Desperate about poor video quality of sony a6400

[Dylan94]

Hi guys! 

 

I am here to seek help for my videos! I have bought since a year or so a sonya6400 and I have been quite happy with my photos. I am not a professional and I have been saving up to buy new lenses.

I have been pretty sad honestly about the video quality I get out of my camera and I do not understand AT ALL the reason! At the beginning I was using a standard 1080p and it lacked details so I decided to move up to 4k and tried to use HLG3 recording but still the results are as bad as before! 
In these two clips you can see the comparison between my sonya6400 and the kitlens vs a sony a7 IV with a good lens(not sure which was it). The results are  like too different! I do not understand how come!

Some info about the video that I know are:

file size: 27.9GB after 1h ca. of continuous recording

ISO: 12.800 ; F.8 ;  SS. 1/60 ; XAVC S 4K ;  24p 60M ; HLG3 (-7detail on camera)with adj in post (I also downscaled the video to 1080p during the export to hopefully have a nicer quality but nope)

The second video with a sony a7 IV was like 60+ GB so that means it was shot(I think) at 24p 100M

 

Is it only a problem of lens sharpness? I think the person who did the second video has a very expensive lens 1k-2k. 

 

 

SONY a6400

SONY a7 IV

 

 

Thank you already for your time!

 

p.s. I just noticed that when I uploaded the video to youtube of the sony a7 IV there is the icon "4K" next to the video while on all my other videos it never appears even if it was record and exported in 4k

p.s. 2 My SD-Card is a Lexar professional 128GB 95 MB/S 633x. Could that also be the problem?

[porina]

In a quick look I think there are two problems.

 

ISO12800 is very high, so a ton of noise reduction is needed resulting in a mushy look. The fix is "more light". In this case you don't control the environment, so the alternative is faster lens - if you can still maintain sufficient depth of field. You say you're using f/8, opening it up could have helped.

 

Also your focus seems to be off. The plants at the front look sharper than the performers. The highlights show a circular pattern where they are. Given this was static I would have manually done focus and leave it. AF can pick random things. Beware if environment temperature changes the focus can shift as the lens thermally shrinks/expands.

[Dylan94]

thank you very much!

So for the iso yes I know it's very high but I thought about ss 1/60 and f.8 and I used the iso to compensate! 

My thought process was " f.8 should get everything in focus, even if I don't get the right focus it should be good enough"  I tried to MF the shot, and from what I remember it was set on the piano at f8 I thought it should have got the performer(me) in focus. My problem usually is that I cannot control focus because I am usually on stage.

 

Do you think that with these adjustments the result would be on par? Should I do other stuff? The image is also only slightly cropped in. From what I see on youtube the other video on youtube it gives me the option of 4k 50p even though I did the same exact export from Premiere pro. Why is that?

[porina]

23 minutes ago, Dylan94 said:

My thought process was " f.8 should get everything in focus, even if I don't get the right focus it should be good enough"  I tried to MF the shot, and from what I remember it was set on the piano at f8 I thought it should have got the performer(me) in focus. My problem usually is that I cannot control focus because I am usually on stage.

The piano doesn't look in focus. So either you made a mistake or something changed after you set it. I don't know what setting you have on that camera, but I would use maximum display zoom on a high contrast part where I want to focus, and optimise that.

 

23 minutes ago, Dylan94 said:

Do you think that with these adjustments the result would be on par? Should I do other stuff?

Getting the focus right is a basic start. I'd suggest getting more practice on manual focus especially in lower light. Try with the lens wide open as that'll make focus errors bigger. You can get a feel for what the image quality might be like that way before considering other options.

 

23 minutes ago, Dylan94 said:

The image is also only slightly cropped in. From what I see on youtube the other video on youtube it gives me the option of 4k 50p even though I did the same exact export from Premiere pro. Why is that?

Cropping also wouldn't help with the image quality, since you're effectively magnifying what's there. No idea on Youtube things.

[Dylan94]

ah ok! thank you a lot for your feedback! I will be trying out the things you said! many thanks !