Got the De Vere, now need more contrast

[G Benaim]

Hi all,

Finally got the De Vere home in one piece, and have started trying it out. It sure feels well built, and the low focusing knobs are a great design feature. I've been using a condensor enlarger so far for my 6x6 and 35mm work, and some of the flatter negs which I print at G4 on it can't barely get enough contrast at full magenta filtration on the DV dichro head. I tested it w the ilford filters too, soo it seems to be a diffusion effect. Now, I know about the contrast difference between cond and diff sources, and have just re-read the relevant section in Ctein's book, but am still a bit surprised at how little contrast I'm getting at full strength. I still have to reprint my important 6x6 work to see how it looks, and before I remodel my very small darkroom to fit the DV and remove my Durst condenser, so I'm curious if this is something you just live with using a diffuser head, and from now on just aim for contrastier negs, or whether there's a way to squeeze more contrast out of thhe diffuser and therefore not have to keep the condenser around. Anyway, learning all the time, glad to get some experienced input,

GB

[Brian Ellis]

As you obviously know, diffusion enlargers produce a lower contrast print than condensers, all other things being equal, though in my experience not to the the extreme of yours. Unless you want to undertake a selenium toning project for your old negatives or try to use a different head I think you'll just have to live with them and your new enlarger. Selenium toning the old negatives would increase contrast but only by about a half-stop equivalent so it probably wouldn't be worth the effort and risk. But of course as you suggest, for new negatives you can retest to obtain appropriate EI and development times based on your new enlarger's characteristics.

[Colin Myers]

Hi,
Just wondering which mixing box you have installed in the light source. You will have a larger box for a larger format and vice versa. If you have say ,a 5" x 4" box and are trying to print 35mm, you could suffer from too much light spread or lack of contrast
Colin Myers

[robc]

dichroic filters won't last forever. If they have faded which is quite possible then you won't get the contrast you expect. Also check they move in and out as they are supposed to.

contact http://www.odyssey-sales.com/ for advice and/or replacement if necessary.
They are the original manufacturer.

[Jay DeFehr]

Many dichro heads will only deliver G4 with VC papers, so your negs that print on G4 with a condenser head might not have enough contrast to print with your dichro head. I suggest increasing film development for higher contrast negs. Film development should always be matched to the printing paper and light source, and since this is a new light source, you can expect some adjustments to your film development. Good luck. One advantage of increased development is increased film speed, so it's not all bad. Good luck.

Jay

[Nick_3536]

About the mixing box. Any chance your box is yellow? An aged box won't help any.

[Don Hutton]

Nick raises an excellent point - open up the box and check that the foam lining has not yellowed - if it has, that may well be the problem. There is an outfit in Ontario Canada called KHB Photografix (http://www.khbphotografix.com/) who sell foam kits for the mixing boxes. As far as I know, the De Vere filters should just about last a lifetime (I'm told that they just don't fade significantly).

[G Benaim]

Thhe head is a dichro head, the filters move in all the way, the color of the light is very white without filtration, and the dichro filters add very strong colors when used. Bypassing the question of faded filters, I used the ilford filters under the lens and still got relatively little contrast at g5. This is for a neg that prints well at g4 w the condenser, so it's right at the edge of diffuser performance for contrast I guess. Ctein claims that a condenser can get more contrast out of a flat neg in the 4-5 range as long as it's well exposed, so that may be what I'm seeing.

[Colin Robertson]

For what it's worth, this is what I went through. For years I printed 6x6 PanF in a condenser enlarger. When I jumped into 5x4 this was my first surprise. FP4 (lower contrast film anyway) in a diffusion enlarger (LPL 7450 Mk2) gave me mushy, flat results. I had to change developer, and pick times which produced contrastier negs. Happy now. Oh, also, 5x4 seems to have a different ability to handle brihgt highlights. Shots where, for example, a bright sky might block up on small format film can be pleasantly easy to print on LF.

[Don Hutton]

Still open the lightbox and check for yellowing - the effect on the light output may not be significant to your eyes, but could still be mucking things up enough. The fact that the Ilford filter below the lens gives the same result makes me more suspicious of the "yellowed" lightbox - you would in effect simply be dialling in some yellow every time. With a condensor light source, you'd be gaining between 1/2 and a 1 whole grade in contrast anyway which means that your negs requiring grade 4 with the condensor source may be marginal to print with a diffused source anyway, and 10-20Y that you don't know about may be just about enough to confound you!