FS7: Zeiss Milvus
- Thread starter Liam Hall
- Start date
Ben Scott
Veteran
Not bought a speedbooster for this but probably will down the line purely for more options. I have one with no electronics for my older lenses.
That said, I know it sounds silly but I really like the S35mm frame and am not trying to ape a Vista Vision look and the lenses are plenty fast enough, and also I don't want more glass between this and the sensor.
Used it au natrel for interviews yesterday and will post a screengrab later. Worked well. I think it makes sense for me to have the 28mm next because I do so much around 28-35mm.
That said, I know it sounds silly but I really like the S35mm frame and am not trying to ape a Vista Vision look and the lenses are plenty fast enough, and also I don't want more glass between this and the sensor.
Used it au natrel for interviews yesterday and will post a screengrab later. Worked well. I think it makes sense for me to have the 28mm next because I do so much around 28-35mm.
Grug
Veteran
If TLS or PS Technik could pull the glass out and put them in a proper housing with PL-mounts, manual iris, and proper focus direction, I'd be perfectly happy to jump on them.
However a CP.2-style housing from Zeiss adding that lovely 14-blade iris from the CP.2s would certainly add a little something extra though.
Grug
Veteran
Oooh... the 28mm would become a 19.5mm f/0.95 with a Speedbooster! That would certainly open up some really interesting creative possibilities!
Robert John
Member
Hi Grug, I'm pretty sure a speed booster on a 28mm would make it a 29.96mm the speed booster has a 1.07 crop factor. Or maybe I'm mistaken.
Bern Caughey
Veteran
28mmx0.71=19.88mm
Robert John
Member
This is off the description on B&H:
The Speed Booster condenses light from the lens and projects it onto the APS-C sensor allowing the sensor to utilize all of the lens' light and effectively reduces the crop factor of and APS-C E-Mount camera from 1.5x to 1.07x, producing a full-frame angle of view with an APS-C sensor.
On Metabones FAQ they say:
Speed Booster® physically reduce focal length by a factor of 0.71x and the APS-C camera body reduces FoV by a "cropped factor" of approx 1.52x, so the 35mm equivalent focal length (cannot be overemphasized this ia a FoV measure) of the combined system is approximately 1.08x.
The speed booster is 0.7 but you have to add back in the crop factor of the sensor of the camera you’re using which then makes it 1.07-1.08.
Lenilenapi
Carbonite Member
"Crop factor" is a really confusing concept and best eliminated from the vocabulary as the question always is "compared to what?" and 2 people may be talking about completely different things. . The result is a ridiculous sentence like "which then makes it 1.07-1.08 " - huh? Best to not use it. The question is when using a full frame lens with a speed booster on an APS-C sensor you get the field of view of a lens .71 x's the full frame lens. Hence - 28mmx0.71=19.88mm.
So a full frame lens using speed booster at f2.8 is like a 20mm lens at f2.0 on an FS7 without speedbooster. Stay away from crop factors they will rot your brain.
So a full frame lens using speed booster at f2.8 is like a 20mm lens at f2.0 on an FS7 without speedbooster. Stay away from crop factors they will rot your brain.
egproductions
Veteran
Despite S35 being the industry standard, product specs are always compared to 35mm (full frame) equivelents FOVs
Robert John
Member
So are you say that I should ignore those numbers that Metabones has put in their faq. I will have a field of view of 19.88 on a 28mm lens. I was under the understanding that the speed booster brings the field of view back close to the original mm of the lens on a s35 sensor. Didn't realize that it gives a wider field of view. Everything I have read has been the opposite.
This is an example of what I have been reading From DPreview:
Adding the speed booster to a 50mm F1.4 lens turns it into a 35.5mm F1.0. But, since we’re then going to mount it on an APS-C camera, we have to multiply these numbers by the camera's 'crop factor' if we want to compare this lens-plus-adapter combination to a full frame camera. The end result is a 53.25mm equivalent lens that gives the same depth-of-field as an F1.5 lens would on a full frame camera.
This is confusing. I come from full frame photography. This is all new to me. I’m use to putting a 24mm lens on my nikon and it being a 24mm field of view.
My question is, if I mount a 24mm nikon lens with speed booster on a FS7 will it look identical as looking through my Nikon D5 with same lens? I’m very interested in buying the Milvus lenses for my cameras. I hope I’m making sense here.
Lenilenapi
Carbonite Member
As I said before unless everyone is on exactly the same page when they use the word "crop factor" you can have conversations and arguments that just make no sense so a lot of people try to stay away from it and I will do that here. You are however missing the concept of the speedbooster by overcomplicating it.
Its really much simpler . It just has a lens that squeezes the image that would normally be a on full frame sensor down to the size of an APS-C sensor. I think its just called a focal reducer. Thus for a 50mm lens you get the same field of view on an APS-C sensor that you would normally get on a full frame sensor.
That's it. Now if you weren't using a speedbooster on an APS-C camera you would need a 35.5mm lens to get that same field of view 50 x 0.71. So a 50mm on a speedbooster is like shooting with a 35mm lens on an APS-C sensor. The math is different for a micro 4/3 lens.
The secondary gift is that because you are concentrating the light into a smaller space you get more of it and more exposure. Hence the idea that you get an extra stop of light. A f2.8 on a speedbooster acts like an f2.0 on an APS-C sensor.
Don't overcomplicate it. Personally I find both the b&H and the metabones description confusing as soon as they start talking crop factor.
Its really much simpler . It just has a lens that squeezes the image that would normally be a on full frame sensor down to the size of an APS-C sensor. I think its just called a focal reducer. Thus for a 50mm lens you get the same field of view on an APS-C sensor that you would normally get on a full frame sensor.
That's it. Now if you weren't using a speedbooster on an APS-C camera you would need a 35.5mm lens to get that same field of view 50 x 0.71. So a 50mm on a speedbooster is like shooting with a 35mm lens on an APS-C sensor. The math is different for a micro 4/3 lens.
The secondary gift is that because you are concentrating the light into a smaller space you get more of it and more exposure. Hence the idea that you get an extra stop of light. A f2.8 on a speedbooster acts like an f2.0 on an APS-C sensor.
Don't overcomplicate it. Personally I find both the b&H and the metabones description confusing as soon as they start talking crop factor.
Robert John
Member
Got it, thanks for that explanation
Ben Scott
Veteran
Crop factors and FF35 being the benchmark makes me sad 
Completely off topic but in the past I had several Directors say they wanted to shoot 'full frame only' in order to be more 'cinematic' and then we are shooting vox pops or interviews. It's like a perfect storm of rage-inducers. Agh!
Completely off topic but in the past I had several Directors say they wanted to shoot 'full frame only' in order to be more 'cinematic' and then we are shooting vox pops or interviews. It's like a perfect storm of rage-inducers. Agh!
Nirv
Carbonite Member
Isn't someone supposed to say 50 is a 50 is a 50 at this point?
Not sure why this subject always seems to get the hackles up, it's not surprising for a stills photographer and a cinematographer to have different terms of reference for lens FOV, that is, what a 50mm looks like to them. It's impossible to discuss lens FOV without determining a datum and that very often involves words like 'crop' and 'factor.'
@Ben, did you ask those directors if they would mind if you used a wider faster lens instead? Would they have understood?
Not sure why this subject always seems to get the hackles up, it's not surprising for a stills photographer and a cinematographer to have different terms of reference for lens FOV, that is, what a 50mm looks like to them. It's impossible to discuss lens FOV without determining a datum and that very often involves words like 'crop' and 'factor.'
@Ben, did you ask those directors if they would mind if you used a wider faster lens instead? Would they have understood?
Liam Hall
Veteran
Crop factor is an amateur term. Professionals use ANGLE of VIEW.
Grug
Veteran
Haha, I had literally typed out half of that particular reply, but then I saw that Robert said that he'd 'got it' from Leni's post, so I abstained
