GH4 Crop Factor Confusing....

[iGamer4tv]

What a do, what's good, you know what it is, question time.

First post here,

I do not quite understand why some recording formats in true 4k and normal 4k give me different crop factors? Like some 4k settings make the video less zoomed out, and some recording formats like MOV tend to zoom in the shot a little more? I thought it was supposed to stay at a 2.3 crop factor or something. I honestly have no idea lol just need a good camera. 

What can I do to take it the least zoomed out of my prime lens, and the best 4k 29FPS quality?

Lens is Sigma M43 30mm/f2.8

Thanks

[webrunner5]

I guess you are talking the difference between  4096x2160 and 3840x2160?? They are different crop factors. One is using in essence full frame, and the higher one using a cropped section of the sensor. I am pretty sure the crop factor you are talking about IS different for each.

"The full sensor is 4608 px wide, so the math works out to a 1.125 crop factor for Cinema 4K's 4096 px width (in m4/3 terms), and 2.25 crop factor relative to FF. Your 7mm WA lens suddenly becomes almost 8mm - a noticeable change.

For UHD at 3840 px wide, the factor is 1.2 x m4/3 FL, or 2.4 relative to FF. 7mm is now 8.4/16.8mm; and your 25mm a 30/60mm.

FHD 1080 will continue to use the full sensor width and preserve the nominal FL."

Pete from DPR.

So yes there is a change in the Crop Factors if this is your question? Maybe I am not understanding your question, please inform me and others if we don't answer your question. There is no better way to learn than to ask for advice, and there are a lot of very capable people on here that will help. Welcome aboard.

[iGamer4tv]

Thanks for the reply. You do understand my question, its just I do not understand most your answer, though I do get it. The different resolutions with the lens m4/3  using 4k is not full frame? So, 1080 uses the full sensor, can I do it with 4k settings?

Thanks

[jonpais]

39 minutes ago, iGamer4tv said:

Thanks for the reply. You do understand my question, its just I do not understand most your answer, though I do get it. The different resolutions with the lens m4/3  using 4k is not full frame? So, 1080 uses the full sensor, can I do it with 4k settings?

Thanks

There will always be a crop in 4K, so the answer is no.

[iGamer4tv]

57 minutes ago, jonpais said:

There will always be a crop in 4K, so the answer is no.

I just want to understand why, is it my camera, the lens, just the format itself? So, the only way to get the most of 4k is to just get a wider lens to get more of the picture?

[jonpais]

46 minutes ago, iGamer4tv said:

I just want to understand why, is it my camera, the lens, just the format itself? So, the only way to get the most of 4k is to just get a wider lens to get more of the picture?

I'm assuming you're on a budget, so if you want to go wide, I'd suggest getting a Samyang/Rokinon 12mm f2 lens. They can be had for less than $200.00 used. Another option is to get a cheap Chinese focal reducer and a Tokina 11-16mm f/2.8.

[iGamer4tv]

12 minutes ago, jonpais said:

I'm assuming you're on a budget, so if you want to go wide, I'd suggest getting a Samyang/Rokinon 12mm f2 lens. They can be had for less than $200.00 used. Another option is to get a cheap Chinese focal reducer and a Tokina 11-16mm f/2.8.

Yeah somewhat of a budget. Does the focal reducer go on top my lens? Say I just get that and add it on to my lens now, would that work?

[jonpais]

13 minutes ago, iGamer4tv said:

Yeah somewhat of a budget. Does the focal reducer go on top my lens? Say I just get that and add it on to my lens now, would that work?

Mitakon adapter. It goes between the lens and the camera. It won't work with u4/3 lenses. It will run around $150.00 new, but you might find a used one on eBay for less. Hope that helps.

[iGamer4tv]

5 minutes ago, jonpais said:

Mitakon adapter. It goes between the lens and the camera. It won't work with u4/3 lenses. It will run around $150.00 new, but you might find a used one on eBay for less. Hope that helps.

Thanks, ill look into this. If I just have to buy this I can keep it and use that or just the lens alone some days. 

[jonpais]

1 minute ago, iGamer4tv said:

Thanks, ill look into this. If I just have to buy this I can keep it and use that or just the lens alone some days. 

Actually, the Tokina must be used with an adapter, it's an APS-C mount lens. Another possibility is to look into a used Panasonic 20mm f/1.7 pancake. It's not too expensive and it will give a wider field of view than the Sigma. Many people love the 20mm.

[Kisaha]

@iGamer4tv 

"I just want to understand why, is it my camera, the lens, just the format itself? So, the only way to get the most of 4k is to just get a wider lens to get more of the picture?"

The crop factor doesn't change, you will always will have the crop factors mentioned above, whatever lens you will choose.

Well, better read here https://www.bhphotovideo.com/explora/video/tips-and-solutions/how-emulate-super-35mm-4k-video-panasonic-gh4 

I believe the only camera with no crop factor at all in every mode (including slow motion) is Samsung NX1. It is something to do with the processing power cameras has, and if they are able to do a full read out of the sensor or not.

The x2.2 and x2.4 form factor mentioned above are relative to the number your native m4/3 lenses are, look at the examples above and put your lenses mm to understand what focal lengths you get if you shoot 4K and what not.

Par example, for Sony a6300/a6500 

4K 24P/25P crop factor 1.5x (24MP full sensor readout, this has only the APS-C normal sensor crop factor, like m4/3 is x2, so it has a full sensor readout)

4K 30P crop factor 1.9x (13MP crop area full readout) that means a lens 50mm X 1.9 = 95mm

HD 120P crop factor 1.9x (13MP crop area pixel binning readout)

 

 

[webrunner5]

Now the new GH5  uses the full sensor so no longer a further crop like the GH4 in 4k, due to faster readout and chip design. But since it is a m4/3 camera it still will have a 2.0 crop factor being that it uses a m4/3 sensor. So the answer to your last question is sensor, not lens, the format itself, being that it uses that small of a sensor.

So there is no free lunch for lesser cameras LoL.