Pentax, please improve the JPEG engine

**Rondec** · 01-11-2014, 03:45 PM

I don't really worry about jpeg engine. Photos worth keeping are worth tweaking at least a little bit and I am better at doing that than the camera (cause I'm smarter, I guess). I know there are arguments about RAW versus jpeg all the time, but I am a RAW shooter all of the way.

Steve.Ledger · 01-11-2014, 05:46 PM

First of all, well underexposed. Look at the histogram, it's all to the left.
Get your exposure correct and the red plus detail will be much better.
Also check that NR is 'off'. NR will often muddy the waters.
I'd also change the parameters of the colour styles to suit your taste.

However, all is not lost - I dropped your JPG into FASTSTONE, corrected the exposure, lowered the blue channel and added some contrast.
The detail seems to be there and the colour looks fine to me (on my IPS monitors).
What do you think?

6BQ5 · 01-11-2014, 09:51 PM

My K-30 has a hard time with reds too. I don't know why. Any other shade and color is fine though. I cringe when I go out with my kids on a hike and they choose to wear red shirts! It's going to be a tough evening with Aperture then!

geru2000 · 01-12-2014, 05:32 PM

Originally posted by 6BQ5

My K-30 has a hard time with reds too. I don't know why. Any other shade and color is fine though. I cringe when I go out with my kids on a hike and they choose to wear red shirts! It's going to be a tough evening with Aperture then!

I also own the K30 but experience no problems with shooting reds. In fact I was playing with the camera this afternoon and my subject was a red solo cup (seriously). Shot in bright and sharpening set to -3 or 4 all noise reduction and sharpening is set to off in the menus, those are the only changes and the red in the photos (jpeg + raw) looks very natural.

I've found that up to 3200 and even at slow shutter speeds noise is more manageable in PP than when all that stuff is done in camera. I also notice no artifacts in my skies with these settings off as well as no sharpening artifacts which I had seen in the past especially with high contrast subjects.

I wonder if the problem isn't aperture or monitor calibration?

6BQ5 · 01-12-2014, 05:35 PM

It's not so much how reds are displayed but how they are recorded - at least in my case. Of all colors that tend to blow out (i.e. Highlight all "hot" areas) red is the only one that does this to me. Otherwise they look very saturated. This is even in my DNG files so I think it's the sensor being very sensitive to red.

IchabodCrane · 01-12-2014, 07:50 PM

Originally posted by geru2000

I also own the K30 but experience no problems with shooting reds. In fact I was playing with the camera this afternoon and my subject was a red solo cup (seriously). Shot in bright and sharpening set to -3 or 4 all noise reduction and sharpening is set to off in the menus, those are the only changes and the red in the photos (jpeg + raw) looks very natural.

I've found that up to 3200 and even at slow shutter speeds noise is more manageable in PP than when all that stuff is done in camera. I also notice no artifacts in my skies with these settings off as well as no sharpening artifacts which I had seen in the past especially with high contrast subjects.

I wonder if the problem isn't aperture or monitor calibration?

Monitor calibration issues can't explain why an OOC JPEG looks much different than the JPEG produced by straight software conversion of the RAW file. In your tests of the cup, do the OOC JPEGs look the same as the RAWs side-by-side?

Steve.Ledger · 01-13-2014, 03:50 PM

As I mentioned, get you exposure correct - because it isn't.
See how much difference that makes for you.

IchabodCrane · 01-13-2014, 08:15 PM

Originally posted by Steve.Ledger

As I mentioned, get you exposure correct - because it isn't.
See how much difference that makes for you.

Steve, I followed the advice of several here plus some of my own learned experience to come up with the -1 exposure compensation. I and others have many clipped shots of red from leaving the metering at zero. It's fair to say my shot is underexposed but your mod bears surprisingly little resemblance to the plant I'm staring at.

Steve.Ledger · 01-16-2014, 10:40 PM

Well, of course I don't have your Poinsettia in front of me do I, but I am familiar with them.
But my point was not to guess what your real-world subject looks like, but to help you with getting a better looking image.
All I'm trying to say is that it's common for the red channel to blow out a bit but you can fix this with better exposures.
Sorry if I miffed you off - only trying to be helpful (which I assume is why you are here

)

IchabodCrane · 01-17-2014, 08:00 AM

Originally posted by Steve.Ledger

Well, of course I don't have your Poinsettia in front of me do I, but I am familiar with them.
But my point was not to guess what your real-world subject looks like, but to help you with getting a better looking image.
All I'm trying to say is that it's common for the red channel to blow out a bit but you can fix this with better exposures.
Sorry if I miffed you off - only trying to be helpful (which I assume is why you are here

)

Steve, thanks for your responses and, no, I'm not miffed. I hope I didn't do that to you, either. I suppose this is my thinking.... the only way I know of to avoid the red channel blow out (with these kinds of subjects) is to underexpose which leaves us with the task of correcting the JPEG in PP. If that's the solution, what's the point of recording in JPEG in the first place? We can all do the same more effectively and almost as easily with the RAW. This is why I wish Ricoh/Pentax would address some of these issues with their JPEG engine.

altopiet · 01-17-2014, 08:19 AM

Originally posted by IchabodCrane

Set the JPEG output to Bright with -1 Saturation. A couple other little tweaks in WB, too. Most important, shot was taken with -1 EV to avoid blowing out the reds which was successful as judged by the RAW file. Here is the OOC JPEG (1st image) compared to what Aperture converted to a JPEG from RAW without any adjustment (2nd image). For reference (and a little surprisingly) setting the camera to Natural produced even muddier images. If Apple can handle this well, why can't Pentax?

I actually had the same problem with my K-30, and a red rose, and experimented, taking the RAW image and started to play around with the Jpeg settings until I got something that almost matched it, and that was Natural with contrast +1.....as already said, it's all subjective, you just have to play around with the settings till you find what you like, that's why they give you quite a few options to make changes to the settings.

01-11-2014, 05:46 PM	#17
Steve.Ledger Veteran Member Join Date: Oct 2009 Location: Far North Qld Posts: 3,301	First of all, well underexposed. Look at the histogram, it's all to the left. Get your exposure correct and the red plus detail will be much better. Also check that NR is 'off'. NR will often muddy the waters. I'd also change the parameters of the colour styles to suit your taste. However, all is not lost - I dropped your JPG into FASTSTONE, corrected the exposure, lowered the blue channel and added some contrast. The detail seems to be there and the colour looks fine to me (on my IPS monitors). What do you think? Last edited by Steve.Ledger; 08-10-2014 at 10:12 PM.

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01-11-2014, 03:45 PM	#16
Rondec Loyal Site Supporter Join Date: Mar 2009 Location: Gladys, Virginia Photos: Gallery Posts: 27,663	I don't really worry about jpeg engine. Photos worth keeping are worth tweaking at least a little bit and I am better at doing that than the camera (cause I'm smarter, I guess). I know there are arguments about RAW versus jpeg all the time, but I am a RAW shooter all of the way.

01-11-2014, 09:51 PM	#18
6BQ5 Veteran Member Join Date: Jun 2013 Location: Nevada, USA Photos: Albums Posts: 3,348	My K-30 has a hard time with reds too. I don't know why. Any other shade and color is fine though. I cringe when I go out with my kids on a hike and they choose to wear red shirts! It's going to be a tough evening with Aperture then!

01-12-2014, 05:32 PM	#19
geru2000 Senior Member Join Date: Jan 2009 Location: Watertown, NY Posts: 267	Originally posted by 6BQ5 My K-30 has a hard time with reds too. I don't know why. Any other shade and color is fine though. I cringe when I go out with my kids on a hike and they choose to wear red shirts! It's going to be a tough evening with Aperture then! I also own the K30 but experience no problems with shooting reds. In fact I was playing with the camera this afternoon and my subject was a red solo cup (seriously). Shot in bright and sharpening set to -3 or 4 all noise reduction and sharpening is set to off in the menus, those are the only changes and the red in the photos (jpeg + raw) looks very natural. I've found that up to 3200 and even at slow shutter speeds noise is more manageable in PP than when all that stuff is done in camera. I also notice no artifacts in my skies with these settings off as well as no sharpening artifacts which I had seen in the past especially with high contrast subjects. I wonder if the problem isn't aperture or monitor calibration?

01-12-2014, 05:35 PM	#20
6BQ5 Veteran Member Join Date: Jun 2013 Location: Nevada, USA Photos: Albums Posts: 3,348	It's not so much how reds are displayed but how they are recorded - at least in my case. Of all colors that tend to blow out (i.e. Highlight all "hot" areas) red is the only one that does this to me. Otherwise they look very saturated. This is even in my DNG files so I think it's the sensor being very sensitive to red.

01-12-2014, 07:50 PM	#21
IchabodCrane Veteran Member Join Date: Sep 2012 Photos: Gallery \| Albums Posts: 1,728 Original Poster	Originally posted by geru2000 I also own the K30 but experience no problems with shooting reds. In fact I was playing with the camera this afternoon and my subject was a red solo cup (seriously). Shot in bright and sharpening set to -3 or 4 all noise reduction and sharpening is set to off in the menus, those are the only changes and the red in the photos (jpeg + raw) looks very natural. I've found that up to 3200 and even at slow shutter speeds noise is more manageable in PP than when all that stuff is done in camera. I also notice no artifacts in my skies with these settings off as well as no sharpening artifacts which I had seen in the past especially with high contrast subjects. I wonder if the problem isn't aperture or monitor calibration? Monitor calibration issues can't explain why an OOC JPEG looks much different than the JPEG produced by straight software conversion of the RAW file. In your tests of the cup, do the OOC JPEGs look the same as the RAWs side-by-side?

01-13-2014, 03:50 PM	#22
Steve.Ledger Veteran Member Join Date: Oct 2009 Location: Far North Qld Posts: 3,301	As I mentioned, get you exposure correct - because it isn't. See how much difference that makes for you.

01-13-2014, 08:15 PM	#23
IchabodCrane Veteran Member Join Date: Sep 2012 Photos: Gallery \| Albums Posts: 1,728 Original Poster	Originally posted by Steve.Ledger As I mentioned, get you exposure correct - because it isn't. See how much difference that makes for you. Steve, I followed the advice of several here plus some of my own learned experience to come up with the -1 exposure compensation. I and others have many clipped shots of red from leaving the metering at zero. It's fair to say my shot is underexposed but your mod bears surprisingly little resemblance to the plant I'm staring at.

01-16-2014, 10:40 PM	#24
Steve.Ledger Veteran Member Join Date: Oct 2009 Location: Far North Qld Posts: 3,301	Well, of course I don't have your Poinsettia in front of me do I, but I am familiar with them. But my point was not to guess what your real-world subject looks like, but to help you with getting a better looking image. All I'm trying to say is that it's common for the red channel to blow out a bit but you can fix this with better exposures. Sorry if I miffed you off - only trying to be helpful (which I assume is why you are here )

01-17-2014, 08:00 AM	#25
IchabodCrane Veteran Member Join Date: Sep 2012 Photos: Gallery \| Albums Posts: 1,728 Original Poster	Originally posted by Steve.Ledger Well, of course I don't have your Poinsettia in front of me do I, but I am familiar with them. But my point was not to guess what your real-world subject looks like, but to help you with getting a better looking image. All I'm trying to say is that it's common for the red channel to blow out a bit but you can fix this with better exposures. Sorry if I miffed you off - only trying to be helpful (which I assume is why you are here ) Steve, thanks for your responses and, no, I'm not miffed. I hope I didn't do that to you, either. I suppose this is my thinking.... the only way I know of to avoid the red channel blow out (with these kinds of subjects) is to underexpose which leaves us with the task of correcting the JPEG in PP. If that's the solution, what's the point of recording in JPEG in the first place? We can all do the same more effectively and almost as easily with the RAW. This is why I wish Ricoh/Pentax would address some of these issues with their JPEG engine.

01-17-2014, 08:19 AM	#26
altopiet Veteran Member Join Date: Sep 2010 Location: The Gem of the Karoo, South Africa Photos: Gallery \| Albums Posts: 2,307	Originally posted by IchabodCrane Set the JPEG output to Bright with -1 Saturation. A couple other little tweaks in WB, too. Most important, shot was taken with -1 EV to avoid blowing out the reds which was successful as judged by the RAW file. Here is the OOC JPEG (1st image) compared to what Aperture converted to a JPEG from RAW without any adjustment (2nd image). For reference (and a little surprisingly) setting the camera to Natural produced even muddier images. If Apple can handle this well, why can't Pentax? I actually had the same problem with my K-30, and a red rose, and experimented, taking the RAW image and started to play around with the Jpeg settings until I got something that almost matched it, and that was Natural with contrast +1.....as already said, it's all subjective, you just have to play around with the settings till you find what you like, that's why they give you quite a few options to make changes to the settings.