Wollensak 15" f/5.6 Raptar Telephoto

[Randy]

I finally mounted my 15" Walle Tele Raptar into a Betax #4 that had 210mm Velostigmat cells mounted.

So, the shutter is f/4.5 - f/64. The Raptar was f/5.6 - f/32. Any ideas on how to determine where aperture marks should be made for this lens?

Lens is 15" (381mm) but since it is a tele, infinity focus is at about 9.5" (241mm).
When I measure across the wide open aperture looking through the rear element, it measures 36mm. If I am doing this correctly - 381 / 36 = f/10.5 -or- 241 / 36 = f/6.6 ...?

Any ideas from the experts?

Also, I am not familiar with the cable release socket on these shutters. It looks like it has threads on both the inside and outside. What do I need to look for?

[Jon Shiu]

It takes a regular cable release. I would recommend calibrating your f stops at the focal plane with a meter as compared to another one of your lenses, as outlined in Steve Simmons book.

Jon

[Dan Fromm]

Randy, open the shutter's diaphragm as wide as it will go. If you can see the blades, stop, this procedure won't work.

If the blades can't be seen, slowly stop down until they're just visible. Then open until they just disappear. The aperture index will be at f/5.6 for the 250/5.6 Tele. It will be between two of the engraved apertures for the 210/4.5 cells that were in the shutter. f/8 for the 250 will be the same relative distance above the next higher engraved aperture as f/5.6 is above the next lower. And so on. The photometric method Jon recommended is much more problematic.

[Shen45]

Measure the iris in the barrel and close the Alphax to that same "hole" size. Mark that position on the Alphax/Betax and call it whatever f-stop is on the position of the barrel. Just repeat for the remaining apertures. You don't need the glass in either as the spacing of the barrel and the Alphax/Betax is the same.

[Randy]

Jon, thanks. I have the book and found the instructions (BTW, thanks for the lens/shutter )

Dan, the blades are visible when I open the aperture to f/4.5. When I go beyond f/4.5, they just barely disappear at the point the indicator stops...just barely. So you are saying that beyond f/4.5, when the blades just disapeer, that is f/5.6 for the 15" Raptar, correct? At that point, the aperture pointer is about 5mm before the indicated f/4.5. So, if I move the indicator to 5mm before the indicated f/5.6, that would be f/8, for this lens? And 5mm before the indicated f/8 would be f/11, and so on? Just want to make sure I understand your instructions.

Steve, I should have asked this question before I nearly destroyed the old aperture getting the lens cells out. Now I can't get the blades to move for measurements

[Randy]

It takes a regular cable release.

Jon

Jon, I have tried to screw a standard tapered cable release into this thing and it will not mount. The opening is visibly larger than the cable release and the inside is not tapered like the cable release socket on my modern Copal shutters that I have in front of me for comparrison. The threads inside do not appear to be striped or damaged either, so it seems that this shutter takes a different type of cable release than I am familiar with.



Is there another "regular" cable release that I don't know about? As can be seen from the picture, it also has threads on the outside.

[Dan Fromm]

At that point, the aperture pointer is about 5mm before the indicated f/4.5. So, if I move the indicator to 5mm before the indicated f/5.6, that would be f/8, for this lens? And 5mm before the indicated f/8 would be f/11, and so on? Just want to make sure I understand your instructions

Sorry, I don't think that will work. I just took a look at a couple of Betax shutters on eBay. They all have non-linear aperture scales, i.e., the larger the number the shorter the distance between numbers. What I meant was, for example, that if f/5.6 fell midway between marked f/4.5 and f/5.6 (roughly a quarter stop below marked f/5.6), then f/8 would fall roughly 3/4 of the way between marked f/5.6 and marked f/8, and so on.

The snag in your situation is that you don't know how many stops below marked f/4.5 true f/5.6 is.

And, in fact, you don't know whether wide open is actually f/5.6. To check this, open the diaphragm as far as it will go, hold the lens at arm's length, front facing you, and hold a ruler across the front of the lens. Measure (guestimate, perhaps) the diameter of the entrance pupil. If the lens is actually at f/5.6, it should measure roughly 44.6 mm. Between 44 and 45 ...

Then do the same with the aperture indicator set to f/4.5 and f/5.6. Actual aperture will be 250/(diameter of entrance pupil). And then you'll know what the marked f stops really mean. Which is what you need to be able to use the lens.

Good luck, have fun,

Dan

About the straight cable release socket. My Speed Graphic's body release is straight. A regular tapered cable release will work with it. Try one carefully and don't force anything.

[Jon Shiu]

Despite how the threads look, a common cable release does screw in. I have about 8 different cable releases and they all screw in and work fine on the Betax shutter.

Jon

Jon, I have tried to screw a standard tapered cable release into this thing and it will not mount. The opening is visibly larger than the cable release and the inside is not tapered like the cable release socket on my modern Copal shutters that I have in front of me for comparrison. The threads inside do not appear to be striped or damaged either, so it seems that this shutter takes a different type of cable release than I am familiar with.



Is there another "regular" cable release that I don't know about? As can be seen from the picture, it also has threads on the outside.

[Randy]

Thanks Dan, will play with it and do some figuring.

Jon, I have tried to screw in 5 of my tapered cable release and they will not catch. The threads on the cable releases are only on the tapered part and are to small in diameter to contact with the inner threads of the shutter's socket.

Now, I found a recently acquired cable release that I have, and it will not work on my other lenses because the previous owner must have been careless and the entire tapered part looks like it has been broken off...but, the threads on this cable release extend beyond the taper, on up about 1/8" onto the non tapered part. That part will indeed screw into this Betax shutter. None of my other releases have threads beyond the tapered part.

I am thoroughly perplexed :l Anyway, I now have a cable release that will work on the shutter

[TheDeardorffGuy]

As has been stated a Alphax or betax 4 is a direct replacement for the iris mount. Sharpness? Mine has a sweet spot at f 11. I've seen and shot with others that were sharpest at f16. Reading here that it does 5x7 was something I never knew till I put it on my 5x7 Graflex SLR tonight. FAR OUT! Me now has the worlds heaviest SLR. I have one 5x7 bagmag. Its an AEROMAG. It says Fairchild but its made by Folmer and Schwing and the septums are 3/32 masonite and there are 16 of them in the mag. its one heavy sucker. Its now a tripod camera.

Me Lady just discovered this lens amongst some darkroom gear that was her late fathers. It's mounted on a Graflex lens board. I would like to play with it as a possible portrait lens for 5X7. I read someone had mounted theirs into an Alphax #4 shutter. Anyone have any experience with this lens? I would like to know if it will be worth the expense / trouble of locating a shutter, and if there are any other shutter options for it.