Alphax Shutters on e-bay

[Drew Bedo]

Hello Everyone,

For months past I have noticed a bunch of oscilloscope camerasoffered on e-bay offered for hundreds of dollars each. Not surprisingly, they don’t sell. No one wants to buy these useless 50s-60s era industrial cameras. Now they are being offered at buy-it-now prices of <$50 and <$25 .Most of these cameras have a 75mm/f1.9 Wollensak lens in an Alphax #3 shutter. They won’t cover 4x5 at infinity (make a 6cm circle on 4x5 film), but they are optomised for 1:1 reproduction at short working distances where they do cover 4x5 . . .and max aperature is f-1.9. I’ve gotten two at $25 each, and c lose-ups seem fine to me. Had to work some to dismount/disassemble them from the camera though.

If we don’t buy up all these old shutters at thrift store prices, they will eventually get junked —and they will be lost to LF photography forever.

[Dan Fromm]

Drew, take a look at the back of the shutter. The shutters I've seen with 75/1.9 'scope lenses in them -- Alphaxes and Ilex #3s -- have all had restricted apertures. They're not as useful as they seem.

Oh, and by the way, I just took a look at 'scope cameras on eBay. Most of the ones on offer have completely useless electronically-timed shutters. The only ones that are remotely safe to buy are Tektronix C-12, C-19, C-27, and C-58P (Ilex shutters mainly, some with Alphax), Hewlett Packard 196A and 196B (Alphax), and Polaroid DS-31, -34, –39, Shackman 7000 and Tektronix C-4 (Copal Press, mainly #0).

[jp]

I was curious how these lenses might be in medium format use. I'd think it would be fun to have something brighter in 6x6cm.

[Drew Bedo]

Don: OK, I see now that the clear aperature wide open is about 20mm not the calculated 39mm (75mm devided by 1.9 = 39mm). So then, does that mean that the aperture scale is off across the range?

[Dan Fromm]

I was curious how these lenses might be in medium format use. I'd think it would be fun to have something brighter in 6x6cm.

I wouldn't bother. At the moment I have cells from a 75/1.9 Oscillo-Paragon (nice magnifiers) and a 75/1.9 Oscillo-Raptar in a dead Alpax. Dead Alphaxes seem to be a risk. The Ilex Universal #3 the Oscillo-Paragon was a very pleasant surprise; all of its speeds are good, including 1/100.

[Dan Fromm]

Don: OK, I see now that the clear aperature wide open is about 20mm not the calculated 39mm (75mm devided by 1.9 = 39mm). So then, does that mean that the aperture scale is off across the range?

Drew, the aperture scale is correct for the lens sold in the shutter. For other lenses, you're on your own.

[Drew Bedo]

Don: I nderstand that the indicated aperature is a ratio of the focal length of the lens and the physical opening of the shutter and will change with the glass. My question related to the expected physical measurement of the max aperature being less than the value calculated from the focal ratio.

You pointed out that the shutter was restricted, and I went back and measured mine. It doesn't measure as I expected and I don't know why. Anyone?


At one time during the last decade of the previous century, I bought ten of these cameras for ~$5 each. I disassembled them and discarded everything but the lenses. Some were Paragons and some were Raptsrs. The shutters were both Alphax and Betax #3s. All these shutters worked pretty well and the glass was prestine. As an ocilloscope camera, they were not used heavily.

I sold them at the old Houston Camera Show over several years. Now I have two of them again, and mine seem to work well within their design limitations.

I'm just pointing out that there are a bunch of #3 self-cocking shutters available now at DIY project prices. Sure there are better shutters available. Sure there are better lenses available. None for under a Ben Franklin.

[Dan Fromm]

Ah. Common misconception. The f/ number is not focal length divided by the aperture's diameter. It is focal length divided by the entrance pupil's diameter. The entrance pupil -- the image of the aperture formed by the lens' front cell -- need not be the same size as the aperture.

[Drew Bedo]

Don: Thanks for that clarification. Measured THAT way it works out as axpected.


Don: With the above cleared up, what is the issue about restriction on these shutters and how does it limits the use of these shutter for repurposing in the context of DIY photo projects?

You are correct about the electronic shutters, I've tyaken apart many of these cameras in the 1990s and not all are salvagable. As in all things DIY, you gotta look carefully. The big thing here is that the asking price is comming down so dramatically that if none of them are salvaged they will probably be junked and lost to photography for ever.

[Dan Fromm]

Druw, my name is Dan, not Don.

A shutter whose maximum opening is smaller than standard is not as useful as one that's to specification. There are two problems.

When front-mounting a lens, if the maximum aperture is smaller than specification vignetting will be worse than necessary. I had this problem with the Ilex #3, ex-'scope camera, I stuffed my 60/14 Perigraphe into. Fortunately the maximum opening can be recovered by removing the entire diaphragm mechanism but this ruins the shutter for other uses. This is why Polaroid MP-4 shutters are so cheap. They're #1 press shutters with no diaphragm, so useless for all applications but front-mounting.

When a lens is mounted in a shutter with restricted maximum opening, using it at full aperture may be impossible. This is a problem with, e.g., putting G-Clarons in ex-Polaroid Copal Press and Prontor Press shutters. Some years ago when Mr. Galli had a bunch of G-Clarons he'd put in Polaroid Copal shutters to sell he waltzed very very carefully around this.

'scope camera with electronic shutters are useless junk. No one will lose anything if they go to the landfill or the materials they're made of are somehow recycled. They're easily recognized, I explained how in this http://www.largeformatphotography.info/forum/showthread.php?88943-Oscilloscope-cameras-as-a-source-of-shutters post.

I wouldn't advise anyone who wants to replace an existing kaput shutter to buy a 'scope camera with a 75/1.9 in Alphax or Ilex to buy the camera at any price. 75/1.3, yes. 125 mm, yes. 75/1.9, no. 75/1.9 for play, yeah, sure, why not?

[Drew Bedo]

Hello Dan,

Sorry, I'm visually impaired and didn't catch the little tail on what i thought was an o. I know how anoying it can be when someone gets your name wrong. Its surprising how many different pronuunciations can be made out of my last name!

Thanks for explaining the ins and many outs of o-scope lenses and shutters. Your expanded explanation in a separate post on this forum goes a long way in providing information that I was completely unaware of.

I thank you.

[Dan Fromm]

Thank you, and you're welcome too.

[Dan Fromm]

Graybeard, you and I agree nearly completely about the usefulness of Alphax and Ilex shutters recovered from 'scope cameras. Where we disagree on that is about the usefulness of ones with limited maximum openings. See my comments earlier in this thread.

We also agree -- and I'm delighted by this -- on the usefulness of these shutters for front-mounting lenses.

Where we part company completely is on the wisdom of buying any old oyster, sorry, 'scope camera, in the hope of finding a pearl, sorry, usable shutter. Buying any old 'scope camera will get mainly cameras with unusable, often small, electronic shutters. Been there, done that, don't recommend it.

[Old-N-Feeble]

Yeah... I've seen a few sellers buy barrel-mounted lenses and just screw the cells into dime-a-dozen Polaroid shutters with limited success. Some work perfectly in all adaptations... some work in limited adaptations... others are of little use. Check histories here, on APUG, and other photo sites.