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esearing
20-Jan-2017, 12:41
Is there such a thing as a wide to medium convertible lens for 4x5? IE 70mm f5.6 to 135mm f8. I have 150 and 180 convertibles but have not seen wider.

Or would it be feasible to have screw on front elements that widen or tele a normal lens?

Luis-F-S
20-Jan-2017, 13:29
No you buy a wide angle lens.

Dan Fromm
20-Jan-2017, 13:36
It seems that early f/6.8 dagor type Symmars were convertible. They were as short as 60 mm. And early later f/5.6 plasmat type Symmars were convertible. They were as short as 80 mm. Nothing that will cover 4x5, though.

People ask here about afocal converters from time to time. No one seems to use them much. I think that's an answer to y'r question.

esearing
20-Jan-2017, 13:59
No you buy a wide angle lens.

Sometimes you don't want to carry 4 lenses when 2 would suffice. I do a good bit of hiking with 4x5 and would like to reduce weight so looking at lenses , lighter film holders, etc...

Bob Salomon
20-Jan-2017, 14:12
Most convertibles are terrible when converted. Rather then looking at saving weight by using convertible lenses I would be more concerned with image quality, bellows length, f stop. There isn't much of a reason to use a 150 and a 180 with 45 unless you have very specific need for two basically normal 45 lenses, although the 180 is a long normal on 45. You could save weight by paring down your lens selection and replace one of them with a wide angle.

Kevin Crisp
20-Jan-2017, 14:24
If weight is critical, there are some classic small and light wide angles. The f:18 Protars, the Wollensak Ex. Wide angles, the 90mm Angulons, for example.

I am not aware of any convertible that is really a wide angle. Going from memory there was a Symmar in the 100mm or so range range that could convert to longer, but that doesn't help you and there might not be coverage for 4x5 anyway.

Dan Fromm
20-Jan-2017, 14:39
OP, I often want what's impossible but I never get it.

Second best, as has already been suggested, is an old technology w/a lens. 88/6.8 B&L, 89/6.3 W/A Wray, 90/6.8 Angulon or Optar/Raptar, 100/6.3 Aristostigmat or WF Ektar. Any of several Leitmeyr lenses. I have a tiny 75/14 Perigraphe that will cover 4x5 but it is in barrel; it can be stuffed into the front of an Ilex #3 but then you're back with size and weight. Some of these are relatively easy to find, others hard, others nearly impossible.

So you know, single cells of convertible lenses are much slower than the complete lens and most have the same coverage as the complete lens. Single cells' f/numbers range from 1.7 to 2 times the complete lens' f/number. For example, a single cell of an f/6.8 Beryl is f/13.

B.S.Kumar
20-Jan-2017, 16:21
Horseman did make a behind the lens converter for their lenses. I have no idea of its performance.

Kumar

Bob Salomon
20-Jan-2017, 16:26
Horseman did make a behind the lens converter for their lenses. I have no idea of its performance.

Kumar

Wasn't that for their 150? And it made the lens longer, not shorter.

B.S.Kumar
20-Jan-2017, 16:36
Yes, it was for the 150. I think it was a 2X. Sorry for the diversion.

Dan Fromm
20-Jan-2017, 16:38
Re the Horseman converter, I have one. Used as intended it is a 2x TC, doubles the focal length and the extension required. Users' reports about how well the TC + prime lens performs disagree.

It works as intended only with 150 mm lenses in #0 shutters. The instructions list a moderate number of 150s that will work with it.

Three parts. The first is a replacement for the shutter's retaining ring. The second is an extension tube that attaches to the replacement retaining ring. And at the rear the TC, which screws into the extension tube. To set it up, unscrew the prime lens' rear cell, remove the retaining ring, reattache the shutter to the board with the replacement retaining ring, replace the prime's rear cell, attach the extension tube and finally attach the TC.

The combined focal length -- prime lens + TC -- depends of the prime's FL and on the distance between the prime's rear surface and the TC's front surface. When used not as intended the results are quite unpredictable.

Not what the OP wants.

mdarnton
20-Jan-2017, 17:03
90mm Angulons, as well as the other focal lengths, were originally sold as triple convertibles (!!), if that is really what you want to do. Which I would not.

Read page 8 and 9, here: http://cameraeccentric.com/html/info/schneider_3.html

Mark Sampson
20-Jan-2017, 20:10
I'd look for a 100/6.3 Kodak Wide Field Ektar. Small and sharp. Or our own Kerry Thalmann has a late-production 90/6.8 Schneider Angulon for sale, and he knows his lenses; I'd buy from him anytime. Either one would let you shoot wide-angle without adding too much weight and bulk.

Jim Andrada
20-Jan-2017, 21:17
+1 on the Wide Field Ektar. Very nice lens IMNSHO

IanG
21-Jan-2017, 02:51
90mm Angulons, as well as the other focal lengths, were originally sold as triple convertibles (!!), if that is really what you want to do. Which I would not.

Read page 8 and 9, here: http://cameraeccentric.com/html/info/schneider_3.html


That's the pre-WWII Angulon which has more coverage than the later post WWII Angulon, although both were at times described as convertible, If you look the early 90mm f6.8 Angulon covers half plate at f22 while the later version vignettes earlier only just covering 5x4. I've just acquired the cells of an earlier 90mm Angulon so it'll be interesting to see the difference.

Ian

mdarnton
21-Jan-2017, 05:53
Yes, but info I can find indicates that the formula is the same and that coverage is a mounting limitation by the metal work, so converting should work the same. But I cannot imagine anyone intentionally wanting an 185 mm lens working at f/14 when there are so many great small alternatives with speeds one can actually focus at! Also, it is usually not a good thing when a manufacturer of that era says a convertible lens is good for portraits--the optimistic way to say results aren't going to be very sharp. :-)

esearing
21-Jan-2017, 06:07
My question was more regarding a wide triple convertible like Cooke made for 8x10. I have 65, 90, 135, 150/265, 180/315, 210, 250 lenses but I usually only carry 3-4 of them at any one time. Looks like I may have to opt for a 70mm-80mm and not carry the 65 and 90. I seem to use the 65 and 135 the most of all my lenses. current projects are mostly rivers and waterfalls which call for wides most of the time.

Though that Schneider Angulon 90 6.8 sounds like it would be worth experimenting with: 90, 140 (rear only), 185 (front only) - but might be hard to focus with at 185 with 4x exposue factor.

jnantz
21-Jan-2017, 06:22
esearing
you might look into making yourself a casket set full of gclaron cells.
http://www.apug.org/forum/index.php?threads/casket-sets-anyone.33629/
that way you might only have to bring 1 thing and it has everytihng you need
there have been threads here on this website about what cells you might need
and their configurations, i think some of them were kind of wide-angle-view

good luck !

Dan Fromm
21-Jan-2017, 06:53
Um, John, the shortest G-Claron is 150 mm. A single cell will be nearly twice as long. As for mixing and matching, well, the 150's cells fit a #0. 210 through 305 fit #1. 355 fits #3.

Ugly fantasy.

IanG
21-Jan-2017, 07:05
Schneider sold a sort of Casket set of Symmar cells in the late 1950's or very early 60's, it can't have sold well as you never come across thm now. I can't remember the exact details off the top of my head but have an advert for them in a BJP Almanac.

Ian

jnantz
21-Jan-2017, 08:13
Um, John, the shortest G-Claron is 150 mm. A single cell will be nearly twice as long. As for mixing and matching, well, the 150's cells fit a #0. 210 through 305 fit #1. 355 fits #3.

Ugly fantasy.

thanks dan !
i wasn't sure if they made them shorter, people love their casket sets ! :)

Daniel Unkefer
21-Jan-2017, 17:52
I remember I was in the basement of Midwest Photo, Ron Wisner was there, and Ron found some converters for his Zeiss Protars. He was elated and made a huge pile to stuff to take home. Don't remember if they were wide angles?? Anyway would be rare rare rare and 'spensive.