Great Taking Lenses for FF/FX Iscorama?

[tommykristensen]

I bought an Iscorama back in february, and didn't have much time to fiddle around with it before I send it for a rehousing at Van Dieme. Now its back - I ripped it out of the box - and tried it with a bunch of lenses and the 5DmkIII. And to my surprise, the Iscorama is pretty picky when it comes to taking lenses...

 

I've tried it on:

 

Canon 50mm f/1.8: Not usable, Vignettes on all apertures.

Helios 44-2 58mm f/2: Somewhat usable. f/2 to f/2.8 vignettes a little, but can be used.

Canon 24-70mm f/2.8: Somewhat usable. f/2.8 to f/13-ish is fine @70mm

Samyang 85mm f/1.4: Somewhat usable. f/1.4 to f/2.4 is fine - after that vignetting gets worse for each step

 

Canon 90mm TS-E f/2.8: Works perfekt

Jupiter 37A 135mm f/3.5: Works perfekt.

Tair11 135mm f/3.5: Works perfekt

Jupiter 21 200mm f/4: Works perfekt

 

I guess that lens build, front diameter, adaptor use etc, has a great say - but does anyone know of lenses around 45mm - 70mm that works perfect - preferably through all or most apertures? Filter thread close to 58mm (back thread on rehoused Isco) being a huge bonus.

[dahlfors]

Are you talking about hard vignetting (full black in corners) or soft vignetting (faded out)?

 

I use a full frame Nikon D800. I get a tiny bit of hard vignetting with my Nikkor AF-D 50mm f/1.4 with the pre-36 Iscorama. If you crop away the sides to achieve 2.35:1/2.40:1 instead of 2.66:1 the hard vignetting doesn't matter. There's quite a bit of soft vignetting as well at apertures around f/1.4-f/2. 

 

I got two Dog Schidt Optiks FF58 (modded Helios 44 lenses) which does not have any hard vignette at all on my full frame Nikon D800. 58mm seems to be the perfect focal length for wider shots whilst avoiding vignette.

 

Same goes for 85mm f/2 Nikkor AI-S, no vignette. I also have a Nikkor 105mm AI-S and a Nikkor AI 200mm.

 

 

The taking lenses I find the best for the Iscorama are the DSO FF58's and the 85mm AI-S Nikkor. I very rarely use any other taking lens.

 

All of the Nikkors have 52mm filter thread, and I haven't found any issues with any of these lenses at any apertures besides the vignetting on the 50mm Nikkor.

 

I've also tried the dirt cheap 50mm f/1.8 E-Series Nikon lens. That one didn't seem to hard vignette with the Iscorama, and there is not as much soft vignette as on the 50mm f/1.4. There's some issue with my sample of that one though, it doesn't focus properly on infinity so I haven't really used it with the Iscorama except for checking vignetting. I'm happy with the FF58's, so I don't think I'll waste any time on getting another E-Series.

[tommykristensen]

Weird - my DSO 58mm has hard vignetting at f/8-16 - and softer ones from f/2.8 to 8

[Rob Bannister]

hmm I'll have to try stopping down my DSO lens Ive also heard the older nikon 50 1.8 is a good choice but you are risking going wider then 58mm with that one.

[tommykristensen]

[tommykristensen]

Above the rehoused Iscorama. The new rear filter thread is now 58mm - aligned/levelled with the end of the metal housing - and i think that is whats giving my trouble. On the original Iscorama, the Iscoramas rear element was nested inside the taking lens - and much closer to the "glass". Maybe a pancake 50mm-ish would be the solution?

 

Tony Wilson - have you had any vignetting on 50mm on your rehoused Iscos?

[tony wilson]

optic to optic distance is your problem.
you will have to dump your helios find a 2nd hand camera shop and try some different recipes should give slightly different edge results.
even the 50mm on a normal isco gives white vignette flare if you point it into a bright light that is why 55mm-60 is better.

[dahlfors]

The Nikkor 85mm f/2 AI-S that I mentioned earlier could provide a good match for your rehoused Iscorama. I usually have that one quite far away from the Iscorama, since removing one filter ring would make the rear of the Iscorama touch the glass of the taking lens. Here's more info + picture of the 85mm:

- MIR: http://www.mir.com.my/rb/photography/companies/nikon/nikkoresources/85mmnikkor/85mm2.htm

- Ken Rockwell: http://www.kenrockwell.com/nikon/85f2ais.htm

 

Other than that I like it paired with the Iscorama, it is one of the sharpest lenses I have for my D800, an excellent portrait lens.

 

 

And Rob: The earlier suggested Nikon 50mm E Series f/1.8 can be fitted nicely on an Iscorama with normal housing, since it has its optics very close to the filter thread: http://www.kenrockwell.com/nikon/images1/50mm-series-e/KEN_5168-1200.jpg

 

They can be found very cheaply as well. Note that there exists a few different versions of them, and the one I linked above is the one with the optics closest to the filter thread. The E Series version with a silver colored aperture ring has its optical elements further away from the front of the lens, and I assume you'll be getting vignetting with that version due to optic to optic distance.

[tony wilson]

you need to take care with some pancake lens that is a lot of weight for a screw thread to take...

your lens is now heavier than a isco 42 i sold one a few years ago the guy dropped it on the floor within a week from playing with pancake lens..nothing wrong with um it is just your set up now requires much more care because of front weight.