PDA

View Full Version : Polaroid MP4 8x10 enlarger?



argos33
13-Nov-2009, 23:06
The school I work for is potentially getting rid of a Polaroid MP4 copy stand with what appears to be an 8x10 enlarger conversion. I may offer to buy it, and am just wondering if anyone has had experience with one of these? Or can someone confirm that is what it is from these crummy cell phone pictures? The light source works when I plug it in and everything seems to be in good condition. The head can rotate 360 degrees for wall (or ceiling?) projections, and the focusing bellows have a very long draw.

For those with experience, would this work well for 8x10 B&W enlargements?

Thanks

Evan

Allen in Montreal
14-Nov-2009, 07:02
The head is an older Aristo cold light head, most likely with a W45 lamp designed for use on graded papers, it can be adapted to VC paper by adding 40 yellow gel filters between the tube and the frost glass diffusion plate. The scale of the VC papers will not be 100 percent, but it will certainly be printable.

Check IC-racer's great thread on rebuilding a Durst 1840, he explains this process very well.

I don't see any reason why you can not print on this unit. It may not be a Cadillac but I bet it works just fine! Take it if you can.

Richard M. Coda
14-Nov-2009, 08:41
Allen:

Do you mean one 40Y per grade?

Donald Miller
14-Nov-2009, 08:56
Allen:

Do you mean one 40Y per grade?

No, just add a global 40Y to offset the preponderance of blue light from the older Aristo lamps. This has been a matter of practice for some years.

Donald Miller

Richard M. Coda
14-Nov-2009, 09:22
No, just add a global 40Y to offset the preponderance of blue light from the older Aristo lamps. This has been a matter of practice for some years.

Donald Miller

But then how do you make it VC? You're only adding one filter.

Allen in Montreal
14-Nov-2009, 09:28
Richard,

You place the 40 yellow inside the light head, between the tubes and diffuser plate.
The head is then transmitting light that is more in sync with the VC papers and you use below the lens filters for each grade. The 40 yellow is a permanent installation.
it is not perfect but makes it workable. You lose some of the bottom end and the top end of the scale, and the grades are slightly compressed at the upper end.
One of the best explanations of the contrast curve is shown in a graph you can find towards the end of IC-Racer's Durst 184 thread.
I don't have much experience with this system, I used it a little on my old Beseler 45, I generally printed with graded papers but tried in at times, it works.


Found the page in the thread:
Post 103 by IC

http://www.largeformatphotography.info/forum/showthread.php?t=32852&page=11

argos33
14-Nov-2009, 13:38
Thanks Allen, I will investigate further. Good to know about the filter.

Allen in Montreal
14-Nov-2009, 13:45
Let us know if you get it and set it up, I bet it is nice and steady and will be great to use.
We can't see if there is a lens on it, but a 240 Rodagon would do the job well, which you can find on the evil from time to time pretty cheap.

ic-racer
16-Nov-2009, 11:28
I can't add anymore to what Allen has said, just to make sure you realize that without a Wide Angle 240 lens, you may not be able to make very big prints.

Othewise if it is a good price, go for it!

argos33
17-Nov-2009, 16:06
Thanks ic-racer, yes it will be for free/trade so I am going to give it a try. I can also turn it horizontal for wall projections, but I imagine it would be hard to get the surfaces perfectly parallel. Maybe I can put it on a track or something.

Also, where did you get the 30Y filter material for your cold light head? Many thanks

Evan