View Full Version : Contact printing: condenser v. bare bulb

Erik Ryberg
12-Jan-1999, 00:03
Hello. Recently I contact printed an 8x10 negative under a bare 15 watt frosted bulb permanently fixed to my darkroom aka closet's ceiling. While washing the prints I thought that they looked a little blurry, specifically in the weave of a shirt of a person in the photo. The image of the person is less than an inch wide but in past prints I could clearly make out the weave. I thought perhaps the glass in my contact frame was dirty, cleaned it, and tried again. Same thing. So I figured I was making it up and quickly made another p rint, this time as I had in the past, using my enlarger as the light source with the light coming through both the condensers and the lens. And I got a sharper image! The weave of the shirt clearly showed. Does anyone here know why I am getting better images under the enlarger light? Did not E. Weston use a bare bulb to make his prints? Is there something I can d o to improve my bare-bulb technique so I can get rid of my enlarger once and for all, which has been the whole point of this endeavor in the first place? I posted this story in rec.photo.darkroom and got the answer that the Callier ef fect is making more contrast in my image and this is why I am getting a better i mage under the enlarger. I don't believe it. If that were so nobody would use diffusion enlargers. The negative has plenty of contrast for silver gel contact printing and shows plenty of contrast when printed under the bare bulb. But it is not as sharp. I'm using Agfa Multicontrast Classic FB paper. I realize the color of light may be slightly different from the enlarger bulb and the bare bulb, but it can't be that far apart and the overall contrast between prints made with the two differ ent bulbs looks to be the same to me. Other respondents to the rec.photo post said they had experienced the same thing and suggested they now only use enlargers as light sources. Thanks for bearing with me on this long post.

Sean Billy Bob Boy yates
12-Jan-1999, 00:31
Mr. Ryberg,

It is of course hard to tell what's going on with your set-up, not being able to see the results. Maybe if you held the print a little closer to the modem? Seriously though, try it again. Deliberatley try to make blurry prints with negatives of large uniform tones, sky, sand, snow, whatever. See if it occurs with different negatives, etc. Could it be the dreaded Newton's Rings? The Van Allen Belt? I don't know. Is the enlarger "unfocused" - casting a negative carrier shadow with soft or hard - focused edges? Would that make a difference?

I once made 76+ prints of a group shot, (1 for each person and some extras, just in case) using a Besseler 23 of ancient vintage on Ilford MGIV RC Pearl. Other than complaining about dust and wondering about my mental faculties, I had no problems. Now however, I have switched to Azo.

With Azo I use a 300watt bulb in an appropriately wired fixture with the Gralab between the outlet and the lamp. The distance is maybe 6 - 8 feet and times are running 8 - 12 seconds. Although I have not tested to compare, kind of hard considering Azo's Sloooooow speed, I have not had any "blurry" prints.

The only time I got Newton's rings was when I used RC Glossy paper for a "client" and used the enlarger. Sorry I can't be of more assistance. I haven't encountered this, yet, thank God!

Sean Billy Bob Boy yates
12-Jan-1999, 00:43
Forgot to add...

Yes, Edward (and Cole when re-printing his dad's work), both used bare bulbs and a clothes pin. Michael A. Smith uses a bare bulb.

I haven't been able to afford one of those great old contact print frames Burke & James & the others used to make but I don't imagine there are any condensors in there. Certainly no room to focus the light....

Alan Gibson
12-Jan-1999, 07:46
The problem is probably due to the size of the light source. 'Size' measured as an angle from the contact frame. If the negative emulsion is not in perfect contact with the photo paper (and it won't be, no matter how good the contact frame) then a non-point light source will image different parts of the negative on to one part of the paper.

A enlarger, with a lens, is pretty much a point light source. A bare bulb, especially frosted, isn't. In addition, a bare bulb will probably bounce light around the walls of the darkroom, so light hits the photo paper from practically all directions.

Charles Matter
12-Jan-1999, 10:32
As far as I can tell from extensive readings of the "Daybooks" Weston made most of his 8x10 contacts on Azo with his print frame in sunlight. Azo is POP (printing out parer). Considering that the sun and a condenser are both pretty much point sources..a bare bulb would probably need to be focused a bit more. Try using a reflector with the bulb..or even a reflector spot. Beware of printing on the bulb coming thru on long exposures

Sean Billy Bob Boy yates
13-Jan-1999, 03:27
Mr. Matter,

I would suggest a closer reading of the Daybooks, or at least peruse Kodak's catalog. Azo is not now, nor has it ever been in it's 100 year history a POP. It requires a developer like Dektol or Amidol or Selectol or any other such. It is slow, too slow to use an enlarger as a light source, but no slow enough to take outside and print with the sun. Weston's negatives would've had to have been beyond bullet proof for that. Michael A. Smith wrote an article on printing with Azo for View Camera magazine a while back, I imagine you could still get the issue or a photocopy of the article.

On page 236 of his Daybooks, Volume II, Weston says, (01/27/32) "I have also completed a tremendous task, approached with the greatest enthusiasm: that of reprinting my entire New York exhibit on a new paper. A demonstrator for 'Velour Black' sent me a trial package: it is so much superior to the paper I had been using, that I changed without hesitation."

In "Darkroom 2 (ISBN 091281022X) Cole Weston describes in great detail about how he and his father printe(ed) Edward's negatives. "Early in his career, Dad used platinum paper. As he matured as an artist, he grew to feel platinum was too 'soft' for his work, and he began printing on silver papers. The early silver papers were also relatively 'soft' compared to most of the ones today (1978). Among those that Dad used were Velox, Apex, Convira, Defender Velour Black and haloid. Dad loved haloid, which was manufactured by a company that later became Xerox. The paper had a wonderful warm tonality. Dad used to say it had a three-dimensional quality."

I know, none of this has added to Erik's understanding of his original posting. You were kidding around about the printing on the bulb, weren't you?

Lot Wouda
13-Jan-1999, 07:32
You print under a bulb fixed to a darkroom aka closet's ceiling. I don't know what aka means, but I imagine printing like this can give all kinds of reflections on the contactframe, which do not occur under the enlarger. Did you look up and around from the spot where your contactframe is? The bulb exposure is indeed a kind of diffuser exposure and thus it is evident that prints are not that sharp: light can come from all directions. I can imagine there is still a Callier-effect, although in contact-printing this effect is less than when enlarging your prints from a condensor - in my experience. Try building a tunnel around the bulb. I my opinion it is no non-sense to consider a possible print on the bulb.

Sean Billy Bob Boy yates
13-Jan-1999, 10:15
An object casts a shaper, more well defined shadow, the closer it is to the surface it's casting that shadow upon. The farther away, the softer, more poorly defined that shadow is. The closer to the light source the shadow forming object is, the less sharp, more diffuse the shadow is. A car on the street at noon on a cloudless day casts a much sharper shadow than a plane flying over head which casts a sharper shadow than say, the moon, or Venus.

Assuming the light bulb is 2 - 3 feet from the negative/paper, why would you expect the very small printing on a frosted bulb to register on the print? Dust on the negative shows up in an enlargement, but not the printing on the bulb in the enlarger lamp house. I have yet to encounter an article on contact printing that mentions the threat of "G.E. 100 Watt" showing up on the print.

Charles Matter
25-Feb-1999, 10:51
Disregard my previous answer. Azo is not (of course) a POP, and never has been..and Weston used many different types of paper (including AZO). The point I was trying to make (even tho I was apparently thinking somewhere else) was simply that Weston used a single overhead bulb in his dark room for much of his work. I have never noticed any difference between a single bulb and a condenser enlarger source for contact printing except in exposure time. If the negative is sharp, and in good contact with the paper, and your glass is clean..the image will be sharp regardless of the light source. AZO is a very slow paper..and a 15w bulb overhead (or even up close ) will require a lot of exposure..especially with any kind of negative density. You'll be happier with a bright condenser source.

Apologies for any confusion, and/or ruffled feathers CDM