Mixing Chamber for Saunders 4x5 Enlarger

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I have been using my Saunders LPL 4500 enlarger for over a year now and love it. The VCCE head especially gives me a source of joy not to mention paper savings when changing contrast. I have recently started shooting some 645 roll film. My printing times can be 80 or 90 seconds (not counting burning) for 11x14 prints with my 80 mm lens at f5.6 or f8. I don't really want to be wide open. Saunders sells a 35mm mixing chamber and a 6x7 (I believe). I occassionally do 35 mm, but not very often. I assume the 35mm mixing chamber would give me a hot spot on the 645 negatives so I am ruling it out unless someone suggests otherwise. I assume that getting the 6x7 mixing chamber will significantly reduce my printing times for both 645 and 35mm negatives. Any thoughts on how much ? I don't really mind the long times as much as not having the ability to stop down another couple of stops.

-- Paul Mongillo (pmongillo@thurston.com), April 05, 2001


Paul i'm not sure that there is a 35mm diffuser box, but there is a 6x7 one. i got mine used with the enlarger but find that i don't use it as i tend not to go smaller than 6x7. i would imagine that it would greatly improve exposure times but i wouldn't like to guess much regards paul

-- paul owen (paulowen_2000@yahoo.com), April 05, 2001.

According to Saunders, the 6x7 mixing chamber will increase printing speed by "up to 1/2 stop".


-- Chris Ellinger (chris@ellingerphoto.com), April 05, 2001.

Paul, check out the following Saunders web site. www.saundersphoto.com/html/darkroom.htm They have a 6x7 mixing chamber, there specs say it reduces the print time by 1/2 stop. I have the XLG with a 4x5 mixing chamber and a 35mm mixing chamber. You are probably correct about having a hot spot using the 35 chamber on 645, the chamber has a lens that focuses the light for the smaller format. I use the 35 chamber and it decreased my print time too much, I always reduce the light intensity using the light reducer on the XLG; not sure if this is available on your model. The XLG uses a 250W lamp, this also impacts print time. Not sure if the light intensity decreases with use, this may impact your print time. Maybe try changing your lamp and see. Hope some of this information helps.


-- Henry Macler (macler_henry@lilly.com), April 05, 2001.

I used to own a Beseler/Minolta color head that I used with 35 mm film. Then I moved to 6x7. The company literature advertised, for something like $250, a 6x7 mixing that they said wold cut exposure times in half. It seemed like a lot of money, but then cutting exposure times in half sounded good too. Only after I bought it did it occur to me that I could have cut exposure times in half by opening up one stop and saved the $250. My times weren't running as long as yours, and I don't know what the cost of the Saunders chamber is, but I'd think twice before spending a lot of money on something that was only going to reduce times by half a stop. Most enlarger lenses are at their optimium when used in the vicinity of one stop from wide open anyhow. Ctein, in his "Post Exposure" book, gives the results of his testing of the Componon S line of enlarger lenses. I don't think that with any of the ones he tested the optimum aperture is significantly beyond a stop from wide open and some are even less. The only time I expose with an aperture smaller than one stop from wide open is when a print requires a lot of elaborate dodging.

-- Brian Ellis (bellis60@earthlink.net), April 05, 2001.

Paul, I'm really shocked by your printing times. I have the same enlarger and while I usually print from 4X5 negatives I haven't noticed excessively long printing times with medium format negatives. I do however use the dichroic color module rather than the VCCE module and that may be part or all of the difference since the VCCE module adds ND filtration to force all printing times to be equivalent to full magenta filtration (grade 5). Still, I use a combination of both magenta and yellow filtration when I print to simulate a VCCE head. I assume the light attenuator is turned off (may not even be found on the VCCE module). I second the suggestion of checking the bulb before spending money on a smaller mixing chamber.

-- mitch rosen (mitchrosen@sprintmail.com), April 05, 2001.

"Up to half-a-stop" improvement in exposure doesn't sound worth the cost to me. That's only a reduction from 90 seconds to 64 in terms of printing time.
You might be better off changing paper brands, which vary considerably in their speed. Kentmere papers are among the fastest and best I've tried.

-- Pete Andrews (p.l.andrews@bham.ac.uk), April 06, 2001.


Yes,the VCCE head is very different from your dichronic. You have accurately identified why my times are longer than yours. And no, there is no attenuator on the VCCE head. By having the convenience of constant exposure regardless of contrast setting you are giving up some light intensity. Again, this has not been a problem with my 4x5 stuff, but I do want to shoot a bit more 645. I have e-mailed Saunders to see if they have any suggestions or if they feel that the 35mm mixing chamber would work for 645.

-- Paul Mongillo (pmongillo@thurston.com), April 06, 2001.

As a matter of interest, can the 4500/7451 which comes with a 200w lamp, be used with a 250w as in the 7452/xlg

-- paul owen (paulowen_2000@yahoo.com), April 06, 2001.

The different mixing chambers that go with a LPL 4x5 only help in reducing exposure time. Do they in any effect the quality of light falling thru the negative.

-- Dileep Prakash (dileep_june@hotmail.com), October 02, 2001.

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