Difference between screen grab from UHD video and jpg

[Storyline]

As the title suggests i wonder what is the difference between taking a screen grab or frame export from 4K footage compared to a still image jpeg ? I realise I can try this but just wondered what more experienced users think.
Was a bit disappointed today when I discovered I had no still images on my SD card as yesterday I hit the photo button on the controller several times whilst filming as I thought I had read you could do it !

 

[sonof40]

My understanding is that you have to stop video before using photo. Wish it weren't so.

 

[Kilrah]

It's correct. A real photo will always be better since the JPG compression is much less destructive than video-oriented codecs.
On the MA a grab is already great, on the MP the compression is much more noticeable but at reasonable output sized it still works.

This was quite successful despite being an MP grab.


Last fall days - Explored, thanks!

 

[Storyline]

.....
This was quite successful despite being an MP grab.
.....

That's an understatement - I think it was very successful !

 

[Swirleigh]

MA? MP?

 

[53-63-6f-74-74]

Screenshots will probably work out fine for small pics and such, but to get the most out of your camera you should be shooting stills in raw format and post processing (or JPG + RAW both). You have to pull out as much as you can from the MP (Mavic Pro for Swirleigh). The difference between a screenshot vs. a processed photo will quite noticeable.

 

[gnirtS]

As well as the above its a reduced resolution. 4k is about 8mpixel. The camera image is going to be 12mpixel.
As well as lacking editing ability, dynamic range, will contain noise reduction and compression artefacts, motion blur if the correct ND filter is used.