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    #11
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    If the 58mm number came from the rear diameter of your anamorphic lens, the good news is that because you are going to be shooting at a maximum of a 24.3mm image circle (Red Epic 4/3 Ana 5k), just about any zoom will do, regardless of front diameter. That's because the lenses you're looking at were designed for a full frame coverage of 43.3mm.

    24.3mm [RED sensor] / 43.3mm [Lens Coverage] = 0.561 * 77mm [Front Diameter of Lens] = 43.2mm [Usable front diameter that is seen by the sensor]. Basically you'll only be using the center-most part of the lens and that is the only area that needs to be covered by the rear element of the anamorphic projector lens.

    Using that anamorphic projector lens, A 70-200mm zoom will do better vignetting-wise on that image circle (see here: http://www.tferradans.com/blog/?p=13386 - it has more to do with the angle of view than the front diameter). You're also going to get a bit of a wide angle effect, so that 70-200mm will appear as a 35-100mm lens horizontally.

    One of the cheapest/nicest 70-200mm zooms out there is the 1st Generation Sigma 70-200mm, which comes native in EF. Most importantly, it has fully internal zooming and focusing. Also, based on reviews, it seems to be a bit sharper in the center at 200mm than the newer versions, which have much better corner performance (of which you won't be using.)

    If you're using a 2x anamorphic lens, you may want to shoot at 6:5 anamorphic, which de-squeezes to a 2.4 ratio. It also reduces the image circle. 6:5 on the Epic would put you at about a 22.77mm image diagonal.

    As well, the Scarlett W has smaller pixels than the Epic ( .005mm vs .0054mm). So, 4:3 on the Scarlet W would be about a 22.5mm image diagonal, and 6:5 would put you around a 21.09mm image diagonal.

    What anamorphic lens will you be using?


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    #12
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    Also, from experience, and as a warning, it may be really hard to dual focus at f2.8 with this combo.


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    #13
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    Quote Originally Posted by Joshua Cadmium View Post
    If the 58mm number came from the rear diameter of your anamorphic lens, the good news is that because you are going to be shooting at a maximum of a 24.3mm image circle (Red Epic 4/3 Ana 5k), just about any zoom will do, regardless of front diameter. That's because the lenses you're looking at were designed for a full frame coverage of 43.3mm.

    24.3mm [RED sensor] / 43.3mm [Lens Coverage] = 0.561 * 77mm [Front Diameter of Lens] = 43.2mm [Usable front diameter that is seen by the sensor]. Basically you'll only be using the center-most part of the lens and that is the only area that needs to be covered by the rear element of the anamorphic projector lens.

    Using that anamorphic projector lens, A 70-200mm zoom will do better vignetting-wise on that image circle (see here: http://www.tferradans.com/blog/?p=13386 - it has more to do with the angle of view than the front diameter). You're also going to get a bit of a wide angle effect, so that 70-200mm will appear as a 35-100mm lens horizontally.

    One of the cheapest/nicest 70-200mm zooms out there is the 1st Generation Sigma 70-200mm, which comes native in EF. Most importantly, it has fully internal zooming and focusing. Also, based on reviews, it seems to be a bit sharper in the center at 200mm than the newer versions, which have much better corner performance (of which you won't be using.)

    If you're using a 2x anamorphic lens, you may want to shoot at 6:5 anamorphic, which de-squeezes to a 2.4 ratio. It also reduces the image circle. 6:5 on the Epic would put you at about a 22.77mm image diagonal.

    As well, the Scarlett W has smaller pixels than the Epic ( .005mm vs .0054mm). So, 4:3 on the Scarlet W would be about a 22.5mm image diagonal, and 6:5 would put you around a 21.09mm image diagonal.

    What anamorphic lens will you be using?
    Dear Joshua, thank you so much for your reply, it clarified a lot of things that I really wasn't taking into account.

    To answer your question right away, I was thinking of using an ISCO Ultra Star due to the more appealing MFD (of around 5 feet, according to the seller). I was also considering a Kowa, but those seem to be a bit trickier in that sense. However, I'm not gonna hide the fact that I'm really not an expert in the matter, so your advice would be much appreciated.

    Also, after running a couple of tests with a Canon 70-200 f2.8 that I managed to get a hold of during the weekend, I came to the unfortunate conclusion that the range it covers won't be enough to achieve the kind of shot we had in mind. I have been looking into 10x and 12x zoom lenses within my budget, and I have been finding some very appealing options. The only issue with these is that they all come in C-mount, which I really haven't had any past experience with. I bought a very cheap Canon one with the intent of running some tests with it, but it's still on its way. Do you know wether it would be a good idea to go with these? How easy is it to adapt them to EF or PL? Also, I read somewhere that they can be easily used on a full-frame camera with a 2x teleconverter (which I also bought dirt cheap for test purposes), but in case that didn't work, would it be possible to use them natively at 2k resolution on the Epic utilising the Mysterium-X crop factor? I read of people doing it with S16 Zeiss Superspeeds and achieving pretty stunning results. Again, your opinion would be much appreciated.

    Thank you very much for your time, looking forward to your reply.


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    #14
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    You're welcome!

    I have an ISCO as well - not the Ultra Star, but something similar.

    A C-mount lens is probably not going to work. One, the flange focal distance (the space between the lens and the sensor) is very short. C-mount is around 17.5mm, while Canon EF is 44mm. PL is even greater, at 52mm. Red does has an interchangeable mount system with a flange of 27.3mm, but it doesn't look like anyone makes a C-Mount interchangeable mount. The reason is because a greater flange distance in general means that any normal adapters out there (like this one: https://www.amazon.com/Fotodiox-Adap.../dp/B003EAY5S6) don't hit infinity focus, and seem to be more used for macro purposes.

    I don't have much experience with C-Mount lenses, though, so there may be some odd 2x teleconverter combo out there that would work. However, the old Canon TV zoom lenses aren't really the sharpest things out there. Add a 2x teleconverter, plus the softening from the anamorphic, and the image might be unacceptably soft.

    As for the second reason - are you trying to get a much wider angle - is that why a 70-200 range won't work? That's almost going to be impossible with the combination (Ultra Star + C-mount zoom) you're looking at. One, the angle of view will quickly see the inside of the anamorphic lens. The ISCO Ultra Star (the separate anamorphic attachment) is a long lens, and any wide angle is quickly going to see the inside of the lens. In photography, you'll often see wide angle filters that are thinner by a millimeter. The Ultra Star, however, is somewhere in the neighborhood of 10cm or greater, so that really narrows the angle of view that will fully see through that. There are other anamorphic projection lenses that will give you a wider angle of view, but it isn't going to be super wide. You might want to look at that calculator that I linked again - it will give an approximation of when vignetting will began, based on the type of anamorphic attachment and the focal length of the lens.

    On top of that, small format super zooms typically have a large front element, whether they are designed to cover a B4 (11mm diagonal), Super 16 (14.54mm diagonal), or 1" sensor size (16mm diagonal - which is most likely what the Canon you bought covers). That is most likely for the wide side of things, but it will cause vignetting attaching it to a anamorphic lens, since (unlike a full frame lens) you now are going to be using the full diagonal of the front element. Based on the lens, zooming in may help with that vignetting, but that might put you right back where you started from.

    If the 2k resolution crop on the Epic is an option, you may just want to use a Blackmagic Cinema Camera or Pocket, as the end results might be similar, but the Blackmagic option would be much cheaper.
    Last edited by Joshua Cadmium; 05-23-2017 at 11:13 PM.


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