very short proof and enlargement times?

[brian steinberger]

I was practicing printing last night and was suprised when my proof times for 4 4x5 tmax negagatives were about 2-3 seconds on Kodak Polymax RC paper. Then I enlarged one to about 7x10 or so, and the correct exposure time was 2 seconds. This seems very short. All the books I'm reading tell you to run test strips for about 3-5 seconds for each section of exposure. I'm stopping the lens down to f/11. I'm diluting my dektol 1:3 for two minutes. I'm just wondering if this is normal. Any thoughts one what I might be doing wrong.

[Jerry Flynn]

Is f/11 the normal stop you use at that elevation? With a Zone VI cold light source (V54), I am usually stopped down to f/22 for 11X14.

[brian steinberger]

by the way, I'm using a Beseler 45M enlarger, which I believe is a condenser head.

[Oren Grad]

Brian, when I make small enlargements from 4x5 with my LPL4500II, I usually need to use the built-in 2-stop netural density filter to keep the exposure times from being too short at my working aperture of f/8. So long as your negatives are dense enough to give you prints with a good tonal scale, don't hesitate to add neutral density in the enlarger head to allow working at the optimal aperture for your enlarging lens with convenient exposure times.

[Brian Ellis]

It's hard to say with the proofs because they presumably were contact proofs and so the exposure time will depend to some extent on the distance between the lens and the paper. If you had the lens very close then a short time would result (and wouldn't be a problem because you won't be dodging, burning, etc. contact proofs).

But 2 seconds is clearly too short for the enlargement. Either the light itself is wrong (too bright) or it's something related to the condensers would be my guess. The optimum aperture for most enlarger lenses is one to two stops from wide open. If you have an F5.6 lens then F11 or something very close to it would be the desired aperture so that doesn't sound like the source of the problem.

I have a Beseler MXT but with a cold light head so I've never used condensers. However, on the MXT there is a little gadget that with condensers tells you the correct position for the upper bellows depending on the film format being used. Do you have something like that and do you have the bellows in the propler position for 4x5? I don't know whether having it in the wrong position would lead to excessively short exposure times but it certainly is desirable to have it in the correct position regardless, assuming your enlarger is like the MXT.

[John Cook]

You are correct that your exposure is way too short for that set-up.

Several things could be causes. Two things come to mind. There are probably more.

Check the position of the condensers. It has been too many years since I owned a 4x5 Beseler, so I don't rememner. But you may be set up for 35mm if the condensers are variable.

Check the lightbulb. That sort of head usually has a standard lightbulb socket. If you bought the enlarger used, some twit may have installed a high-wattage bulb from a table lamp instead of a standard enlarger bulb.

Read your enlarger owner's manual. It probably calls for a lamp such as:

http://www.bhphotovideo.com/bnh/controller/home?O=productlist&A=details&Q=&sku=20189&is=REG&addedTroughType=categoryNavigation

[brian steinberger]

Does anyone know what the standard bulb for the 45M is? Wattage and Volts? I just looked at the bulb in my enlarger. There is a 150W, 125V bulb in there now. Is that too much? I did by it used.

[Brian C. Miller]

150W?? Wow! My Omega has a 75W in it.

[Donald Qualls]

Exposure time also depends on enlargement factor, of course, but I've found that on RC paper (typically a little faster than fiber paper), at f/18 with an enlargement factor of around 4x, I need an average of about 20-25 seconds with my soft filter, and 10 to 25 seconds with the hard filter, in split filter printing (I'm using a Zone VI cold light in an Omega D2). Your 2x enlargement would call for 1/4 that exposure with the same light, negative density, and lens opening on the same paper. Using a slightly lower head setting, same lens opening, and empty 4x5 carrier without filters, I've been contact printing on the same paper at 8 to 16 seconds, depending on the negatives (much of my medium format and smaller is unmetered, exposed by Sunny 16, and so varies up to one stop from ideal exposure).

First thing I'd try is stopping down to at least f/16, though going smaller than that might be counterproductive (depending on your demands for print sharpness; diffraction will steal some sharpness even from f/11, but the loss won't be significant until you pass f/16). Beyond that, it's certainly possible to add some neutral density (if you only have printing contrast filters, you can add a #1 filter to a #4 to approximate adding neutral density, or similar, though you might need to adjust the grade of the stronger filter); ideally, you'd want to be running around 20-30 seconds for single filter or graded paper, or in that range for each filter exposure if split filtering; shorter than that makes it very hard to dodge if needed and also means burning in exposures will be uncomfortably short. With little enlargement, you might also find it acceptable to stop down as far as f/32 (my 135 mm lens will go to f/45, though I'm not certain where I'd use such a tiny opening -- perhaps if I were tilting the easel to correct perspective or similar trickery). If you're using a tungsten light, reducing the bulb wattage is another very good way to extend printing time (and leaves the option to go back to the brighter bulb when you want to do tight crops or very large prints).

[Richard Schlesinger]

I'm using an Aristo head with a V54 tube in my Beseler 45M enlarger; I get extremely short times as you describe. So. I purchased from Aristo their rheostat for the cold light so I can always print with my 135mm Rodagon (or whichever lens) stopped down one or two stops - no more - from wide open. If the time is too short I just dim the light (there is a dial with numbers etc. so I have calibrated, one stop, two stops less etc.). This makes a really nice arrangement - plenty of light for large prints, less for smaller. Always the optimal aperture on the enlarging lens.

[ronald moravec]

75 watt is fine for 4x5, in fact still a little much for 8x10 prints. A wall switch dimmer in the line between the timer and enlarger will dim the bulb adequately. The cadillac option is the Aristo dimmer for their cold light heads. This is a beautifully crafted dimmer. It looks like some expensive electronic device made 50 years ago and works very well. You will get up to 3 1/2 stops less light completely viriable. You can also add a zone 3 or 4 fogged neg in the filter slot.

Any diffusion device like tracing paper or plexiglas will change the character of the enlarger light making it more diffused.

Wire in the wall dimmer at your own risk. Put it in a wall box mounted to a board.