Relative Focal Length, Angle of View, and CCF Chart

Glad you like it, tmj!

Yeah, part of the reason I came up with this chart was to push the idea of a Cinema Crop Factor. The "crop factor" is relevant only for stills cameras, and really has no bearing on cinema. The Cinema Crop Factor attempts to relate a given camera system to the prevailing standard of 35mm cinema film.
 
Hi Barry,

I hate to drag this out further, and I know it must be completely doing your head in to relentlessly answer these questions, but I have a question regarding the (eek! I hate to say it) "crop factor" of GH1 in 16:9 movie mode, compared to AF100.

Some people on another forum swear that the GH1's real crop factor (as related to full frame compensated to 16:9) is closer to 1.85x rather than the 2.0x which is often touted, due to i) the crop required in the 5Dii sensor to achieve 16:9 and ii) the fact that GH sensor is larger than 4/3 to allow it to make 16:9 image larger than it would otherwise be. The point being made is that a given lens on the GH1 camera exhibits a wider angle of view than on the AF100.

Can you confirm of squash this notion for me please?
 
The GH1's sensor (and the GH2, for that matter) are slightly oversized and, yes, the crop factor is less when in 16:9 mode on a GH1 (or GH2) as compared to the 5D Mark II. Panasonic hasn't, as far as I know, released the exact true width of the GH1/GH2 sensor, but from pixel calculations we think it's using an area of 18.9 x 10.6 or thereabouts. That is bigger in width than the 17.3x13 size that is commonly used for Four Thirds sensors, and that's the reason the "crop factor" of movie mode is less than the "crop factor" of stills mode.

The AF100 doesn't use the same sensor or the same sized sensor as the GH1/GH2. Its 16:9 image is made from a slightly smaller patch, it uses 17.8 x 10mm. As such, the "crop factor" is closer to 2.0 as compared to a 5D, and the GH1/GH2 do exhibit a slightly wider field of view than the AF100 does. It's a difference of about 5%.
 
Great. Thankyou. I still wonder where it would squeeze in on that lovely chart you made up.

Calculations by others, based on the Panasonic diagrams, are for a 1.85x crop from 5D2's 16:9 movie mode, making 27mm the "standard" lens.
 
any way great work by barry green once again. i am not questioning your work at all, you calculated by taking measures from panasonic's given manual. but with my curiousity i am asking this. if AF 100's sensor size is 17.3*13 mm then it can record the 16*9 image size in 17.3mm*9.731mm only. how it can record in 17.8*10mm. if i am compleately wrong about math and cameras technology, please excuse for my ignoranse. if possible clarify this to me Mr Barry Green.
thanks for your valuable chart work.
 
So, essentially this is saying if you want a normal viewpoint (the normal category obviously), then you would need a 25mm lens, correct? I'm having trouble figuring out what size still camera lens I would purchase to use on the Af100..

I'm new to the whole lens thing, but I am going to buy the af100 in probably six months (unless I opt for something else, or hear of a better option).

Any help would be really appreciated. Thanks!
 
Barry_Green said:
The Cinema Crop Factor was designed around the standard 35mm cinema frame, and in that scenario the AF100 is 1.19...
Click to expand...
Do you all agree that academy aperture is handy starting point for comparison?
Hardly no movies are shot in that format in this millenium and there's no digital cameras using that format.
Maybe some real world physical object that is in use would be easier to understand?
 
This chart rocks, Barry.

After reading your book I feel like I'm talking to a celebrity whenever you post here, man.

Thanks for helping us out so much. Really appreciate it.
 
This is a very useful chart.

But the 1/4 stop DOF difference between M43 and Academy is a little misleading as Academy hasn't really been the standard for about a decade now. Super 35 is, and the other digital cinema cameras are based on the Super 35 frame size. So it would have been more useful to compare M43 with that. Also, even though M43 is extremely close in size to even Super 35, when you look at tests like the ones bellow you can't help but see that in practical applications the DOF seems much shallower in Super 35 than in M43.


 
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Wasn't Batman Begins shot Academy 35? And Black Swan S16? People get far to hung up on all these standards.

It should be noted that the speedbooster is giving the AF100 the S35mm field of view and DOF from still lenses, so I imagine on the various multi mount PLs out there you could possibly achieve a field of view that's greater than S35 when using said lens via the Speedbooster
 
XSVpro said:
Wasn't Batman Begins shot Academy 35? And Black Swan S16? People get far to hung up on all these standards.

It should be noted that the speedbooster is giving the AF100 the S35mm field of view and DOF from still lenses, so I imagine on the various multi mount PLs out there you could possibly achieve a field of view that's greater than S35 when using said lens via the Speedbooster
Click to expand...


Err, Batman Begins as pretty much all Nolan's recent films was shot anamorphic. Yes, anamorphic uses the academy frame, but it's a totally different animal from shooting plain Academy.
S16 to me is an artistic decision on pair with choosing to shoot something on video, like they did for example for 28 Days Later. They obviously didn't care for quality.
Nobody is saying that the DOF from M4/3 is not shallow enough. I just said that comparing M4/3 to Academy instead of comparing it to the standard which is S35 is as useful as comparing it to S16 DOF. It only serves M4/3.

Regarding the miraculous speedbooster, it seems it is not so miraculous after all. Initial quality tests look pretty meh to me.
 
What's tests Adam? I've seen Eoshd and James Millers tests, the white paper m43 test shots looked better too. What is it you don't like about the speedbooster?
 
Adamsenoj said:
Nobody is saying that the DOF from M4/3 is not shallow enough. I just said that comparing M4/3 to Academy instead of comparing it to the standard which is S35 is as useful as comparing it to S16 DOF. It only serves M4/3.
Click to expand...

The difference between m43 and Academy projection aperture (what you actually see in a theater) is 10%; m43 and S35 projection aperture 20%. It's something, but it's not a lot.

S35 is definitely the Hollywood standard at this point, but only recently and not globally, so I wouldn't dismiss the comparison to Academy. Here's the top 25 box office of 2012 and what they shot on:

The Dark Knight Rises Anamorphic 35
The Hunger Games Anamorphic 35
Skyfall Anamorphic 35
The Twilight Saga: Breaking Dawn Part 2 Anamorphic 35
Snow White and the Huntsman Anamorphic 35
Brave Animation
Madagascar 3: Europe's Most Wanted Animation
Dr. Seuss' The Lorax Animation
Wreck-It Ralph Animation
Ice Age: Continental Drift Animation
Hotel Transylvania Animation
21 Jump Street Super 35
Marvel's The Avengers Super 35
MIB 3 Super 35
Taken 2 Super 35
Safe House Super 35
The Bourne Legacy Super 35
The Vow Super 35
The Hobbit: An Unexpected Journey Super 35
The Amazing Spider-Man Super 35
Prometheus Super 35
Magic Mike Super 35
Lincoln Super 35
Django Unchained Super 35
Ted Super 35
 
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