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A7RII first impressions and LOTS of RAW files

tashley

Subscriber Member
Tim, Sony has been implementing a conversion switch tactic to squeeze the best DR out at low ISO and high ISO and it has to do with video too I guess. The switch is not exactly at ISO 800. Here is a couple of articles Jim Kasson just made:

Sony a7RII engineering dynamic range | The Last Word
a7RII read noise with EFCS on and off, plus silent, continuous | The Last Word

Edit: In a way, we have at least 2 base ISOs (or 3) :D
Fascinating! Thank you! So as I read that, base ISO is either 50 or 100 (both have the same DR) and then just under 800, presumably in order to make the video work as it needs to. Maybe I need to update my assumptions!
 

Leigh

New member
...the A7RII has a base ISO of 800 and the D810 has a base ISO of 64.
That's backwards.

The lowest ISO is determined by the number of samples that are averaged together.
It can be whatever number the designers want it to be.

The sensor "base" sensitivity is given by its highest ISO rating.
That defines what information can be captured in a single sample.

- Leigh
 

vjbelle

Well-known member
Without ado and after about 100 frames, therefore highly provisional...
Tim,

Your raw files are very informative especially image #84 shot with the Sony 55 at f5.6. That image shows the weakness/strength of that lens and camera combination. I would probably look elsewhere but that's just me.

Victor
 

tashley

Subscriber Member
Tim,

Your raw files are very informative especially image #84 shot with the Sony 55 at f5.6. That image shows the weakness/strength of that lens and camera combination. I would probably look elsewhere but that's just me.

Victor
Hi Victor,

Just out of curiosity, what are you seeing there that makes you keen to look elsewhere? Per lens alone, I prefer the Sony to for example the Sigma Art, because it is sharp all over the frame right from wide open.
 

vjbelle

Well-known member
Tim..... I'm being very picky but I have the right to be if I'm using my money...... as an example I don't even own an Otus any more - and I had three copies.:eek: I see some smearing on the right hand side at maybe the 2/3 point..... but throughout the right side as compared to the left. At f5.6 I expect the lens to be close to perfect when photographing planar subjects. I don't believe the issue has anything to do with curvature. Again..... this is just me. Oddly I've been very critical of my Leica Summicron 50mm which has horrendous focus shift issues and is not as sharp as the Sony 55mm but it is very, very even from left to right.... not even a hint of decentering. I find that a real accomplishment since I can get around the focus shifting and can easily post process for sharpness issues. However, that's not where I would look for an alternative....

Again..... thanks so much for taking the time to post.

Victor
 

tashley

Subscriber Member
Tim..... I'm being very picky but I have the right to be if I'm using my money...... as an example I don't even own an Otus any more - and I had three copies.:eek: I see some smearing on the right hand side at maybe the 2/3 point..... but throughout the right side as compared to the left. At f5.6 I expect the lens to be close to perfect when photographing planar subjects. I don't believe the issue has anything to do with curvature. Again..... this is just me. Oddly I've been very critical of my Leica Summicron 50mm which has horrendous focus shift issues and is not as sharp as the Sony 55mm but it is very, very even from left to right.... not even a hint of decentering. I find that a real accomplishment since I can get around the focus shifting and can easily post process for sharpness issues. However, that's not where I would look for an alternative....

Again..... thanks so much for taking the time to post.

Victor
Crikey, you are eagle eyed - I though I was very particular about the symmetry of my lenses but I considered this a good copy! I suggest that unless you have smelling salts to hand you don't look at this, which is from my FE 16-35 F4. I returned it for service under warranty today... :)
 

tashley

Subscriber Member
Holy crap! I sold my copy, but yours is far worse. :thumbdown:

Any ideas for a super-wide (<25mm)? Other than using my D810 with the 14-24mm?

Joe
I'm sticking with the 16-35 Joe - getting it fixed. It is so much better than I expected at 16/24/28 and I hear such raves about it from people who have a good one that I am going to try to make the best of it. Actually apart from at that 35mm setting, it really is good, even on the 7rII
 

Quentin_Bargate

Well-known member
I don't think the A7RII is an ISO 800 camera. Its good at ISO 800, and indeed higher, but better - far better, at lower ISO.

In fact I have never entirely bought in to the obsession regarding high ISO performance of any camera. Useful, but not critical for my purposes.
 

tashley

Subscriber Member
I don't think the A7RII is an ISO 800 camera. Its good at ISO 800, and indeed higher, but better - far better, at lower ISO.

In fact I have never entirely bought in to the obsession regarding high ISO performance of any camera. Useful, but not critical for my purposes.
I'm with you on that Quentin - I very very rarely shoot much above the 80-200 ISO range but it's nice to be able to. I think what the above thread seems to have provisionally concluded is that there's no such thing as a base ISO for the sensor though - it seems to have two or three, depending on how the signal is processed thereafter. I think....:confused:
 

Quentin_Bargate

Well-known member
I'm with you on that Quentin - I very very rarely shoot much above the 80-200 ISO range but it's nice to be able to. I think what the above thread seems to have provisionally concluded is that there's no such thing as a base ISO for the sensor though - it seems to have two or three, depending on how the signal is processed thereafter. I think....:confused:
BTW, Tim, sorry about your 16-35mm. Terrible! Mine is not perfect, but a *lot* better than that - pretty good in fact. - how does such a faulty lens pass Zeiss quality control?
 

vjbelle

Well-known member
BTW, Tim, sorry about your 16-35mm. Terrible! Mine is not perfect, but a *lot* better than that - pretty good in fact. - how does such a faulty lens pass Zeiss quality control?
A very good question, Quentin. My thinking is that Sony sets the bar and Zeiss complies. I would sure like to have a 'real buddy' at Zeiss who would look out for 'really' good copies - just for me! That's a real dream..... but I can dream can't I?

Victor
 

algrove

Well-known member
Holy crap! I sold my copy, but yours is far worse. :thumbdown:

Any ideas for a super-wide (<25mm)? Other than using my D810 with the 14-24mm?

Joe
Maybe if you have a super wide M lens laying around, it might be worth a serious try.
 

Uaiomex

Member
I think that for the prices these kind of lenses command these days, manufacturers should exercise much tighter controls enough to satisfy the pickiest. Lens return for lack of IQ became everyday practice. A royal pita!

Or is it that we are asking too much these miniature sensors?
Eduardo



A very good question, Quentin. My thinking is that Sony sets the bar and Zeiss complies. I would sure like to have a 'real buddy' at Zeiss who would look out for 'really' good copies - just for me! That's a real dream..... but I can dream can't I?

Victor
 

vjbelle

Well-known member
I think that for the prices these kind of lenses command these days, manufacturers should exercise much tighter controls enough to satisfy the pickiest. Lens return for lack of IQ became everyday practice. A royal pita!

Or is it that we are asking too much these miniature sensors?
Eduardo
Its really a FF 35mm sensor - fairly decent size!! AND...... no we are not asking too much for these prices..... a real shame at this stage of the game.

Victor
 

Uaiomex

Member
I am 62. I think I'm entitled to call them miniature.:ROTFL:
Best regards Victor
Eduardo


Its really a FF 35mm sensor - fairly decent size!! AND...... no we are not asking too much for these prices..... a real shame at this stage of the game.

Victor
 

tashley

Subscriber Member
New stuff on ISO and DR: check out the links from this piece at SAR... it relates to a Chinese rental agency's lab tests and seems to show that the A7RII has better DR at higher ISO than the D810 but that the D810 has the best DR of both systems provided it is shot at low ISO. This might indeed imply that the 'native' ISO of the Sony is higher...???


'with the author conceding a “surprising” advantage for a sony camera over the d810 in terms of higher iso dynamic range performance. But also noting that in the low iso performance area so key to landscape photographers, d810 is still king.
Of course the main issue is the long exposure color noise in the shadows which starts to appear at shutter speeds greater than 1 second, really become a problem beyond 10 seconds, and is like an unwelcome dose of LSD beyond 30 seconds. The author demonstrates this by comparing pictures which have been adjusted +ev 5 for exposure and +100 for shadows in the shadow areas with d810, 5dsr, (and later on d800e, a7m2, and canon 6d). This actually could be a significant issue for landscape lovers '
 
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