GH2 crop factor 1.86x or 2x ?

Neither. Well, that's not exactly true. A lot of people compare 4/3 to full frame (5Dmk2), which is wrong because typically movies are not shot full frame. For video, you don't want to compare to full frame. For stills, full frame is okay to compare, but not for video. The 5D is the exception, not the rule. We're talking about video here, so you start with Super 35 as the standard, as it's been for years.

It's 2.1x when compared to a full frame sensor like in the 5Dmk2. I don't know where the 1.86x comes from. Here's a list of crop factors when 4/3 is compared to different cameras:

Super 35 Film 1.4x
Super 16 Film 0.7x
Red One/Scarlet 4K 1.3x
Red Epic 5K 1.5x
Sony F3/F35/FS100 1.3x
Arri Alexa 1.4x
Canon 5Dmk2 2.1x
Canon 7D 1.3x

A lot of people compare 4/3 to full frame (5Dmk2), which is wrong because typically movies are not shot full frame. For video, you don't want to compare to full frame. For stills, full frame is okay to compare, but not for video. The 5D is the exception, not the rule. We're talking about video here, so you start with Super 35 as the standard, as it's been for years.

Try the Abel Cine FOV calculator: http://www.abelcine.com/fov/
 
Actually, I think it's worse. Two-point-two something. Perhaps you've got a math-guy type friend who can crunch the numbers. All the sensor size measurementa are at the B&H web site.

GH2 -- 17.3 x 13.0 mm
5D mark 2 -- 36 x 24 mm

For a better answer we'd want the 16 by 9 viewing area factored in.
 
Well I think they just use the horizontal measurement. 36/17.3=2.081 so it's actually not as bad as 2.1. If you use the vertical measurement it's 1.85. Maybe that's where the 1.86 came from. Either way it's still wrong because for video and film you shouldn't compare to full frame. The 5D is the only full frame sensor camera, so like I said it's the exception not the rule. Use Super 35 film as the basis.
 
some people says GH2 crop factor is 2x
some people says GH2 crop factor is 1.86x
Click to expand...

It's both when compared to full frame. 2x when compared to a 5D shooting stills and 1.8x when compared to a 5D shooting video. And, crop is slightly misleading, as the GH cams are the only large sensor cams that I'm aware of that don't crop the sensor, but use different areas of it to achieve a 16:9 image.
Already been pointed out, but a more accurate comparison should be to S35, where the FOV difference is much smaller.
 
@mike
Its 1.86.
Gh2 uses a bigger than 4/3 sensor. When gh2 goes from 4x3 to 16x9, gh2 doesnt crop but uses differnt part of the sensor...

Its been explained a dozen times before. Check gh2's official webpage.

Gh2 has a wider fov than the af100 (which is closer to 2x)
 
Per the OP's question, i only answered it.If hes ff or s35 i really dont care. Now if were gonna argue about technical nonsense, id rather leave.Now, if 1.86 is accurate, i dont know. I know gh2 is wider than a regular 4/3. Id rather not do any math. Ask barry. Hes the guy to answer this question
 
You just said it's 1.86 and then in your next post you say you don't know? I'm confused. Regardless, whether it's 2.0, 2.1, or 1.86 when compared to the 5D, it doesn't matter because we shouldn't be comparing it to the 5D for video. The 5D is the exception, not the rule. Compare to S35 16x9 film, which would make it a 1.4x crop if it's a normal 4/3 sensor, or even less than 1.4x if it's actually larger than a regular 4/3 sensor. I wasn't aware the GH2 has a slightly larger sensor than a regular 4/3 sensor. Would be nice for clarification on the size of the GH2 and AF100 sensors when shooting 16x9 video so we can get an accurate crop factor when compared to S35 16x9 film.
 
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At the end of the day, all that matters is knowing what a 10mm, 14mm, 28mm, 50mm etc will look like on any given sensor. If it helps some people to compare it to shooting FF, then fine, whatever works.
 
Here's a visual diagram that illustrates how the GH-2 sensor area is wider for 16:9 format shooting, compared to 4:3 format shooting. In 16:9 mode the GH-2 has a crop factor of 1.86 compared to a Full Frame 35mm Still Photo camera ( like the 5D MK2 ) which crops it's sensor when shooting 16:9 format.

Always keep in mind that the 35mm Full Frame Still Photo Camera format ( Canon 5D MK2 ) is a MUCH larger size than the 35mm Motion Picture Camera format.

The APS-C format size ( Canon T3i / 60D / 7D ) is almost the same as the Super 35mm Motion Picture Camera format, and thus the crop factor for the GH-2 becomes pretty meaningless in terms of 35mm Motion Picture formats.

GH-2 Sensor Diagram ( on the right side )
 
Taking into account the GH2 sensor diagram showed in previous post the GH2 frame will be 18.8mm x 10.6mm for 16:9 video.
So the diagonal will be: 18.8 x 18.8 + 10.6 x 10.6 = 465,8 SQRT = 21,58
The Full Frame 35mm still is 36 x 24mm, So the diagonal will be 36 x 36 + 24 x 24 = 1872 SQRT = 43,26
So the GH2 crop factor will be 43,26 / 21,58 = 2
 
I think the confusion is happening because aspect ratio is not being considered. A 35mm FF still camera has an aspect ratio of 3:2, HD video is 16:9, motion picture cameras support a wide variety of aspect ratios. You can compare diagonal dimensions and that will give you one ratio. If you standardize on an aspect ratio then different cameras will crop the image differently to achieve that aspect ratio. Then the comparison becomes the diagonals compared as cropped. For example, if you crop an academy 35mm frame (22mm x 16mm) to fit a 16:9 aspect ratio you get a 22mm x 12.4mm image. The GH2 has a 19mm x 10.7mm image (for video). If you crop the GH2 frame to match the 35mm academy frame you get an effective image size of 14.7mm x 10.7mm. Depending on which aspect ratio you are using, the ratio between image sizes will be very different.
 
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Apefos Adapter said:
Taking into account the GH2 sensor diagram showed in previous post the GH2 frame will be 18.8mm x 10.6mm for 16:9 video.
So the diagonal will be: 18.8 x 18.8 + 10.6 x 10.6 = 465,8 SQRT = 21,58
The Full Frame 35mm still is 36 x 24mm, So the diagonal will be 36 x 36 + 24 x 24 = 1872 SQRT = 43,26
So the GH2 crop factor will be 43,26 / 21,58 = 2
Click to expand...

Sigh .... not if the comparison you want to make is with the 5D shooting 16:9 video (which is often the context). TheDingo explains it clearly and correctly.
 
We calculated 1.86x versus full frame years ago with the GH1. So 1.86 versus ff and about 1.46 I'm comparison to aps-c I'm video.
 
would this be correct?
5D sensor: 36 x 20.25mm, so 36 x 36 + 20,25 x 20,25 = 1706 SQRT = 41,3 / 21,58 = 1,914 (crop factor between GH2 and 5D both for 16:9 video)
 
You're miscalculating how wide the actual 4/3 sensor is, which panasonic explains it's using for recording. Then, how tall the 5D actual 16:9 image is when recording. If I remember right the diagonal for 5D is about 32mm not the full 35/36. Gh2 should be about 18mm diagonal.

That's about 1.8x
 
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