FAQ FAQ  Forum Search   Events   Register Register  Login Login

A7iii - Continuous, compressed etc

Author
lonewolf View Drop Down
Senior Member
Senior Member

Joined: 21 July 2014
Country: Australia
Location: Perth
Status: Offline
Posts: 1003
Post Options Post Options   Quote lonewolf Quote  Post ReplyReply Direct Link To This Post Topic: A7iii - Continuous, compressed etc
    Posted: 19 September 2020 at 15:23
So i've recently gotten an A7iii after years shooting other systems (awesome!)
After doing things the way i normally do, which is to expose for the highlights and then bring up the exposure/shadows in post.

Looking at some photos showed me a shedload of colour noise on black items that i recovered.

Upon double checking and re-reading my research it revealed to me 2 things
1) the old lossy compression vs uncompressed saga
2) That continous shooting drops down bit-level to 12bit.

From my shooting with Nikon i find that 12bit isnt an issue (especially at higher ISO's) so i suspect that it fully just comes down to the compression but certainly not ideal.
I pretty much shoot everything in at least mid FPS.

Anyone else noticed the noise issue - im sure everyone is like "just expose properly" but would be nice to preserve the highlight detail too.

May just have to put up with the double of file sizes and loss of buffer capacity
a7iii, 200-600, 28 F2, 85 F1.8 + lots of Nikon stuff
 



Back to Top
pegelli View Drop Down
Admin Group
Admin Group
Dyxum Administrator

Joined: 02 June 2007
Country: Belgium
Location: Schilde
Status: Offline
Posts: 29565
Post Options Post Options   Quote pegelli Quote  Post ReplyReply Direct Link To This Post Posted: 19 September 2020 at 15:33
I don't have an A7iii but a ii and a Rii.

I don't see any of this issue, even not when I have an underexposed shot. Shadow noise is hardly an issue for me unless I go over iso 3200 or 6400. But I realise that noise tolerance is a personal thing.

I use compressed raw and never shoot continuous, so if I were you I would test all combinations of compressed/uncompressed, 12 bit/14 bit to be sure you're drawing the right conclusion of what has the most effect on your shadow noise problem.
Mind the bandwidth of others, don't link pictures larger then 1024 wide or 960 pix high, see here
Back to Top
QuietOC View Drop Down
Senior Member
Senior Member

Joined: 28 February 2015
Country: United States
Location: Michigan
Status: Offline
Posts: 2917
Post Options Post Options   Quote QuietOC Quote  Post ReplyReply Direct Link To This Post Posted: 19 September 2020 at 15:42
The lossy compression doesn't increase noise. It just reduces color resolution where there is high dynamic range in a small spatial area.

Have you tried using the second gain? The base gain does show a lot more shadow noise.
Sony A7III NEX-5T HVL-F45RM LA-EA3 LA-EA4 MB-IV MC-11 EF-E II MD-NEX KR-NEX DA-NEX
Minolta Maxxum 600si
Pentax Q7 5-15 15-45/2.8 8.5/1.9 11.5/9 AF-P/Q
Back to Top
lonewolf View Drop Down
Senior Member
Senior Member

Joined: 21 July 2014
Country: Australia
Location: Perth
Status: Offline
Posts: 1003
Post Options Post Options   Quote lonewolf Quote  Post ReplyReply Direct Link To This Post Posted: 19 September 2020 at 16:23
This was a quick and dirty of compressed vs uncompressed - some more testing to be done
ISO100, 2.25EV exposure push and +100 shadows



And a real world example
a7iii, 200-600, 28 F2, 85 F1.8 + lots of Nikon stuff
Back to Top
addy landzaat View Drop Down
Senior Member
Senior Member

Joined: 22 April 2006
Country: Netherlands
Location: Netherlands
Status: Offline
Posts: 10713
Post Options Post Options   Quote addy landzaat Quote  Post ReplyReply Direct Link To This Post Posted: 19 September 2020 at 20:09
There is no Exif in the pictures.

i do not know how much "+100 shadows" is. Is it a setting of your RAW converter? Which is it? I do not know how many stops it is.

It looks ugly though.
Why not follow me on Instagram? @Addy_101
Back to Top
lonewolf View Drop Down
Senior Member
Senior Member

Joined: 21 July 2014
Country: Australia
Location: Perth
Status: Offline
Posts: 1003
Post Options Post Options   Quote lonewolf Quote  Post ReplyReply Direct Link To This Post Posted: 20 September 2020 at 02:11
the 2nd one is iso100, f1.8, 85mm, 1/8000th to combat the bright background (a bit over the top in this case)
Lightroom measures shadow/highlight recovery by score rather than stops
a7iii, 200-600, 28 F2, 85 F1.8 + lots of Nikon stuff
 



Back to Top
addy landzaat View Drop Down
Senior Member
Senior Member

Joined: 22 April 2006
Country: Netherlands
Location: Netherlands
Status: Offline
Posts: 10713
Post Options Post Options   Quote addy landzaat Quote  Post ReplyReply Direct Link To This Post Posted: 20 September 2020 at 11:07
I did a little Google search, +100 is the maximum setting based on the picture, quite extreme. As one site said: "The Shadow slider, pushed to the right or left, isn't destructive to a properly exposed image. However, if your histogram is weighted towards the left side, it's possible for the Shadow slider to modify a majority of the values in your image" - the last thing is what happened in your picture. You went beyond the possibilities of the picture you took.

I wonder how the original pictures look like. Did you underexpose by much? As you seem to be saying you exposed the second picture for the background it seems you did. There is about two stops in the highlights with most Sony sensors, you can expose in between the high and low lights.

Anyway, you stretched the picture past its limits it seems. Is this is the lossless compressed RAW? If not, use that.
Why not follow me on Instagram? @Addy_101
Back to Top
lonewolf View Drop Down
Senior Member
Senior Member

Joined: 21 July 2014
Country: Australia
Location: Perth
Status: Offline
Posts: 1003
Post Options Post Options   Quote lonewolf Quote  Post ReplyReply Direct Link To This Post Posted: 20 September 2020 at 11:18
Yes it was quite a stretch, but i often use +100 on Fuji and Nikon bodies and havent seen the issue (they all use lossless compression)
Was shot with highlight weighted metering

Also seems like it's not a problem with uncompressed raw - so its obviously what gets lost with compressed raw with the Sony algorithms.

Sony doesnt have a lossless compressed raw option...
a7iii, 200-600, 28 F2, 85 F1.8 + lots of Nikon stuff
Back to Top
addy landzaat View Drop Down
Senior Member
Senior Member

Joined: 22 April 2006
Country: Netherlands
Location: Netherlands
Status: Offline
Posts: 10713
Post Options Post Options   Quote addy landzaat Quote  Post ReplyReply Direct Link To This Post Posted: 20 September 2020 at 13:07
Sorry, my bad. I thought Sony introduced a lossless compressed RAW, but it was just uncompressed RAW.

Compressed files will fall apart quicker then uncompressed files. That might explains why your Fuji and Nikon do not show this. Or their Highlight metering is less aggressive then Sony's and the darks are less dark therefore.

Anyway, this Mark Galer Video about Sony Metering might be helpful.
Why not follow me on Instagram? @Addy_101
Back to Top
lonewolf View Drop Down
Senior Member
Senior Member

Joined: 21 July 2014
Country: Australia
Location: Perth
Status: Offline
Posts: 1003
Post Options Post Options   Quote lonewolf Quote  Post ReplyReply Direct Link To This Post Posted: 20 September 2020 at 15:15
Originally posted by addy landzaat addy landzaat wrote:

Sorry, my bad. I thought Sony introduced a lossless compressed RAW, but it was just uncompressed RAW.

Compressed files will fall apart quicker then uncompressed files. That might explains why your Fuji and Nikon do not show this. Or their Highlight metering is less aggressive then Sony's and the darks are less dark therefore.

Anyway, this Mark Galer Video about Sony Metering might be helpful.


Yep such a shame Sony doesnt offer lossless compression!
Will just deal with the file size/buffer issue and move on.

In my research also shows the A9 drops down to 12fps with uncompressed raw too
a7iii, 200-600, 28 F2, 85 F1.8 + lots of Nikon stuff
Back to Top
Dyxum main page >  Forum Home > Equipment forums > Camera Talk > E-mount full frame

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.063 seconds.

Monitor calibration strip

Dyxum.com - Home of the alpha system photographer

In memory of Cameron Hill - brettania

Feel free to contact us if needed.