Pentax highlight clipping - JPG setting?

Grainbelt

Hopefully a simple question about the JPG engine and custom settings on my Pentax K200D.

I've been shooting RAW for the last year or so, having discovered a fair bit of extra dynamic range in both highlight and shadow detail in my K200D. Yesterday I had some time and took a number of identical images using various custom JPG settings in the camera to see if I can get a palatable out-of-camera result.

I eventually got a result that I can deal with, but it is still brighter (highlights only) than the RAW image. When I began shooting RAW, I changed the default ACR 4.4 settings and dropped the 'brightness' and 'contrast' sliders to zero, as I tend to need the DR and add contrast via curves adjustments later in my workflow.

Is there a 'brightness' setting in the JPG engine somewhere that I can change, or is this a limitation of the in-camera conversion process?

Current settings are:

Saturation +1
Hue 0
Contrast -3
Sharpness -1
Fine Sharpness -1

MarkR

If you're saying that the JPG highlights are brighter than your raw settings-- that's probably a tone curve that is being applied to the jpeg. You can probably match your raw to it in ACR by playing with the tone curve, but I don't think you're going to fix jpeg output without using photoshop.

What advantage does shooting jpg gives you?

Grainbelt

MarkR wrote: »

What advantage does shooting jpg gives you?

I've started taking my DSLR on motorcycle trips with me, and sometimes want to update friends with pics along the way. I only bring my netbook on those trips, and it doesn't have the processing power, memory, or software to work with RAW files. I back the card up to the camera almost daily anyway - figure I could shoot RAW+JPG and if the JPGs are ok, resize and post them very quickly. I'd still end up using the RAW files for my final culling, pp, and archiving.

I've also considered using the in-camera RAW development option at the last minute for any pics from that day I'd like to share, but that seems unnecessary since storage space isn't an issue.

I'm going to go out in the snow (helloooo, highlights) today with a couple of lenses and see how it works out.

Grainbelt

I wandered around the neighborhood a bit today to do some testing, and got some weird results. I'll post four photos below: the original JPG and RAW file, and edits of each.

EXIF is ISO 200, F8, 1/40, focal length 37.5mm on kit 18-55. AV mode, exposure +1/3, WB preset cloudy, matrix metering.

RAW file, uploaded to smugmug as a DNG with no changes.



The JPG out of camera




Edited RAW file: Exposure +1/2 stop, curves adjustment, Unsharp mask 150%, .7, 15



Edited JPG - curves adjustments to increase contrast, levels 3/252.




The finished files look about the same after adjustments, which I guess is what I was hoping for (I need to drop the saturation from 1 to 0 on in camera JPGS). The original JPG matches what I would expect from chimping the in-camera histogram when shooting, only to find the RAW file half a stop darker.

My issue with all this is that I can't trust the metering to give a consistent result. If I shoot a bit to the right on the histogram, I get properly exposed RAW file and a blown JPG. If I trust the camera, I get a nice JPG but have to boost the RAW file.

Am I going off the deep end here? I'm not a pixel peeper, I just want consistent results.

ziggy53

Grainbelt wrote: »

... My issue with all this is that I can't trust the metering to give a consistent result. If I shoot a bit to the right on the histogram, I get properly exposed RAW file and a blown JPG. If I trust the camera, I get a nice JPG but have to boost the RAW file.

Am I going off the deep end here? I'm not a pixel peeper, I just want consistent results.

First, there is no "standard" RAW conversion. The RAW converter used and the settings within will greatly affect the rendering and output. Default settings may or may not give you the desired results. The default settings will also typically vary per RAW file type.

Second, the in-camera JPG can likewise be adjusted by the user, without necessarily affecting the RAW file from the camera.

With those 2 variables it's easy to understand why you got the results we see.

Some cameras do record the camera's JPG settings along with the RAW files which can be read by the camera manufacturer's own RAW converter and that often yields closer results.

Additionally, camera metering and histogram interpretations in the camera generally don't exactly match most RAW software histograms of the same scenes.

It's best to run a lot of tests to determine the best settings for your RAW converter to closely match your initial expectations, and then save those settings as a profile if your converter allows. This can get you close very quickly as long as you use the profile. Some converter software allows you to save the new profile as the default profile, which can save a lot of time in getting you close to your goal.

Grainbelt

ziggy53 wrote: »

It's best to run a lot of tests to determine the best settings for your RAW converter to closely match your initial expectations, and then save those settings as a profile if your converter allows. This can get you close very quickly as long as you use the profile. Some converter software allows you to save the new profile as the default profile, which can save a lot of time in getting you close to your goal.

Thanks, Ziggy. That's where I am now. My RAW converter settings were initially based on contrasty daytime landscapes and maximizing DR, but that isn't proving useful for other situations.

When I open the file in ACR I have the option of ACR 4.4, camera default, Adobe standard, and embedded. I then can adjust a whole bunch of stuff and save the settings as the default. Just a matter of playing around now, I guess.

Yay! Camera nerd weekend! On the flipside, I got the in-camera JPG settings where I want them.

Thanks all.

MarkR

Grainbelt wrote: »

Thanks, Ziggy. That's where I am now. My RAW converter settings were initially based on contrasty daytime landscapes and maximizing DR, but that isn't proving useful for other situations.

When I open the file in ACR I have the option of ACR 4.4, camera default, Adobe standard, and embedded. I then can adjust a whole bunch of stuff and save the settings as the default. Just a matter of playing around now, I guess.

Yay! Camera nerd weekend! On the flipside, I got the in-camera JPG settings where I want them.

Thanks all.

I've tried all the different camera calibration profiles. The Adobe standard is supposed to be what it says-- Adobe calibrated against the camera. But my version of lightroom always was too magenta, which made skin tones nasty. I eventually bought an xrite color passport and used it to create my own dual-illuminant color profile. The net results were much more pleasing and believable colors. I did have problems with the x-rite tool, but Adobe labs has their own tool which I found to work better in my case.

Grainbelt

MarkR wrote: »

I've tried all the different camera calibration profiles. The Adobe standard is supposed to be what it says-- Adobe calibrated against the camera. But my version of lightroom always was too magenta, which made skin tones nasty.

I've been happy with the color rendition using the ACR 4.4 profile in PSE8 on my huey-calibrated monitor. My issue is primarily brightness / contrast issues. I'm sure I'll find a reasonable compromise.

Every time I think I figure something out, another complicating factor enters the frame. Sometimes I wish I could go back three years to my ignorant bliss. Then I look at those pics. :puke

Internaut

As a general principle (at least in my Olympus Experience), you can avoid clipping by shooting a fairly muted image (i.e low contrast and saturation which can be added back in PP) but a lot is going to depend immune specific JPEG processing of the camera. I'd say it's worth a try though.