Cold light or not.......... that is the question

Flotsam said:

There has been mention of differences in the quality of condensor systems. I know that the function of a condensor system is to concentrate the light from the bulb evenly over the negative in it's carrier but beyond that, what characteristics would separate a "good" condensor head from a "not so good" condensor head?

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As Donald stated below even distribution of light this is only part of the picture. Directed light means directed from the bulb right through the lens down to the baseboard. With directed light you are concerned about the light taking the right direction: Into the back of the enlarger lens and through its aperture. Diffuse light acts more like a shotgun here, sending the light in all directions thereby passing enough through the lens. A condenser-set must have the right focal length to send its light through the aperture of the enlarging-lens instead of bouncing it against the mount or the bellows and the right image circle to illuminate the respective negative.

Not quite as "good" systems and (I'd better said "less collimated") work with more diffusion, white domes, closer/bigger opal-lamps to achieve even illumination with universal condensers, less collimation, less sharp grain, less obvious scratches/dust. Leitz Focomats or my former Dunco 66IISW are examples for such in-between constructions.

The increase in contrast and apparently sharp grain (after adjusting contrast) when stepping form a Dunco with an universal condenser for 6x6 in a white mixing-box to a Durst L54 with dedicated condenser-sets for every focal length, all black inside, and a lamp quite distant from the negative stage was astonishing at least to the beginner I was at that time.

My personal solution to the question is simple: have both and use them as subject matter and technique suggest. Used enlargers are to cheap these days to restrict myself.

best

Stefan

Hi doug,
I tried this when I wanted a cold light head for my d5 but didn't have the funds to do so at the time( I finally got one from that well known auction site). Go to a plastic supply store and purchase a piece of translucent acrylic I tried a piece of 1/4" but an 1/8th would be better as it wouldn't absorb as much light. Get them to cut it just slightly larger than the condensors. Then when you get it home trace around the housing (condensor) and remove the circle of protective paper and remove the paper on the otherside then place this under the condensor and above the neg carrier. You may have to use electrical tape to mask off some of the stray light.
Try making a print with the plastic in place.the light from the condensors will be even above the plastic which will then be diffused before it passes through the neg. if it works and print times aren't to long you can cut the plastic to fit permanently under the condensors. The price of the acrylic shold only be a couple of bucks.
best regards
Andy tymon

I had an interesting experience in my darkroom today. If any remember I had a negative I'd shot at Jekyll Island this spring that looked good scanned and tweaked but when I tried to print it the mid tones just muddied up and the detail got lost. I was using a dichroic head and Polycontrast RC paper.
Well I just finally got my hands on a condensor head for my Beseler and also got some Ilford Warmtone fiberbase vc paper. With the jump in contrast I got from the condensor I put a no. 1 filter under the lens and the print came out looking nearly like what I posted in the gallery. I'd scan it to show what I got but it's 11x14, too big for the scanner bed. Any comments on this?

Gary,

Am I understanding you to say that the local contrast increased with the condensor light source? The change could be due to the paper. It could be due to the condenser.

Overall contrast increased, as expected. What was not so expected was the better separation of the midtones when I used a lower contrast. Is this an increase in local contrast? I know the details are a lot sharper looking and better defined.

Gary,

In my experience using both diffusion and condenser enlargers, the condenser enlargers do give better local contrast. The reason that this happens, in my opinion, is that the condensor collimates the light beams and they pass through the negative much more perpendicularly. This can not but give better delineation to the differing but adjacent film densities.

When I started using a condenser enlarger about 4 months ago, it was almost an "ah hah" experience. Almost as if suddenly the reason for all of the good prints that I had seen and failed to produce had been made apparent.

I am pleased that you found that the results were what you wanted.

In order to avoid Callier Effect is advisable to use diffused light. This is something well noticeable with condensers (colimated light). See examples in the book Fine Print by Fred Picker.

sergio caetano said:

In order to avoid Callier Effect is advisable to use diffused light. This is something well noticeable with condensers (colimated light). See examples in the book Fine Print by Fred Picker.

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Sergio, The so called Callier effect is something that has been bantered about for many years. I accepted it without testing the validity for myself for a long time. I have found that this was probably the excuse that was given for not knowing how to adjust development to the DR needed. My experience has shown the Callier effect lacks validity. If you haven't tried this for yourself, then I encourage you to determine the accuracy of these statements without simply accepting either Ansel Adams or Fred Pickers pronouncements.

Donald Miller said:

My experience has shown the Callier effect lacks validity. If you haven't tried this for yourself, then I encourage you to determine the accuracy of these statements without simply accepting either Ansel Adams or Fred Pickers pronouncements.

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Don,

the so-called Callier Effect is a reduced transmission thru silver based film, due to light stray. It depends mainly on the aperture of the light source. It is a matter of fact that a condenser enlarger produces a higher contrast than a color head with diffuse light. This *is" the Callier Effect. However, some photographers believe, that the Callier Effect also affects the shape of the density curve (i.e. that the effect changes over density and can, e.g., improve shadow detail). This isn’t necessarily the case in practice.

Apart from the aperture of the light source, the Callier Effect is dependent on:
- grain size and shape
- aperture of the enlarger lens
- film gamma and density

However, the impact of gamma and density is usually much smaller than that of the light source. The effect of grain, gamma and density are much depended on the film type. We have to take into account, that modern film has different characteristics than the one used by former masters. So we may come to different conclusions today.

Enter my name on the "Callier Effect Simply DOESN'T Exist" list.

Donald
"I encourage you ... without simply accepting Ansel/Fred pronouncements."
I also encourage you to learn a little of physics.

dear people...
this so called callier effect and this change in curve is another approach. as donald says - u can use it for creativity, or u can re-adjust your exposure/developing.
as a philosopher i will say - theories are great thing and great fun to deal with, but be practical (yes, based on your theoretic knowledge which primerly comes from "practice" and "logic")
in practice - both light sources have their own characteristic which can be used by the printer. it is like a differance between the fender stratocaster and the gibson lespoul guitars... which one is best???
come on - this question is not serious - i love both handricks and jimmy-page sound and gilmour sound and many others.
wether u r roll or sher film user - these heads will give different character. if u do prefer one of them - based upon your expiriance (and not theories whithout a real visual sense of the light sourse outcomes on the print) - if u prefer one of them, it ok too.
it is like to ask which leica lense is more normal 35 or 50. i dont know actually. the 35mm is more rewarding to the space perception and delivers more dynamic sense. the 50mm is more normal in terms of human eye magnification ratios of objects in different distances, and the perception of space is more concentrated, giving a more solid sense. u know how to use them and u use them based on your feelings, senses, intuitions and needs.

in creative photography (and anything which is concendered to be creative) - differances (in nature and essesne of things) are not a matter of advantages or disadvantages - differances are options, and options extened the creative abilities if u know how to use them and how to explore them.

there is some "field" where the print on the condenser and the print on the diffuse will be hardly difined, but there are huge fields where each one of them demostrates its own character. if one want to choose only one head, he/she should consider which direction is prefered.

personally, i love both of them. and if i have to gave up on one of them - it will be very difficult situation, but i would rather stay with the condenser. but this based not on "dry theories" but on my vissual sense and practical use - there is a unique character of condeser that i wouldnt gave up.