 or f11 but I've never tried to compare to see if there are sharpness issues at smaller apertures. It may not be that big a deal given the print size anyway.

jimjm · Mar 14, 2018

Depends on your enlarger and the intensity of the bulb, but I usually also have to stop down to f8 or f11 to expose 5x7 prints for more than 5 seconds. This is for a "white light" exposure without any filtration added. Given the low magnification at that size, you probably wouldn't see any problems stopping down to 16 or 22 either. Density of the negative will also impact the exposure time.

Once you start enlarging to 8x10 or bigger, exposure times will increase significantly. For B&W I have a dichroic head which uses a combination of yellow and magenta filters to achieve a desired contrast. This extends the exposure time longer than using a single contrast filter, but also gives ample time if you need to do dodging and burning.

MattKing · Mar 14, 2018

While the optimum aperture may be two stops down, the diffraction effects that you will encounter at smaller apertures are fairly minor, and will essentially be invisible at the small magnifications involved in a 5x7 print.
Modern, high quality enlarging lenses are just that - high quality - at all apertures.
If you were printing 16x20 prints, it would be a little different (but still pretty high quality).
You would see more contribution from switching to glass carriers from glass-less.
And by the way, an ND filter will work well with the contrast filters.

Derek m · Mar 14, 2018

Ok that's a relief. My 23ciii xl has a 75w bulb in it. I'll make some 8x10's this weekend and see how they turn out. Thanks everyone.

RalphLambrecht · Mar 14, 2018

Derek m said:
I'm using an El-Nikkor 50mm 2.8 with the aperture set at 5.6, and can't go beyond a 3 second exposure time. 4 seconds is almost completely black. Stopping the lens down helps, but I've read that the optimum aperture usually is two stops down from wide open. So am I doing something wrong?

I've only been making 5x7" prints at the moment. Haven't been in a darkroom since '00, but I recall being able to get longer exposure times, although I suppose the lens could have been stopped down all the way.

I've read that you can use an ND filter, but will that affect the use of regular contrast filters?

aND fiter will not affect your contrast filters but, you must have a different problem; too bright of a bulb perhaps?

ic-racer · Mar 14, 2018

Use f11

Ponysoldier · Mar 14, 2018

I have to use a .3 (1 stop) ND filter to keep my exposure times in the 8-12 second range at the f8/11 "sweet-spot" with my 150mm El Nikkor. This because I switched to a Modern Enlarging Lamps LED head (not the VC Model) on my Omega D5. I have to agree with Matt that - at 5x7 - you are not likely to see the effect of stopping down. The ND acrylic sheets for insertion in the light path are inexpensive, easily cut to size and, in my experience, don't alter the color temperature for VC filters.
Joel

Derek m · Mar 14, 2018

Ralph - It's the PH140 75w bulb, which is listed online as the correct bulb.

I am going to stop down as has been mentioned, and go with an ND filter if I have to when printing larger. Thanks everyone.

etn · Mar 14, 2018

Apologies if I am asking an obvious question (but it was not clear reading your original post and I am not familiar with your enlarger):
Are you using any kind of filtering (such as multigrade filters) ?

Derek m · Mar 14, 2018

No worries, I forgot to mention that actually. I have an Ilford set of filters and have been using a #2 on Ilford multigrade iv paper.

pentaxuser · Mar 14, 2018

Derek m I have the same lens and bulb, do 5x7 almost exclusively but find that with Ilford filters I get about 7-9 secs at f8 so at f11 my times are in the region of 14 -18 secs which is enough for normal dodging. At f16 where the 2.8 El Nikkor stops I am into really long exposure times.

pentaxuser

glbeas · Mar 14, 2018

Just to be on the safe side have you taken the lens out and look through it while stopping down to verify the aperture is actually working?
Also on the off chance some lenses have a focus lever that pops the aperture all the way open independent of your click stop ring, be sure thats not an overlooked option.
If you are doing small prints a majority of the time you might want to look for a slower speed paper.

Derek m · Mar 14, 2018

pentaxuser - I appreciate the details. I will stop down and compare this weekend.

glbeas - The aperture is working fine. Thank you for the tip. Right now I'm just printing 5x7's until I get comfortable with being back in the darkroom so as to not waste paper.

cornflower2 · Mar 17, 2018

I'd suggest you use f8 with your lens (which will let you check the projected grain for sharp focus if you need to, and will also probably provide the sharpest lens rendition) and add one, two, three or more (how ever many you need) 0.3 ND gel filters to your filter drawer (I normally keep two of them stapled together in one corner for use in my Focomat IIc filter drawer with a 150W Photocrescenta lamp). These will not affect the way your multi-contrast gels work and you can always slide the filter drawer out for brighter viewing or focusing. Another thing to check is your developer. If it is too concentrated or working at a high temperature, or if you are developing for too long, then it may give you a print which is too heavily developed and thus too dark.

Sirius Glass · Mar 17, 2018

I typically use f/8 or f/11. I found that f/5.6 got too dark way too fast.

removed account4 · Mar 17, 2018

hi derek m

dimmer bulb sometimes helps, and developer that is a little more dilute sometimes helps, aristo used
to sell a riostat which was useful too...
one thing that helped me when i had extremely short exposure times was to devlop + expose my film
differently. i realized that a little more exposure and sometimes a little more development gave my
negatives enough meat on the bone+ SNAP so i had longer / better exposure times. thin negatives
are great for the electronic gizmos but when it comes to darkroom printing ( enlarging, or contact prints )
extra density is the photographer's best friend...

best of luck with your darkroom work !
john

Fritzthecat · Mar 17, 2018

Everyone is overlooking another reason, thin negatives. Do a personal ISO test to find the exposure that gives you negatives that all but print themselves. I personally expose negatives that allow between 20 and 30 second print exposures for 8x10's. That gives me leeway for any B&D work.

Sirius Glass · Mar 17, 2018

jnanian said:
hi derek m

dimmer bulb sometimes helps, and developer that is a little more dilute sometimes helps, aristo used
to sell a riostat which was useful too...
one thing that helped me when i had extremely short exposure times was to devlop + expose my film
differently. i realized that a little more exposure and sometimes a little more development gave my
negatives enough meat on the bone+ SNAP so i had longer / better exposure times. thin negatives
are great for the electronic gizmos but when it comes to darkroom printing ( enlarging, or contact prints )
extra density is the photographer's best friend...

best of luck with your darkroom work !
john

+1

DWThomas · Mar 17, 2018

For printing at that size (or 5x5 inches from my 6x6 cm negatives) I keep a two stop ND filter on hand. I managed to equip myself with 50, 80 and 105mm lenses that all take the same filter size, just in case. Compared with what I think I remember after a four decade break from printing, I think many of today's enlarging papers are considerably faster than at the time many enlargers were designed.

Derek m · Mar 18, 2018

I'll be picking up some ND filters to have on hand, and do some testing with exposure on my next roll.

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