GH4 GH4 4K crops....

[Thomas Smet]

so is 1.62 the magic multiplier I use? 100mm on naked gh4 = 162mm "FOV"? (I know it doesn't change the actual physical lens mm, just looking at field of view)

If you are comparing to 4-perf s35mm film then yes. If you are comparing to actual s35mm cameras out there then the value will vary. What particular camera are you interested in comparing to? If you have a desire to match s35mm what camera do you have in mind? Beyond that there is really little reason to even worry about all this stuff.

I only used 4-perf s35mm to make our discussion easier. I also used it because it is technically the s35mm film standard although no actual digital cameras use it. None of those s35mm ever bother saying they have a 1.1x or 1.001x crop factor. They just all refer to themselves as s35mm size sensors even though they all slightly vary.

 

[wwjd]

just comparing to itself: GH4.

If I owned a 135mm lens, it would have x FOV. What would FOV of my 100mm be on naked GH4 C4k? How to reach x FOV?

I'm marking my lens where to set the zoom to match CINE LENS fov: 18 24 35 50 85 135 like that

 

[wwjd]

anyone reading along wondering about sensor size differences, this is it:

 

[Thomas Smet]

just comparing to itself: GH4.

If I owned a 135mm lens, it would have x FOV. What would FOV of my 100mm be on naked GH4 C4k? How to reach x FOV?

I'm marking my lens where to set the zoom to match CINE LENS fov: 18 24 35 50 85 135 like that

I'm not sure I understand the question. If you are not comparing a s35mm camera then why do you care what the crop factor is? 100mm on m43 is 100mm on m43. If one camera has a SB and one does not the difference is 0.64x just like the SB XL says it is. 135 x 0.64 = 86.4mm. Your naked GH4 with the 50-100 would need to zoom to around 86.4mm. If you are talking about the Sigma 50-100 f1.8 lens then there just happens to be a marking for 85mm. Just Go a tiny bit past that marking and you should be good. I'm talking a sliver past the marking.

 

[wwjd]

Thomas, I think I was cross breeding terms about things I was unsure of.... I'm saying CROP but in the end only seeking FOV of cine lens... I assumed crop knowledge was how to get there.

Here's what I have learned NOW: (maybe this will help others too)

- crop amount is simply different on the various sensors.
- mm focal length is INSIDE THE LENS, and never changes via crop (this number is NOT "FOV" which I was kinda reading it as, and is sorta related)
- Field Of View FOV (how wide) however, IS what changes on same lenses with different sensor crops
- SB .64 brings GH4 C4K pretty close to s35 (movie standard size) so I don't need to convert anything when using the SB 64

Yes, I have the Sig50-100 and plan to do exactly that: little past 85, no SB, to get 135mm FOV

Again, thank you for you patience as I slowly came to grips with all this great info!
Please let me know if I got anything wrong there. I enjoy growth.


Since I just want to get the feel (visual feel of CINE FOV) I don't have to worry about crops, just knowing the SB .64xl gets very close to s35/Alexa, and I am good to go!
Then end goal is to know how to set my Tokina 11-16, Sig 8-35 & 50-100, to cover the following CINE FOV: 14 18 24 28 35 50 85 100 135
and looks like 135 is the only one I was missing. Cool.

(but I am STILL eyeing the Rokinon 6 lens cine set)