141 replies to this topic

[A Y]

The AdobeRGB version looks more contrasty to me, but you can also use a histogram to see the actual differences.

 

 

In case you're wondering, I'm using a browser plug-in written by a friend to show the histogram.  It works on almost every website except for Facebook, I think. Get it here for Chrome: https://chrome.googl...nmbmogdigoedhaj

[jgharding]

Good idea. I feel the difference is too subtle to be the difference between sRGB and Adobe1998 though, if you look at the kind of difference it should make.
 
My testing wasn't that consistent (it was five minutes at my desk between edits) so I think you can attribute the difference to that, realistically. It's probably just Rec709 space all round.
 
One chart here shows it's very subtle though, maybe it would explain the difference in the reds? Still, for my purposes I've concluded it's not worth worrying about, so I'll leave it on sRGB!
 
http://www.fxguide.c...macity-all.jpg]

[richg101]

on the subject of DRO. it appears to work best at iso200 from some experimentation I have done.


assuming you are exposing to avoid clipping of the sky, the shadow noise on darker areas boosted by DRO seems to be more prominent at iso100 than the shadow noise caused by DRO when iso is set to 200 with the lens aperture adjusted to match exposure of the sky.

This makes me think that base ISO of nex5n is actually 200 (as it was with the original nex-5 and nex-3), but is having some type of post exposure compensation to allow for the option of iso100. The processing is naturally going to cause some type of image degradation. This is likely the case with the rx100 too.

Maybe some one can look into this. If true it might be worth avoiding iso100 and starting at iso200 to avoid banding and other nasties. It is known that this is a main cause of banding/colour issues with the Canon 1DC when used at ISO lower than the actual Base iso of the sensor. Being that the previous nex models were base iso of 200 it seems funny sony would downgrade on the newer model.. rather than just applying some processing to offer a faux lower iso of 100.

Thoughts??

[Bruno]

Haven't tested it myself, most people seem to agree it's 125 though, also that's what's mentioned in the manual.
Some people claim that the highest DR at 200 ISO only happen when shooting JPGs with noise reduction on, which would make the improvement a post effect kind of thing, and not a real improvement, was this the case with your tests?

[richg101]

I have NR set to minimum and am talking in movie mode terms.

 

 

I am just adjusting my aperture to compensate for the difference in ISO.  It is just a lot less grainy in the shadows/darker areas (the areas boosted by DRO) when set to iso200.  Iso100 is significantly more grainy than iso200 in the DRO boosted areas.    

[mojo43]

Interesting!

 

I didn't realize that you can set NR in video mode. Where is that setting?

[richg101]

Interesting!

 

I didn't realize that you can set NR in video mode. Where is that setting?

 

Menu, settings, high ISO NR, Low.  I'm unsure what is determined as 'high iso' but it seems to affect the noise levels at all iso's

[mojo43]

I saw that, but I can't seem to set it when I am in video mode. I assume it's because I am not shooting in jpg. I would assume that the NR doesn't happen in video mode based on that, but I could be wrong. I would have to do some tests. Did you notice that it was doign NR in movie mode?

[Bruno]

I am just adjusting my aperture to compensate for the difference in ISO.  It is just a lot less grainy in the shadows/darker areas (the areas boosted by DRO) when set to iso200.  Iso100 is significantly more grainy than iso200 in the DRO boosted areas.    

 

Did you try doing the same test with DRO off? Is it still noisier at 100 ISO?

 

Btw, 100 ISO (and 80 ISO) is being pushed in post, 125 ISO should be the base one, and therefore offer cleaner results, have you tried that one instead?

[richg101]

Did you try doing the same test with DRO off? Is it still noisier at 100 ISO?

 

Btw, 100 ISO (and 80 ISO) is being pushed in post, 125 ISO should be the base one, and therefore offer cleaner results, have you tried that one instead?

 

without dro there doesnt seem to be a difference in noise between 100 and 200.  it's only when you go to iso100 with dro on that noise seems more prominent than at iso200.  PS.  this is on the nex5n, not rx100.  but since they share so many similarities with processing, etc I imagine these results will be similar on the rx100

[Bruno]

They have different sensors though, so it's very possible that their base ISOs are different. In the RX100 ISOs 80 and 100 are not proper ISOs, they're even marked differently. It's definitely worth testing though.

[Bruno]

Here's an ISO test.

These are all the ISO modes available during video mode.

125 is the cleanest, it's been mentioned in a few places that it's this camera's base ISO and it does look that way.

 

The only surprise here is that 400 ISO is actually less noisy than 200 ISO.

 

But overall, unless you push it really hard, the noise is barely visible before 3200 ISO.

 

[jgharding]

I'd say 400 is native probably. The fact that it has so little blue-channel noise (the biggest problem with current Sony sensors in my experience) is great to know, cheers for this test!

[richg101]

I'd say 400 is native probably. The fact that it has so little blue-channel noise (the biggest problem with current Sony sensors in my experience) is great to know, cheers for this test!

 

I agree.  400 seems the best noise vs gain ratio.

[jgharding]

In that sense you could treat the RX100 like 400ISO Super 16 film, leave the ISO fixed for the most part and light to the sensitivity

 

The sensor is about that size!

[Bruno]

Here's a comparison between 125 and 400 ISO.

I pushed the 125 version one stop further than the 400 one, so they're equally bright when desaturated.

It's definitely a different noise structure, but I seriously don't know what to make of it.

125 does seem cleaner, and keep in mind that it's been pushed further than the 400 ISO side.

 

Looking at how good the 400 ISO version looks though, I wouldn't be surprised if it is indeed the camera's base ISO, but it does seem a bit high of an ISO for them to go with, on the other hand it could explain why this little sensor can do so well in low light. Also, if 400 ISO is in fact its base ISO, then they're doing a great job when pushing it to 125, much better than when pushing it to 200, which is somehow odd.

 

This article (and most others I found) also claims that the base ISO is 125.

 

http://www.imaging-r...sony-rx100A.HTM

 

[jgharding]

Red and blue noise below 400, red noise only at 400, and red blue and green noise above 400. What a puzzler!

[richg101]

these tests have prompted me to do some lens cap tests of the nex5n, which seems to exhibit the same varied noise colour depending on iso setting..  I'm uploading now

[richg101]

how do I embed a video?

[richg101]

Nex5n iso test and dro test

 

 

password is: iso