Lens Correction causes lines in the jpeg

[Rick Roberts]

Entering manual lens correction (A, B, C) causes lines to show up in the jpeg. There's a vertical line 10% in from the left, and a horizontal line 10% in from the top. How does one make the Corel development team aware of this?

[afx]

Hmm, can't reproduce that here ad hoc. What cam/lens and what parameters?
cheers
afx

[Rick Roberts]

I'm using a Pentax Q7, shooting RAW in DNG format. The lens correction factors are: 1st -.005, 2nd -.04, and 3rd +.006. I've posted an example picture at: http://l-g-photography.com/Pictures/Ash ... 001%29.jpg

You'll notice the lines are slightly curved in and mostly likely match the pincushion distortion of the lens. They're on the left side and top. If lens correction is disabled, the lines go away.

Any ideas?

Also, if you're shooting DNG, and entering manual correction factors, should it matter what camera or lens you're using? I wouldn't think the lens would come into play at all, but it seems like the camera too is taken out of the equation when the generic RAW data is converted to DNG.

[afx]

Looks like this is specific to the cam/file.

AS does not support generic DNGs, your Pentax file is a native DNG. It should show the lens info.

cheers
afx

[Rick Roberts]

Thank you for answering! Appreciated.

I'm still a little dense here. ASP has no problem opening and working with the Pentax DNG. Everything is good until entering those 3 lens correction factors. My understanding of those corrections is that they direct the shifting of pixels to correct for distortion. Once an image is loaded into ASP, why should it care who or what put it there? Shouldn't that pixel shifting be the same regardless of camera or lens?

Again, sorry for not understanding all of this.

[afx]

It should not matter. But, to me it looks like it is a tile border issue and that depends probably on the exact image size and potentially also on the previous processing of the file.

Can you take a show in PEF and DNG and see if that changes anything?

cheers
afx

[Rick Roberts]

I can not. The only options available with the Pentax Q series are jpg and DNG.