De Vere 5108 5x5 Light Box

[Luis-F-S]

Can anyone tell me how much of a difference the 5x5 light box makes over the 8x10 one? They're pretty pricey and I only have the 8x10. I'm trying to figure out if it makes sense to get the 5x5 for medium format negatives or if the difference will be marginal for smaller sized prints (8x10 to 11x14). Thanks! L

[ic-racer]

Can anyone tell me how much of a difference the 5x5 light box makes over the 8x10 one? They're pretty pricey and I only have the 8x10. I'm trying to figure out if it makes sense to get the 5x5 for medium format negatives or if the difference will be marginal for smaller sized prints (8x10 to 11x14). Thanks! L

I have some Durst literature on the relative intensity of the various lightboxes. Durst claim a two-stop increase going from the 10x10" box to the 4x5" box. Or a one-and-two-third increase going from the 8x10" box to the 4x5" box.

[Luis-F-S]

Thanks IC, I was really more interested in people's experiences in printing MF with the 8x10 light box and if it resulted in "reasonable" exposure times in B&W with moderate enlargements, ie 8x10 & 11x14. L

[IanG]

Luis, my De Vere 5108 only came with one mixing box the 10x8 one, that's all the lab it came from ever used. I find it fine for MF negatives, there's 1000W of light in the head and there's not a problem in terms of exposure times, they are shorter than with my MF enlargers (Dursts) for the same aperture.

Ian

[Peter De Smidt]

You get 1 to 2 stops more light.

[Luis-F-S]

Thanks Ian and Peter

[ic-racer]

Can't you just print some negatives and see? Only you would know if it is worthwhile. If your medium format printing times are 150 seconds or 15 seconds with the 8x10 box only you can find out.

[Luis-F-S]

Pretty much what I did tonight IC, print times for 6x6 negs to 8x10 with a 135 Rodagon were around 24-30 secs, which is perfect for me. Some where a bit shorter, so I dialed in some density. Worked like a charm. I've also got my head at lamped 1000 Watts with 250 W ENH bulbs instead of 300 W ELH bulbs, so I always have the option to lamp up to 1200 if needed, or use a shorter lens. The lower wattage ENH bulbs are rated at an average lamp life of 175 hours vs. 35 hrs for the ELH.

[ic-racer]

Those smaller mixing boxes are probably most useful when doing very large prints. For small prints you are probably better off with less light. In fact, the Durst head even has a semi-calibrated, non-diffracting aperture between the lamp and the mixing box to cut light intensity for small prints.

[Luis-F-S]

Yup, pretty much what I found. I assume the aperture in the Durst is in the shutter of the CLS 2000 colorhead, as my CLS 301 did not have one that I'm aware of. Had to dial in density if necessary there also. Some heads have an ND filter you can dial in which is nice, LPL has a "diffusor screen" on their dichroic heads that give around 2 stops density, but nothing in their VCCE head. L

[Luis-F-S]

This is an update, I sort of decided that it was not worthwhile spending the money on this, but Kevin Brown of KHB Photografix wrote me a very detailed explanation of the single vs multiple lamp systems for different mixing boxes. I thought I'd share for general knowledge to the list:

Single lamp systems like most 4x5 enlargers work well when you concentrate the light down to smaller formats. Most will give you a 1-1½ stops increase in light output from 4x5 to 6x7 and 2-2½ stops from 4x5 to 35mm. However the multilamp systems like the 5108 are not nearly so efficient. The 4 lamp system of your 5108 was designed not for maximum light output but for maximum evenness of the light (both intensity and colour) from corner to corner. Efforts to concentrate the light from 4 widely spaced lamps down to 5x5 or smaller do not work so well. I have checked for actual specs and I don't believe DeVere ever published any. But, my recollection is that going from 8x10 to 5x5 the light output is increased by only 1 f-stop and going to 6x7cm gives only a marginal further increase of about ½ stop.

In general the concept of using 1200W to evenly illuminate a 10x10 negative area does not translate very well when trying to print from 120 or 35mm negatives where you are using (in the case of 35mm) les than 2% of that light.

There are vast differences in the light output of different enlargers. The Wattage alone means very little. I had one customer making wall murals from 2 Durst 184 enlargers. One outfitted with a 2000W Durst lamphouse and the other with a 1000W Chromega F lamphouse. The 2000W watt exposure was in the neighbourhood of 20 minutes and the 1000w Omega less than 4 minutes. But, they loved the Durst because the light was so so even. Eventually they manipulated the negative to compensate for the unevenness of the Omega and banged out prints in about 6 minutes.

[Luis-F-S]

A further update to an ancient thread, so after finally getting the 5x5 mixing box from a forum member, I thought I'd try to print some MF and 135 negatives to see what a difference it made. As Kevin Brown noted above, very little light increase; less than 1 stop. Also in Emails with the DeVere folks in the UK about the 240 mixing box, they said that they made very few of the 240 mixing boxes because there just wasn't a demand for it, and no longer make them.

[ic-racer]

Thanks for the update.