Converting a 6x9 enlarger to (approx) 4x5 enlarger

[tonyowen]

Has anyone every tried, or know of any attempts, to convert a 6x9 (cm) enlarger into an enlarger that would (almost) cover 4X5 (inch) negatives??

I can visualize problems - but some problems can be minimized whereas others are immutable.

The (specific) enlarger in question is a Krokus 69 which I've had since the 1980s - but I'm after more general responses.

regards
Tony

[Doremus Scudder]

General response:

I don't know the situation in the U.K., but here in the States, 4x5 enlargers are relatively plentiful and cheap; relative, that is, to the trouble and time it would take to custom modify a medium format enlarger. If you want to work in 4x5, I'd start looking for a used 4x5 enlarger in good condition.

Best,

Doremus

[Jim Jones]

I agree with Doremus. If this isn't practical where you are, converting the Krokus would be difficult. The entire light source and condensers won't work. Perhaps the easiest conversion is to fix a box on top of the negative stage that holds the 4x5 film flat about 1.5 inches higher than the 6x9 negatives. The old Elwood enlargers used a wood negative holder that slid into a slot. Such a negative holder can be built up from slats of wood. Some Elwoods sandwiched the negative between two sheets of glass, but this may be unnecessary. Above the negative holder is an opal glass diffuser somewhat larger than 4x5, and above that, the light source. The opal diffuser could be replaced by condenser lenses, but this may place quite a load on the 6x9 Krokus body. Even if you fabricate such a modification, some tinkering may be necessary to get uniform illumination across the negative.

[Bob Salomon]

I agree with Doremus. If this isn't practical where you are, converting the Krokus would be difficult. The entire light source and condensers won't work. Perhaps the easiest conversion is to fix a box on top of the negative stage that holds the 4x5 film flat about 1.5 inches higher than the 6x9 negatives. The old Elwood enlargers used a wood negative holder that slid into a slot. Such a negative holder can be built up from slats of wood. Some Elwoods sandwiched the negative between two sheets of glass, but this may be unnecessary. Above the negative holder is an opal glass diffuser somewhat larger than 4x5, and above that, the light source. The opal diffuser could be replaced by condenser lenses, but this may place quite a load on the 6x9 Krokus body. Even if you fabricate such a modification, some tinkering may be necessary to get uniform illumination across the negative.

On top of all that the bellows on the enlarger is probably too short to use a 120 to 150mm 45 lens and the 69 lens that the enlarger does use would not cover a 45 neg.

[Luis-F-S]

Why bother? Used 5x4 DeVeres have to be as plentiful used as used Omegas are here in the States. All you'll do is ruin a 6x9 enlarger.

[tonyowen]

All you'll do is ruin a 6x9 enlarger.

Thank you all - you've confirmed by assumption, but it does not harm to ask - after all if you don't you don't get.
One geographic/market point - the availability of "used" 4x5 enlargers at a "reasonable" price is very small in the UK compared with North America. In addition their costs versus average income here is much worse than yours across the pond..
Again thanks to all
regards
Tony

[pdh]

For someone with the right mechanical & craft skills (and you presumably have them otherwise you wouldn't be considering the conversion), an alternative could be to build a light source & negative carrier so you can use your 5x4 camera as an enlarger.
I've seen numerous threads at APUG on this, and I'd be surprised if there were not a few here too if you have a look.

[tonyowen]

[QUOTE=pdh;1264440you can use your 5x4 camera as an enlarger.[/QUOTE]
Brilliant, thank you - why didn't I think of that!!!!!!
I've got a Calumet monorail, so as you've said I have the majority of the system.
regards
Tony

[Steve Goldstein]

I recall seeing a web writeup where someone converted a Beseler 23C to 4x5. As I recall he found that Omega carriers could be made to fit. It was a very nice job, and made me regret having sold my 23C (to get a 45MX) - the 23C could be moved in and out of my darkroom with ease, while the 45MX had to be disassembled to get it through the door and then very awkwardly reassembled in place.

Sadly, my link has rotted. I'll see if I can find it via the WayBack Machine.

[Steve Goldstein]

Found it! The first part of the article discusses the physical conversion of the 23C, the second is about an LED head the poster developed for it. The Wayback Machine didn't snag the photos, but the text description of the conversion is pretty good.

https://web.archive.org/web/20120607...rumbs/23c.html