GMPhotography wrote:
Given Sony is compressing there raws as no one else is doing are we just assuming that color space setting in camera is for JPEG only. I mean that's how it should be but who knows what Sony is thinking here or doing.
Sony wouldn't even have to be doing anything to the RAW other than leaving a tag that says it was shot with that setting set to sRGB and the the RAW converter is using that tag when it shouldn't be. I think we have to see if the posterization is a RAW converter related issue. I think it very well may be.
Fred Miranda wrote:
When the A7R came out there were a lot of discussion about sky posterization. From the RAW files I was able to test, the issue was always related to profile mismanagement. (assign/convert)
Unfortunately, it's not "only" mismanagement, it's also the type of profile conversion engine used, and what precision is used to do the conversion. Most systems (most notably ColorSync on OSX) often use a lower precision than needed in the reference space that is used as the midpoint in the conversion. It is often done like:
[original space] > [reference space] > [output space]
This means that if you convert TO a lower bit-precision, that same precision is used in the reference space. And if the reference space is larger than the output space, then 1 bit-step in the intermediate value might mean 2-3 valuesteps in the output: And here comes posterization.
The problem for Sony right now is that the original space (raw "space", even if there's no such thing really, raw space is a secondary inference, not a real defined space...) is large in blue. That gives a huge step in the XYZ D50 reference for each raw step. When that big step is converted to say sRGB, one step in the XYZ space might give a 3-bit-step delta in the output. One step suddenly becomes three....
That's why "16-bit" or even floats, used through all of the computations all the way up to the final conversion is so good. Another thing to note is that you have to apply the raw noise reduction AFTER the initial reference space conversion, not on the original raw data.
Basically it's the same thing as the megapixel thing I'm always on about. You want (lots of!) more MP in the original than your final output needs - preferably at least a 2:1 ratio! - to be able to do spatial transforms like distortion correction, rotation, scaling and so on "losslessly". Spatial transforms always have a safe MTF towards the 1/f point, i.e pixel-to-pixel contrast in the original to avoid creating new problems when moving stuff around.
I think so as well. Usually posterization is a color management issue with conversion to SRGB. What if Sony is leaving a tag on the raws as you said. This is a problem. I have yet to run into it but my in camera setting is set to Adobe RGB as my standard setting.
GMPhotography wrote:
Question for the morning. Folks that are seeing posterization in there files . What do you have your color space set for in camera. You have two choices SRGB and Adobe RGB. Reason I ask is if your SRGB I'm wondering if Sony is converting the raws in camera or its only going after the Jpegs in camera. I always set it to Abobe RGB and normally this is for in camera Jpegs but one wonders if Sony is tagging the raws SRGB and we don't know it. Theory only it's coming in SRGB the raws but when you import it's converting to your raw processing working color space and we simply do not know that. This would be bad as your shooting in a smaller color space than importing into a larger one and your import is adding color data to fill up the wider color space. Question is is Sony actually cooking the raws into the SRGB space when that is set. How can we figure that out?
This is just a thought. I have no proof of anything but just thinking out loud....Show more →
With normal raws, it should make no difference what the camera is set for as it's only during conversion of the raws later that the choice takes effect (part of the nature of shooting raw, just like WB can be chosen after the fact/ shooting). I also always set my cameras up for AdobeRGB as well for the back up jpegs though. That said, I have not tested this with Sony and their cooked raws so...
Agree with normal raws it should make no difference that in camera setting but if these Sony raws are cooked is why I thought of this.
Tariq you may know this as well. When I had my phase backs it was 16 bit raws but the IIQ file extension they used and I'm remembering that the raws where actually in a much bigger color space than Adobe RGB and one of the Phase One digital techs telling me to use Prophoto color space instead as it was just slightly smaller than the actual raw file coming in. In essence the raw was in a bigger color space than what we actually use. My fear here is Sony and we think we are shooting a large color space but a tag is in place and should not be.
GMPhotography wrote:
Agree with normal raws it should make no difference that in camera setting but if these Sony raws are cooked is why I thought of this.
Tariq you may know this as well. When I had my phase backs it was 16 bit raws but the IIQ file extension they used and I'm remembering that the raws where actually in a much bigger color space than Adobe RGB and one of the Phase One digital techs telling me to use Prophoto color space instead as it was just slightly smaller than the actual raw file coming in. In essence the raw was in a bigger color space than what we actually use. My fear here is Sony and we think we are shooting a large color space but a tag is in place and should not be. ...Show more →
I don't know specifically about Phase but it doesn't make sense to me in general given there is no real "raw" color space as I understand things. theSuede might no better though. The only thing I can think is that the phase guy was suggesting that using ProPhoto was better than AdobeRGB simply because it is a larger space (and more future proof).
theSuede wrote:
Unfortunately, it's not "only" mismanagement, it's also the type of profile conversion engine used, and what precision is used to do the conversion. Most systems (most notably ColorSync on OSX) often use a lower precision than needed in the reference space that is used as the midpoint in the conversion. It is often done like:
[original space] > [reference space] > [output space]
This means that if you convert TO a lower bit-precision, that same precision is used in the reference space. And if the reference space is larger than the output space, then 1 bit-step in the intermediate value might mean 2-3 valuesteps in the output: And here comes posterization. ...Show more →
In this example, the mismanagement you are referring to occurs only for display purposes on the Mac if I understand you correctly (as the actual file profile conversion occurs in the specific raw converter). I have not noticed this myself on my macs (possibly because the display space used with my wide gamut monitor is not that far off from the AdobeRGB working space I use?).
p.15 #10 · Uncompressed 14 bit for A7sii and A7rii
That one is really OT. I haven't slept in years past a couple hours. Terrible. Okay I'm heading back to my VC 15 and start working on that lens surgery and posting. My petal cuts went well , now cleanup.
p.15 #11 · Uncompressed 14 bit for A7sii and A7rii
GMPhotography wrote:
That one is really OT. I haven't slept in years past a couple hours. Terrible. Okay I'm heading back to my VC 15 and start working on that lens surgery and posting. My petal cuts went well , now cleanup.
Sorry to hear that. I'm usually the same. Sleep 2hrs, wide awake at 3/4am, finally get back to sleep right before it's time to actually get going in the morning.
p.15 #12 · Uncompressed 14 bit for A7sii and A7rii
GMPhotography wrote:
Question for the morning. Folks that are seeing posterization in there files . What do you have your color space set for in camera. You have two choices SRGB and Adobe RGB. Reason I ask is if your SRGB I'm wondering if Sony is converting the raws in camera or its only going after the Jpegs in camera.
No, there are no colour space conversions happening in camera.
GMPhotography wrote:
Question is is Sony actually cooking the raws into the SRGB space when that is set. How can we figure that out?
Apart from the fact that it would make absolutely no sense and completely go against the concept of storing mosaiced data... you could find out by shooting two images with different colour space settings and comparing the RAW files.
GMPhotography wrote:
Tariq you may know this as well. When I had my phase backs it was 16 bit raws but the IIQ file extension they used and I'm remembering that the raws where actually in a much bigger color space than Adobe RGB and one of the Phase One digital techs telling me to use Prophoto color space instead as it was just slightly smaller than the actual raw file coming in.
The RAW is in no colour space, it stores intensity information only. The interpretation of that intensity information may require a large working space in order to avoid clipping during conversion.
p.15 #13 · Uncompressed 14 bit for A7sii and A7rii
Matt not trying to question you but how do know if it is or is not being converted in camera with a SRGB tag. Is there a program or something to confirm that.
3rd part of your answer okay no color space just intensity of data but what if Sonys SRGB tag is sticking to the raws on import. I see it this way they are doing something no one does with there raws , why would this area be any diffrent. They obviously are doing weird stuff that makes little sense
p.15 #14 · Uncompressed 14 bit for A7sii and A7rii
I'm playing devils advocate here. I'm questioning what they are doing or not doing. As I said it's a thought given they are doing this compression algorithm to start with.
p.15 #15 · Uncompressed 14 bit for A7sii and A7rii
Color profile on a raw file is a non-sense yes. LightRoom display the raw into ProPhoto color space and convert datas only during exporting regarding your options.
Color profile option on camera may have an impact on the review on camera anyway.
p.15 #16 · Uncompressed 14 bit for A7sii and A7rii
You may have missed this. If Sony is tagging the raws(question mark) in camera with a SRGB color space than its coming into LR as a SRBG raw file. You import will change to whatever color space you have set in LR.
Basically I'm saying the raw is possibly already SRGB before even hitting LR. This would be really bad as its coming in a small color space and LR if set to Abobe RGB is trying to stretch the color space.
My cooking of the raws in camera scenerio. I doubt very highly this is happening but given Sonys raw compression which comes directly from video experience are they making a fatal mistake here. How can we tell that the raw is just intensity data or is it a SRGB .
We all know it should be that's really not the question it should be just intensity data and your raw converter makes into the color space you want. I always use Prophoto as that is the largest available to us. Are they screwing around with the raws is the question in regards to color space
p.15 #17 · Uncompressed 14 bit for A7sii and A7rii
I doubt LR even check for color profile in a raw file. And why the hell Sony would tag a raw into one of the smallest color profile ? They would better stop f...ing their amazing sensors outputs if so !
p.15 #18 · Uncompressed 14 bit for A7sii and A7rii
KiboOst wrote:
I doubt LR even check for color profile in a raw file. And why the hell Sony would tag a raw into one of the smallest color profile ? They would better stop f...ing their amazing sensors outputs if so !
That's exactly the question mark. They should not be using there raw compression either. But they are ,
