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?
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?
No you buy a wide angle lens.
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.
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...Originally Posted by Luis-F-S
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.
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.
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.
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.
Yes, it was for the 150. I think it was a 2X. Sorry for the diversion.
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