Ideal focal lengths for anamorphic with full frame and MFT (M43)

[burrencrawler]

Hi guys,

            I am new to the anamorphic thing. I have just bought a Kowa 16H (2x) but I am waiting for the lens clamps so I have not used it yet, very exciting......One thing i wanted to know is what are the minimum & maximum recommended focal lengths for use with a 5D and also for MFT? as i have 5D mk II,III, GH2 and BMPCC that i would like to use this system with. This way I will know what lenses in my artillery I can use for either full frame or MFT format anamorphically, and I can start ordering the right diameter clamps for the recommended lenses now to not waste any more time.

[Chris Elkerton]

As far as full frame goes, you will avoid vignetting completely at 85mm. As long as you don't stop down too much, you can go as wide as 58mm in my experience.

[burrencrawler]

Cool Chris, and for M43 anyone?

[dhessel]

m43 is roughly a crop factor of 2, I believe. So take the focal lengths for the 5D and divide by the m43 crop factor. 29mm wide open and 42mm stopped down. 

[JBraddock]

It's 35mm for M43. But I am not sure if it is the case regardless of the taking lens. I bought a Carl Zeiss 35mm for that purpose but I have yet to try it. It is being serviced now.

[burrencrawler]

Thats interesting, why is the Helios 58mm lens the 'lens of choice' if the limit (even stopped down) is 42mm.

This does not make sense to me Dhessel.....Or does that mean that 58mm is OK because its over 42mm?

Also does that mean that instead of a Helios 58 44M one could also use a Jupiter 3 or Jupiter 8? (both 50mm).

[JBraddock]

My guess is that anamorphic shooting already gives a wider field of view and Helios 58 seems to be good match for many anamorphic lenses. I haven't used one though.

[burrencrawler]

OK ,so some are saying for M43 the minimum focal length is 35mm, others 42mm. There is a big difference between these (between 70mm to 84mm equivalent of M43). Can someone confirm which is right please? As i said I just want to know all these BEFORE I go start ordering lenses that may not turn out to work well with the 16H Kowa anamorphic lens. Thanks

[JBraddock]

35mm is what Andrew says in this guide. As I said, I haven't tested it yet.

[Julian]

It depends on the lens design... some 35mm's may work, some may not. Not all 35mm's are equal. For example, a big fullframe 35mm f/1.4 (like Canon/Nikon/Samyang) probably will give problems, since it has a huge front element.

 

Also lenses with a front element that is protruding into the lens might show more vignetting, since the anamorphic adapter can't get close enough. It's trial and error, simple as that.

 

My Kowa for B&H 2x works fine on my GH2 + Minolta 35mm f/2.8. But if I combine it with a 14-42mm Panasonic kitlens, i'd have to zoom in to 42mm probably.

[dhessel]

I have seen that the min focal on FF is about 75mm. That is somewhat rough based off a zoom lens I used to have. Since 85mm primes are more commonly used on FF many may say that the min focal is 85mm on FF. You can go much lower and still have a usable image when shooting wide open. I have used a Helios 44 which is 58mm on a FF 5DmkII. Wide open there is vignetting but it is a very soft darkening on the outsides, kind of nice actually. When stopped down you can clearly see the adapter on the edges and the edges must be cropped. 

 

Since a 2x gives you a 3.56 aspect ratio when shooting HD you can crop that down to a more normal 2.67 or 2.35 and remove most of the vignetting. This crop is may not enough to remove the vignette completely on the Helios at 58mm however. Since you have the MKII and III be sure to use the ML hack and shoot raw with a more square ratio, 1.175:1, 1.2:1, 4:3. I shoot 1472 x 1250 on my MKII which is continuous with MLV and audio at a 2.35 aspect when unsqueezed. 

 

I am hoping that at some point BM will add a 4:3 mode, I would be very happy with a 2048 x 1556 option for my BMCC. Considering their track record on updating their cameras, I am not optimistic that that will happen any time soon. 

[itimjim]

Depends on the anamorphic and the taking lens. My Bolex 16/32/1.5x is usable with Canon 28/2 on MFT (although vignette at infinity on GH2 with multiaspect sensor). My Kowa Prominar 2x is best with the FD 35/2.

 

28mm is my favourite FL on MFT with anamorphic, 35mm + 0.71 speedbooster on BMCC.

[burrencrawler]

Iti, Your Kowa Prominar is best with the FD35/2......and its not too wide? what F-stops?

 

and when you say "28mm is my favourite FL on MFT with anamorphic, 35mm + 0.71 speedbooster on BMCC."

what do you mean, and what is FL?

[Christina Ava]

there is no golden rule because sometimes each lens is a bit different than specs.

usually you need over 85mm for full frames, so that it wont vignette.

this is the focusing distance test

when you get the adaptors go and test how close you can go without a diopter and then measure it with a tape.

just go as close as you can without losing focus, see if its an arms lenght or more then try to visualise that gap for future use

with the diopters do the same later on...

for maximum again you have to test and see it on the video, for example my setup for some reason cannot focus to infinity.

[Rob Bannister]

It has to do with the stretch factor. So at 1.5X you can get away with around 50mm on full frame and at 2X usually around 75mm-85mm. This is on most lenses Ive seen that us mere mortals can afford...the ones that are not intentionally built to be something crazy like a 22mm or 35mm with 2X stretch that would be one lens block.

 

It really helps to think about what you are really asking for out of that lens like a 35mm with a 2X stretch is around a 15 or 16mm horizontally....think about shooting with the 22mm. Ive always been interested in shooting with the 35mm 2X lomo..if anyone has one around Vancouver ;)

 

 

there is no golden rule because sometimes each lens is a bit different than specs.

usually you need over 85mm for full frames, so that it wont vignette.

this is the focusing distance test

when you get the adaptors go and test how close you can go without a diopter and then measure it with a tape.

just go as close as you can without losing focus, see if its an arms lenght or more then try to visualise that gap for future use

with the diopters do the same later on...

for maximum again you have to test and see it on the video, for example my setup for some reason cannot focus to infinity.

[silvertonesx24]

From my experience, 2x requires about 85mm FF. And being that you're getting 2x "back" into the image, you're really getting about a 43mm field of view equivalent. So I like to shoot anamorphic at 100-135mm full frame, as I then get nice bokeh due to the longer shot scale.

 

I don't really see too much value in shooting really wide field of view anamorphic.

[Emanuel]