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BradS
31-Jul-2008, 10:08
So, I have this pile of 4x5 color transparencies...and, what the heck do I do with them? I'm getting real tired of holding 'em up to the kitchen (north facing) window to share 'em with friends and family.

I was thinking of rigging up a slide projector of sorts. I have a few..."under utilized" Omega D series enlargers in various states of decay laying around the garage and I thought maybe, I could rig something up with some of these bits.

Has anybody done this?

Is it feasible?

Seems like there are a few difficulties to work out...

1) how to keep the condensers from tumbling out when oriented in the horizontal?

2) seems like the negative carrier is kinda clamped in place by the weight of the lamp hose/ condensers...would need some sort of springs or something?

3) How to keep from melting the slides? Would a cold light head work better?

would it work at all?

darr
31-Jul-2008, 11:23
I have used an overhead projector before in the classroom to show lf transparencies. I think cooling and having a large fresnel lens that collimates the light is necessary for viewing for a length of time and thus the invention of these type of projectors. Check Office Depot for pricing new ones and/or eBay for used ones. Just my 2 cents. :)

Darr

Wimpler
31-Jul-2008, 12:17
I have used a condensor from an old durst 609 (not quite as big as the 4x5 image area, but close), they are mounted in a seperate case that is removable from the enlarger.

I have 3 lenses (rodenstock) from a linhof 4x5 slide projector, they work very well. 150mm f2.8 if you want it nice a bright, longer lenses for when you have a bigger audience and want to keep the noise down.

Worked pretty well. Mount the slide between glass panels. Cool it with a good fan.

Donald Miller
31-Jul-2008, 12:23
How large a projected image and at what projection distance do you envision?

The projection distance will enter into how large a lamp you will need because light fall off will be a factor.

Most enlargers use pretty large wattage lamps. I converted a Durst 138 to a 1200 watt lamp and fan cooled the lamp housing...without cooling this lamp will melt heat absorbing glass and crack conventional glass.

Ash
31-Jul-2008, 14:01
The OHP idea is a good one.

You could add vented bellows to reduce flaring.

Darren Kruger
31-Jul-2008, 15:03
In the San Francisco bay area, check out Weirdstuff Warehouse (http://www.weirdstuff.com/) in Sunnyvale. I've seen used overhead projectors there but haven't checked the prices. I've also seen microfilm (microfiche?) viewers there if you want to really check your resolution of your film.

-Darren

BradS
31-Jul-2008, 15:23
Oh, yeah...weird stuff. just down the street from work. A micro fiche reader or over head projecter would be perfect.

Jim Galli
31-Jul-2008, 17:11
Make a projector as you surmised but with a bajillion watt led light source (Geary Lyons can help) and project your images on you neighbors house. Should go over well in California.

BradS
1-Aug-2008, 07:14
neighbors would't care...as long as my trees didn't drop any leaves in their yard! :)

Donald Miller
1-Aug-2008, 08:06
neighbors would't care...as long as my trees didn't drop any leaves in their yard! :)


Look at it this way, you can always offer night time tanning in the slack times.