Pentax K3 RAW files look erratic


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Bulent Celasun
Pentax K3 RAW files look erratic

I have been using LightZone since Stone Age! I am happy it survives.

Now I am on the verge of sparing a lot more time to processing my images and need a "consistent" workflow from now on. 

The consistency bit is new for me and makes me think about alternatives. My affair with AfterShotPro ended due to their lack of support for K3. 

Also, they do not seem to be as alive as our lovely "Zombie".

Perfect Effects seems more directed to the beginners and does not support Linux.

DarkTable's interface and logic requires me devote significant amount of time to understand it and use it effectively.

LightZone is still the application I understand best and use most. 

I use MS Windows only when absolutely necessary and Adobe products have never been on my radar.

...

Now, my problem. LZ opens many of my K3 RAW files acceptably. I mean, the default curve does not seem to ideal. (K5 files are processed without major problems). 

Still, I am able to deal with it and I can recover seemingly blown highligts most of the time with success.

LZ displays the embedded jpg nicely, by the way.

Problem 1 :

The raw images that need rotation (coded as such by the camera) is cropped during rotation into a square!

My solution : Open the said file in XnView and export as a tiff. However, this makes handling the highlights cumbersome and less effective. It also defeats the purpose in terms of a smooth and "consistent" workflow.(Those blown highligts are not really blown, by the way).

 

Problem 2 : 

This "always" happens with rotated images and occurs unexpectedly in some other images as well. There may be a repeatable pattern to this but I am not aware of it. The problem is the apllication of a terribly unsuitable RAW conversion curve to the image resulting in blown highlights when there are none even on the default jpegs. Other converters (Darktable, Raw Therapee) open those images without problems. So the problem seemingly resides within conversion process of LZ. 

 

Problem 3 :

When I finish processing my images (all of them, almost every time) and open them in other applications (including Gimp) histograms show an unused section at the leftmost part. My LZ blacks are not really black! So, I need to adjust the black point "after" the processing.

Apparently, all my problems are due to the application of an improper RAW conversion curve. 

I have tried to create my own curve, by the way, using Tex's advice but I failed.

I should be most grateful if you could be of help solving my problems described above.

 

 

 

tex
Bulent, sorry you're having a problem

I have some questions:

  1. Are you using the most current version of LZ?
  2. I'm assuming you are using PEF files, not DNG (Does the K3 allow for DNG?  I now have a Pentax 645Z, and I have been shooting DNG's.  There is no tone curve for me, just the Raw Adjustment Tool, but my raw files look fine.
  3. I am not having the rotation problem that you are.  I wonder why.....?

Glad to see you here, btw.  Obviously I, too, have stuck with LZ.  Hope we can help you.

Bulent Celasun
Tex,

Tex,

 

Thank you for your interest in my problem. 

>1. Are you using the most current version of LZ?

Yes.

>2. I'm assuming you are using PEF files, not DNG (Does the K3 allow for DNG?  I now have a Pentax 645Z, and I have been shooting DNG's.  There is no tone curve for me, just the Raw Adjustment Tool, but my raw files look fine.

K3 allows for DNG. As far as I know, operation-wise it is very similar to 645Z. 

I will try a DNG file ASAP and will inform the forum about the result. Are you saying that the Raw Adjustment Tool does not need a curve?

 

>3. I am not having the rotation problem that you are.  I wonder why.....?

I have no idea. I will be adding a screenshot soon. 

 

Bulent

 

 

 

Bulent Celasun
I will try to add an example

I will try to add an example of the rotation problem now (for a *.pef file)). 

...

 

 

Note that the curve is also applied resulting in serious highlight clipping. 

Bulent Celasun
UPDATE.

UPDATE.

I have made a new raw curve file following Doug Pardee's helpful YouTube video. 

It is applied to both PEF and DNG files from K3 automatically.

WITHOUT the curves, there is no serious clipping of the highligts.

Only the red channel highlights are seriously clipped. (Dark tones of the blue channel are also clipped)

Part of the clippings may be due to nature of my test image (suboptimal, uncontrolled dynamic range).

An exposure value of minus 0.75 seems to help cure the red channel clipping for this particular image (without the curve).

There is practically no difference between the results from the pef and dng files. 

So, a seemingly correctly prepared Raw Curve Profile causes excessive highlight clipping.

Should I just stop trying to use a curve?