5x7 cold light source enlargers

[Peter Korpan]

What is the real benefit of using a cold light source in an enlarger for black and white work - can you tell the difference between this type and one with a condenser? I am looking for a 5x7 enlarger with a cold light source, but now I'm not sure I should limit myself to that type of light source.

[Bill_1856]

Negatives don't "pop", and you don't need a 10' ceiling in the darkroom.

[jnantz]

dust and scratches aren' t as evident with a diffused light ( cold light) source.

[Ken Lee]

With a diffused light source, you don't experience the "Callier Effect". According to that principle, highlights (dense areas in the negative) block the passage of light more than other shades. The result is chalky, blocked detail in the high values.

I tested this for myself over 30 years ago, and even tried spray-painting the inside of my condenser enlarger head with white paint. There was no visible difference. Eventually, I bought a cold light head. It made all the difference. You can see the before and after images in a book from that era, called "Zone VI Workshop" by Fred Picker.

[Brian Ellis]

I think it's been pretty well documented that Fred Picker and Ansel Adams were all wet (yes, even Ansel wasn't perfect) when they said condenser light sources produced "soot and chalk" prints and that diffusion light sources were inherently better. As long as you develop your negatives with the use of a condenser enlarger in mind, which generally means negatives of lower contrast than you would produce for a diffusion enlarger, I believe it's now generally accepted that you can make the same print from either type. Among other sources, there was a lengthy article in Photo Techniques magazine a few years back demonstrating this fact.

The reduced effect of dust and scratches and lack of negative "popping" with diffusion light sources that someone else mentioned are commonly cited as benefits so I assume that's accurate, I've never used a condenser so I have nothing with which to compare my diffusion light source to in that respect.

Zone VI enlargers sold by Calumet are 5x7 enlargers for which a diffusion head is made.

[Ken Lee]

Brian - Thanks for the update. Geez, I come back after 30 years, and I don't recognize a thing. Next thing you know, they'll be putting a man on the Moon !

[ernie]

This is remarkable.

I was just re-browsing Fred Picker's 1974 book titled ZONE VI WORKSHOP and read with amusement the apparent frustrations of one of Fred's students, who went to all kinds of trouble in modifying his condenser enlarger in order to produce prints that fit the contrast range of his negatives. He tried diffusion glass in the filter drawer. Then he tried diffusion paper. To no avail.

Then... to quote Picker... "...he gave up the fight and at my suggestion he bought an inexpensive (under $100.00) cold light head for his Beseler enlarger. It solved all of his problems and he is making very fine prints. The student's name is Ken Lee of 209 Mamaroneck Road, Scarsdale, N.Y. He has kindly agreed to verify all of the above."

Small world.

[Peter Collins]

WOW--it IS a small world!!

[Ken Lee]

For the record, I no longer live at that address. People sent me negatives to test for quite a while. I wonder if the current resident continues to get them.

[wfwhitaker]

Originally one of cold light's greatest benefits (now often overlooked) was as an economical light source for large negatives. Condensers for 5x7 and larger negatives were very costly to produce. They still are, but with so many labs leaving the analog realm, there are often very good buys on used 5x7 and 8x10 enlargers with condenser heads. Having said that, my own enlarger is an old Durst 5x7 to which I've adapted a Zone VI VC cold light head. The original motivation was because I found the head used at a good price. But since installing it, I really do "interact" well with it and enjoy the ability to change contrast very easily. The diffused light source also works very well with the "selective masking" technique which Alan Ross documented in several articles a while back in View Camera magazine.

As you say you're looking for a 5x7 enlarger, I would personally recommend a Durst 138. They're wonderfully made machines and if you're patient, one will come along at a good price. Normally they do come with condenser heads, although dichroic heads are available. The conversion to cold light is very simple. (Aristo even makes a single lamp cold light source for the Durst which simply replaces the lower condenser.) Should you be interested, I'd be happy to describe what I did to convert mine to accept the VC head. The Zone VI enlarger from Calumet comes with one cold light head or another. Other vintage enlargers (Elwood, Omega, etc...) which are capable of 5x7 occasionally show up on the market. Most any enlarger can be converted to cold light if that's what you want. My advice (FWIW!) would be to evaluate the market based upon how much you want to spend and what's available in your timeframe. I wouldn't worry too much about the light source initially.



I happen to like using cold light myself. But it remains true that wonderful photographs have been made and will continue to be made with condenser enlargers, too.



Good luck!

[Tom Potter]

I am going to replace the old light source in my Durst 138S with a 5X7 cold light, Aristo D54. B&H quotes them at about $650.00.
Is there a reliable source for a "pre-owned" one that you know of? I am not rushed on this since I am working with other materials as well, but want to start the process of finding one soon. I may just decide to buy a new one.
Tom Potter

[Jim Michael]

I recall printing a badly scratched neg (looked like it had been cleaned with steel wool) for a customer several years ago with my Omega D2. I made test prints with both the condenser and with the Aristo cold light. The degree to which the scratches were suppressed with the cold light was just amazing. I probably used Edwal No-Scratch for both tests as that was the usual practice then.

[Nathan Potter]

One should point out what Jim Michael above has alluded to above. Defects including slight scratches and dust in a negative can be very effectively reduced using a diffusion head in the enlarger. This is one of the advantages in using such a head. OTOH that same effect can reduce the fine detail in certain negatives. Whether one chooses diffusion or condenser depends on the effect you are looking for. In either case you should develop a negative for a contrast index that fits your enlarger and the vision you are looking for in the final print.

Nate Potter, Austin TX.

[ic-racer]

Negatives don't "pop", and you don't need a 10' ceiling in the darkroom.

Agree, that sums it up.

[Drew Wiley]

Always use an oversize cold light, larger than the negative you plan to print. This is
because the perimeter the cathode tube doesn't produce even illumination. And be aware that some of the older cold lights can behave flaky. New ones aren't terribly expensive for this size work. I'd check with Aristo, and would specifically recommend the blue-green light for VC paper.

[Ken Lee]

On further reflection, another advantage of diffused light, is that it basically mimics the results of contact printing. You might see that with diffusion light, "what you see is what you get".

I would be interested to read the article which illustrates that both types of light can be used with equal success. Doesn't the Callier effect remove separation, mainly in the dense portions of the negative ? Wouldn't this disproportional effect, amount to the opposite of what we see with compensating developers, which increase separation in the low values ?

[Peter K]

Wouldn't this disproportional effect, amount to the opposite of what we see with compensating developers, which increase separation in the low values ?
No, if one needs the last information from the negative, from the low and high values, one needs a double condenser and a point lamp. Condenser, lamp and lens has to be aligned very carefully. And if the lens can show best resolution wide open, the lens cannot stopped down with point light, one can see all information from the neg on the print. But as mentioned before all scratches and dust particles too.

Point source enlargers are use for microphotographic negatives and in the field of the graphic arts. But with other negs one has a lot of work with spotting.

Peter K

[Nathan Potter]

Yes Peter that is my experience. I use a point source condenser head occasionally in my home darkroom. It is a home design with a virtual aperture in front of the halogen bulb so that the degree of contrast can be altered to suit the style of print desired. The idea of course is that all rays from a point light source reach the paper from a single angle (more or less depending on how pointy the source is). Grain is dramatically emphasized as well as any kind of defects. Maximum contrast is achievable to the point of being distasteful due to the almost complete lack of off axis modulation of of tonal values. Contact printing is vaguely analogous in that replication of detail is pretty precise due to the proximity of the neg to the paper but there is a degree of tonal modulation because the normal bulb or cold light head is an extended source.

Another way of looking at it is to consider a point source a large f/no. (meaning small aperture) while an extended source is a small f/no.

Nate Potter, Austin TX.

[Ken Lee]

"I was just re-browsing Fred Picker's 1974 book titled ZONE VI WORKSHOP and read with amusement the apparent frustrations of one of Fred's students, who went to all kinds of trouble in modifying his condenser enlarger in order to produce prints that fit the contrast range of his negatives. He tried diffusion glass in the filter drawer. Then he tried diffusion paper. To no avail."

Also for the record, I was not trying to match the *contrast range* of the negatives - but something a bit more subtle: trying to produce prints which matched my contact prints, which showed un-blocked details in the higher values of the waterfall.

I am delighted to be proven wrong about the Callier Effect, decades later as it were. If someone can explain this nicely, and show some sample images, I will be most grateful.

The images I made back then, with condenser light, displayed an abrupt "shoulder" you might say, while those made with the cold light head, matched the contact prints, under otherwise identical conditions, and continue to do so today.

[Clueless Winddancing]

Re OLder Durst 5/7 Cold light heads: The unit can come in two packets that can slip into the condensor head. Each can be the replacement for the two condensors. Or, one can also put the lamp packet above and condensor in the lower portion of the head. Whether this might produce an intermediate level of diffusion I do not know; or, if it might just broaden the "feather" of the illumination -I do not know. Additionally, there were 3 different types of gas (tubes) made by Aristo Lamps: B/W, VC (B/W), and color back in the olden days of 1950s, 1960.

[ic-racer]

Yes Peter that is my experience. I use a point source condenser head occasionally in my home darkroom. It is a home design with a virtual aperture in front of the halogen bulb so that the degree of contrast can be altered to suit the style of print desired.

OFF TOPIC: there is a poster on APUG that is trying to do a point source conversion. Perhaps you could lend some expertise? http://www.apug.org/forums/forum43/56881-bulb-recommendation-needed-point-source-enlarger.html

[Nathan Potter]

Yes, I posted a bit more information on that thread.

Nate Potter, Austin TX.