Developing for Diffusion Enlarger?

[Chadinko]

I have been reading a lot, which seems to be a dangerous thing.

I have a Beseler 45MX enlarger with an Aristo D2 HI cold light diffusion head on it -- I have a couple of other condenser enlargers too but this is the only one I'm currently using.

A number of sites I've read mention developing film differently specifically for printing with a diffusion head, specifically one site mentioned adding 20-30% development time. I find this a little odd.

Is this something that is standard practice? Or is this someone's personal preference?

May have to run some tests, but before I waste the film and chemistry I thought I'd see what all the experts here have to say about this.

 

[Chadinko]

Thank you. I was a little puzzled when I ran across the assertion that adjusted development was necessary for different enlargers. I don't use a formula when I print; I print based on each individual negative and how I happen to feel that day and so each one is different. So I didn't see why it would matter what enlarger I was using.

 

[Ian Grant]

In recent years (last 40)many condenser enlargers use quite diffuse light sources and the difference is far less than the older enlarger with large lamp housings where you often needed to adjust lamp position with varying enlargement to get optimum results.

With the Durst's I've used I found no appreciable difference between a condenser or diffuser light source, my 601's use either and I have both (the diffuser is the CLS66 colour part).

Ian

 

[RobC]

+1

And

it's caused by the so called "Callier effect" see:

https://en.wikipedia.org/wiki/Callier_effect

enalargers where the light source is in the same axis as lens axis tend to exhibit it more than my dursts where the light source is directed via a reflex mirror. And the smaller the light source the more it happens too.

 

[ic-racer]

"I have a Beseler 45MX enlarger with an Aristo D2 HI cold light diffusion head on it -- I have a couple of other condenser enlargers too but this is the only one I'm currently using. "

Yes, compared to condenser printing you could develop for longer. However, if you only print with the diffusion head why would you change?

 

[Chadinko]

Yes, compared to condenser printing you could develop for longer. However, if you only print with the diffusion head why would you change?

Exactly. Though I do occasionally use a condenser enlarger (at a college darkroom, for example), but I just adjust my printing. I was just curious as to whether I needed to adjust my developing standard time to increase the contrast. My answer is no. Thanks guys.

 

[MattKing]

That approach was a lot more prevalent before variable contrast paper became the norm.

 

[RalphLambrecht]

I have been reading a lot, which seems to be a dangerous thing.

I have a Beseler 45MX enlarger with an Aristo D2 HI cold light diffusion head on it -- I have a couple of other condenser enlargers too but this is the only one I'm currently using.

A number of sites I've read mention developing film differently specifically for printing with a diffusion head, specifically one site mentioned adding 20-30% development time. I find this a little odd.

Is this something that is standard practice? Or is this someone's personal preference?

May have to run some tests, but before I waste the film and chemistry I thought I'd see what all the experts here have to say about this.

Yes, a softer light source needs a harder print to get the same tonal scale;adding 15%to the development time to adjust for printing on a diffusion enlarger seems reasonable to me.

 

[Doremus Scudder]

Exactly. Though I do occasionally use a condenser enlarger (at a college darkroom, for example), but I just adjust my printing. I was just curious as to whether I needed to adjust my developing standard time to increase the contrast. My answer is no. Thanks guys.

I'll haul out the condenser head from time-to-time in order to eek a bit more contrast out of a negative. Otherwise, it's diffuser all the way.

In the days of graded papers, photographers needed to be a bit more precise with their exposure and development in order to get consistent results. It's still not a bad idea to refine development time to produce negatives that print well on an intermediate paper grade. That way, the inevitable misses will fall within the extremes of the contrast range. For sheet film users, I still think it's better to expand and contract development for known low and high contrast situations respectively than to simply rely on VC papers to do the job.

Doremus

 

[Chadinko]

It's funny though that the light here in Arizona is so harsh that I tend to print with a lower contrast filter (#2 or 1 1/2) anyway. More contrast is nice on occasion but lately I've been going lower.

 

[Luis-F-S]

Develop for a Zone VII density of 1.15 over the film base.

 

[Chadinko]

Boy you guys are throwing numbers that I don't even understand... I know the Zone system, but would you mind kindly explaining what developing for x over the film base means? I've always just developed according to the time chart and been satisfied with the results but if I can be MORE satisfied (like Orwell's "more equal," I guess?) then I'd be a happy camper.

 

[rpavich]

Interestingly enough, I was pursuing the Kodak information sheet for development times for T-Max and found that their publish times are for diffusion heads, and they recommended shortening it for condenser heads. I had never known that.
So...it would stand to reason that the published times are correct for you.
This is what they said:

These starting-point recommendations are intended to produce negatives with a contrast appropriate for printing with a diffusion enlarger. To print negatives with a condenser enlarger, you may need to adjust the contrast by reducing your development time; see “Adjusting Film Contrast.”

Here is the link
http://www.kodak.com/global/en/professional/support/techPubs/f4043/f4043.pdf

I'm a noob....so take my conclusion with a grain of salt.

 

[Chadinko]

If I may be presumptuous here… I’ll assume that you have a densitometer, otherwise all those numbers will have little value to you. You say you know the Zone System, so I’m a bit surprised that you’re not familiar with the term “film base plus fog” (I abbreviate it as fb+f). When a film is developed in your chosen developer, measuring the resulting density in the clear area of unexposed film will yield a density value that is the sum of the clear film base and a bit of development fog (which can vary slightly for different development times). As the film receives more exposure, additional density accrues in the emulsion. The Zone System normally defines the personal Exposure Index (EI rather than ISO) as the amount of exposure that produces a density reading of .10 above fb+f and is labeled Zone I. One more stop of exposure builds up more density that is labeled Zone II, and so on. This is all explained in greater detail in AA’s The Negative, where you’d find that development for Normal contrast with a diffusion enlarger would target a density reading of 1.30 +/-.05 above fb+f, which is labeled Zone VIII. AA refers to the amount of density above fb+f as NET density. Since I use only sheet film, I tape a Stouffer 31-step wedge to the film in the holder and expose the film to a specific amount of light reflected off a white mount board with blue floods (to come close to daylight). So with one camera exposure I get a series of 1/3-stop exposures on film, that enable me to plot the characteristic curve to Zone VIII and beyond. Repeating this procedure for various development times yields a family of curves from which I can estimate the times needed for N+ and N- contrasts.

I am familiar with the Zone system. I didn't say I adhere religiously to it I do not have a densitometer; in fact I'm not sure I've ever even seen one before. I've heard of it, of course, but it's never been important enough to me to go find one and use it. At this point, I'm not sure it's that important to me even now, especially at the prices I'm seeing for one on the Internet!

Does the Stouffer behave in a manner similar to the circular-pie Kodak exposure wheel? I've been using one of those and it's cut my time and expenses dramatically when making test sheets and initial prints. I've been shooting mostly sheet film and 120 in a 6x6 SLR and I've been using a Sekonic L-518 meter, and it seems to be working ok for me. And I'm going to print out your comment and read it through more thoroughly when I am not at work and have the brainpower to fully digest it.

Interestingly enough, I was pursuing the Kodak information sheet for development times for T-Max and found that their publish times are for diffusion heads, and they recommended shortening it for condenser heads. I had never known that.
So...it would stand to reason that the published times are correct for you.
This is what they said:

Here is the link
http://www.kodak.com/global/en/professional/support/techPubs/f4043/f4043.pdf

I'm a noob....so take my conclusion with a grain of salt.

Except I'm not shooting Kodak film... It's too expensive for me. It's interesting, though, and I'll have to go look at the information sheets for the films I'm using and see what type of enlarger the manufacturers are recommending. I'm more of a stick-and-rudder sort of printer, I guess, but I do need to be thinking through the print from the camera exposure on. Onward and upward, huh.