RED, IMAX, Medium Format, 2.0 extenders

[Peter Osinski]

VistaVision 36 x 24mm - 43mm diagonal
IMAX 70mm x 48.5mm - 85mm diagonal
645 format - (roughly) 54x40mm

Red has planned a FF, 645, and 617 model (unless they have been scrapped) and there are rumors of an IMAX style digital cinema camera coming from panavision. I like shooting in different formats or at least having the option too so I will likely be purchasing either canon cine primes, cp2's, zeiss zf's, or rehousing nikon g primes for my lens collection. Now this will cover me through full frame but what about these larger formats? If I got zeiss zf's or cp2s in nikon mount could I simply add a 2x extender to give myself medium format primes that will be 2.8-5.6 depending on the lens? Is there any reason this wouldn't work?

 

[Peter Osinski]

anyone?

 

[David Mullen ASC]

I would just worry that simply using extenders to make a lens fill an IMAX-sized sensor area would defeat the purpose of shooting in a higher resolution format, if the lenses aren't sharp. I would think you'd be better off with medium format lenses designed for an area that large.

That prototype Panavision camera may have a sensor closer to vertical 5-perf 65mm (Super Panavision / 52mm x 23mm) rather than horizontal 15-perf 65mm (IMAX / 70mm z 52mm). I don't know, the rumors tend to say "70mm" not "IMAX" in sensor size. In fact, the shape of the prototype reminds me of the Phantom 65.

 

[Peter Osinski]

Well David I understand your concern and that was the reason for this thread. There are a few things I was trying to take into account.

1. Larger Sensor doesn't necessarily mean higher resolution. I'm not talking about film here, just the evolution of digital.
2. I can always rent medium format glass if I need to but I'm trying to find the best set to invest in that would cover me in most circumstances. If I purchase zeiss zfs I will have a set of f2.8 - f1.4 lenses that I can use 36x24mm Full Frame, Epic Dragon, Epic-x, Super 35, micro 4/3 and smaller while still having the option to use an extender if I need to.

I have never really used extenders so I didn't know if there is a significant quality loss. Zeiss Lenses are sharp, more than sharp enough for even RED 5k, so I was hoping that the resulting IQ loss wouldn't be so significant that they would be unusable. Am I wrong?

I would like to shoot larger formats with lenses I own rather than rent if that eventually becomes an option but building a set of medium format primes doesnt seem very practical.

 

[Nick Morrison]

Generally speaking, an extender is going to degrade your optical performance. It's also not guaranteed to DOUBLE your image circle. I can't imagine a 50 1.4 with a 2x extender becoming a 100 2.8 that covered Medium Format. That's a big leap in image circle.

Even though Medium Format lenses "sharpness" is a tick below 35mm full frame lenses, their image circle is what you need, and as David says, they are DESIGNED for that format, and will look better.

Besides....the time is ripe to collect Medium Format lenses. They are relatively cheap right now, IMHO.