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A7r, A7r2 - and why I'm keeping both ...

k-hawinkler

Well-known member
Evening Light



A7r2 + Leica WATE 16-18-21/4

Sometimes the light feels just right. The A7r2 + WATE indeed is a joy to use! :D
 

k-hawinkler

Well-known member
This paper http://www.dpreview.com/reviews/sony-alpha-7r-ii/8 seems interesting, quote:

"Shooting ISO Invariant using S-Log 2

On most cameras it's difficult to take advantage of their ISO Invariant nature because the camera's meter considers you to be hugely under-exposing and, even if your camera will present a preview that isn't related to exposure, the files you shoot are likely to appear almost totally black, making it very difficult to assess exposure.

Sony's S-Log 2 gamma curve: primarily designed for movie shooting, it ends up doubling as a handy way of making it easier to make use of the sensor's capabilities. The ways it does this are two-fold: firstly, because it offers an incredibly flat tone curve, the dark tones in the Raw file that you might want to make use of are pulled up and presented reasonably brightly.

Secondly, though, is the knock-on effect of this tone curve. Because ISO ratings are based on mid tones in JPEGs and the flat tone curve pulls its mid tones from a long way down the Raw file, the S-Log2 mode is considered to be a higher ISO than the normal tone curve. As a result, the lowest available ISO in S-Log2 mode is 800: not because the lower settings are being locked off but because an ISO 800 exposure is enough for a middle-grey object to be represented as a middle grey in the S-Log 2 JPEGs.

Looked at from a Raw perspective and what's happening is the camera is trying to use ISO 800 exposures but with much lower amplification than in standard mode, meaning highlights aren't being amplified out of the file. (If shot with the same exposure values, the ISO 800 Raw files from S-Log2 shooting appear to be somewhere between the ISO 125 and ISO 160 results in standard mode).

As a result, shooting in SLog-2 mode not only provides a more usable preview and output JPEG, it also essentially causes the camera to reduce exposure by 2.5EV to protect highlights.
"

So, I gave that line of thought a try, set ISO to 800 and took two shots, one with Picture Profile Off and one with PP7.

First the OOC JPGs, reduced in size only, no further processing.

OOC JPG, PP Off


OOC JPG, PP7


Indeed, when taking the shots, the images appear similarly in the EVF.


Next, images derived from the raw files with Default processing in C1.

Derived from .ARW file, PP Off, Default Adjustments


Derived from .ARW file, PP7, Default Adjustments


Here the PP7 derived image avoids the extremes of the highs and lows of the PP Off version.


And finally the images derived from the raw files with zero adjustments.

Derived from .ARW file, PP Off, 0 Adjustments


Derived from .ARW file, PP7, 0 Adjustments


As anticipated, for PP7 the camera reduced exposure by 2.5EV to protect highlights.

My take: I am going to try this approach with scenes of excessive DR, easily encountered in the "Land of Enchantment". :grin:
 

k-hawinkler

Well-known member
Now let's put the S-Log2 Picture Profile to use in an actual landscape shot.
This is the in size reduced OOC JPG. It's similar in appearance to LiveView in the EVF or on the LCD.




This is the image derived with C1 from the .ARW file and pretty close to what my eyes saw on a beautiful fall day here in the "Land of Enchantment"! :thumbs: :bugeyes:



A7r2 + WATE @ 21 mm in APS-C mode, so a FoV corresponding to 31.5 mm in 135 film and covered by 18 MP.
 
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Knorp

Well-known member
Many thanks Bart. You need to use C1.
Then this approach becomes almost effortless! :D
CS6 gives a totally flat image or mostly black. :loco:
Although crippled (no OpenCL) after I killed my cat, thank you El Capitan, C1 is still my preferred tool.
 
V

Vivek

Guest
What is the difference between this PP7 and the DRO settings? TIA.
 

k-hawinkler

Well-known member
What is the difference between this PP7 and the DRO settings? TIA.
Thanks Vivek. Great question.

Although with DRO you try to modify the hi and lo exposure areas, you do not underexpose the entire image by 2.5 stops to protect the hi areas. This method indeed does IMHO.

So, I would use this approach primarily for scenes in which the DR range exceeds the abilities of the camera in order to protect highlights. Although this method forces the camera to use ISO 800 the resulting noise level seems more typical for ISO 125 or 160 as explained in the quote from the dpreview staff.
 

k-hawinkler

Well-known member
After turning the silent mode off in my A7s, I could access the PP settings ( http://helpguide.sony.net/ilc/1420/v1/en/contents/TP0000435736.html?search=picture profile ).

Whoa! This is a whole different ball game! There are way too many parameters that can be selected to taste.

Q for K-H: Why did you go for PP7 when PP2 is recommended for stills?

Thanks Vivek. Very simple answer. I saw this method used for video and wanted to know what it does for stills. I am at the beginning of my learning curve and will now explore the other options. Let's continue to compare notes.
 
V

Vivek

Guest
Thanks Vivek. Very simple answer. I saw this method used for video and wanted to know what it does for stills. I am at the beginning of my learning curve and will now explore the other options. Let's continue to compare notes.
Will do. :)

[OT: I think this will take my UV captures to a totally new level (already with a hacked A7, it is still better than ever).
Now to fund a set of A7rII cams... :loco:]
 

k-hawinkler

Well-known member
Being totally new to Picture Profiles and Color Grading I don't think I got it quite right in post #43.
From what I understand now one takes a jpg image with the Picture Profile baked in and then Color Grades that jpg to create a Cinematic Effect.
Well, let me try again with a more fitting example, shot again with A7r2 and WATE and PP7. :grin:


OOC JPG



After Color Grading with C1.



Now the same process with the Lights switched off.


I don't think I could create the last two images above with using Creative Style. Picture Profile PP7 has definitely had an impact.
 
V

Vivek

Guest
Being totally new to Picture Profiles and Color Grading I don't think I got it quite right in post #43.
From what I understand now one takes a jpg image with the Picture Profile baked in and then Color Grades that jpg to create a Cinematic Effect.
K-H, No need for jpg. You can use your RAW with all the camera settings and convert it to tiff using Sony IDC (no need for C1 either). After that, you can use the images as such or further tweak them. I wish I could have provided some samples but I have to look for a less sharp lens (than the 35/2.5 Summarit M) to do that without severe color moire.

BTW, this (in camera profile settings which are more sophisticated than those of any other camera makers, AFAIK) is not unlike the use of a Nikon cam and NX2 to process the files.
 

Knorp

Well-known member
Hi there K-H,

I'm puzzled now: in what way you think now that you didn't get it quite right ?

Being totally new to Picture Profiles and Color Grading I don't think I got it quite right in post #43.
From what I understand now one takes a jpg image with the Picture Profile baked in and then Color Grades that jpg to create a Cinematic Effect.
Well, let me try again with a more fitting example, shot again with A7r2 and WATE and PP7. :grin:
This is the image derived with C1 from the .ARW file and pretty close to what my eyes saw on a beautiful fall day here in the "Land of Enchantment"! :thumbs: :bugeyes:
TIA

PS Still have to go out to try PP7 ... :eek:
 

k-hawinkler

Well-known member
K-H, No need for jpg. You can use your RAW with all the camera settings and convert it to tiff using Sony IDC (no need for C1 either). After that, you can use the images as such or further tweak them. I wish I could have provided some samples but I have to look for a less sharp lens (than the 35/2.5 Summarit M) to do that without severe color moire.

BTW, this (in camera profile settings which are more sophisticated than those of any other camera makers, AFAIK) is not unlike the use of a Nikon cam and NX2 to process the files.

Thanks Vivek for the tip. IDC is broken on El Capitan, so can't try that out right now. :banghead:
 
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