fates
Active member
I'm not discounting the two above posts (and their very knowledgeable sources) but a couple important points re: rack focusing with the Iscorama:
1. The focus throw is ridiculously long on the lens. The helicoid has a very fine pitch and shifts focus only slightly with each quarter turn. Compaired to a modern Canon lens (which has a tiny focus throw) it's like sailing around the world 2x
2. The rear lens needs to be very well built and not rotate/wobble in EF adapter/bend due to plastic construction (*ahem Nikkor 50 1,8*). .5mm of shift will result in unusable warp of the image due to the anamorphic angle changing during a take with a pull.
3. Your chances of finding a perfect, low drag, and smooth turning Iscorama these days is slim. They were pretty stiff from the factory as far as I've seen. That said, to re-lube the helicoid on these with a thinner lubricant to make turning easier, the front element would need to be opened. Because alignment is so hyper critical on these lenses (and many of the later ones made from plastic) I think a tech is going to be hard pressed to reassemble perfectly to maintain the razor sharpness these things have.
My advise is that if you want an anamorphic lens, and can find a Isco (at a reasonable price), do it. When a shot calls for a true, deep rack focus.... use a different lens and crop it. Then go back to your Isco.
One other note, I found a .75 diopter that came with my old Krasnogorsk-3 kit. Not quite the .5 but a different focal length than the 1 for sure.
1. The focus throw is ridiculously long on the lens. The helicoid has a very fine pitch and shifts focus only slightly with each quarter turn. Compaired to a modern Canon lens (which has a tiny focus throw) it's like sailing around the world 2x
2. The rear lens needs to be very well built and not rotate/wobble in EF adapter/bend due to plastic construction (*ahem Nikkor 50 1,8*). .5mm of shift will result in unusable warp of the image due to the anamorphic angle changing during a take with a pull.
3. Your chances of finding a perfect, low drag, and smooth turning Iscorama these days is slim. They were pretty stiff from the factory as far as I've seen. That said, to re-lube the helicoid on these with a thinner lubricant to make turning easier, the front element would need to be opened. Because alignment is so hyper critical on these lenses (and many of the later ones made from plastic) I think a tech is going to be hard pressed to reassemble perfectly to maintain the razor sharpness these things have.
My advise is that if you want an anamorphic lens, and can find a Isco (at a reasonable price), do it. When a shot calls for a true, deep rack focus.... use a different lens and crop it. Then go back to your Isco.
One other note, I found a .75 diopter that came with my old Krasnogorsk-3 kit. Not quite the .5 but a different focal length than the 1 for sure.
