Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-25-2015, 12:30 AM   #1
New Member




Join Date: Mar 2015
Posts: 7
645Z - Strange behaviour in Photoshop

Hi everyone,

I am using my 645Z in studio to do some beauty/Fashion work. My normal workflow is to import my DNG’s in Lightroom and then use LR to open the pictures in Photoshop. In LR I specified to use a 8bit conversion when entering into photoshop.

For beauty retouching I tend to use the Frequency Separation technique which consists of a Low layer to work on your color and a High Layer to work on the texture. Now here is where the strange behaviour pops in. In the Low (color) layer I use a blur to blend the colours together. Most of the time it’s a motion or Gaussian blur. When I do this with my 645Z files the results are just awful and nothing like I was used to have with my other cameras. However, as soon as I change the image mode back to 16 bit it is more or less ok (the results are still not up to what i was used to have).

Working in 16bit is not a big deal but as you know it tends to slow down the processing and also produces very large files to work with….

Ps. I have the same issue opening my files in Bridge before entering PS.

Anyone any ideas or suggestion on how to modify my workflow?

Thanks a lot

Frédéric

05-25-2015, 04:28 AM   #2
Pentaxian




Join Date: Sep 2011
Location: Nelson B.C.
Posts: 3,211
https://www.pentaxforums.com/forums/48-pentax-medium-format/289583-banding-st...ighlights.html

This thread describes some of the issues. You may be running into limitations of lightroom color spaces.

Post an example if possible.
05-25-2015, 05:11 AM   #3
Veteran Member
Kolor-Pikker's Avatar

Join Date: Dec 2014
Posts: 333
Can you show an example of what's wrong and what you expect it to look like? Kinda hard to go on just words. I've never done frequency separation, so I can't test it out myself.
The closest I have to frequency-based skin processing is the Portraiture plugin, but using it on an 8-bit studio portrait I don't see anything out of the ordinary.

That thread shows problems that I believe occur near the highlight limits of the camera, and with certain colors in the blue-magenta spectrum, strange if it applies to skin as well. I want to add that I myself never experienced what was described there.

Last edited by Kolor-Pikker; 05-25-2015 at 05:18 AM.
05-25-2015, 05:41 AM   #4
Pentaxian
MJSfoto1956's Avatar

Join Date: Dec 2013
Location: Boston
Posts: 1,285
it is well known that 8-bit images will posterize whenever there are subtle color blends (e.g. skies or softly-lit skin). Perhaps you never noticed it before? Or perhaps your lighting/makeup is "softer" these days?

Michael

05-25-2015, 06:00 AM   #5
Loyal Site Supporter
clackers's Avatar

Join Date: Jul 2013
Location: Melbourne
Photos: Albums
Posts: 7,704
QuoteOriginally posted by flanoizele Quote
In LR I specified to use a 8bit conversion when entering into photoshop.
Yikes!
05-25-2015, 06:12 AM   #6
Senior Member
fwbigd's Avatar

Join Date: Jun 2007
Location: Fort Worth TX
Posts: 298
First what version of Lighroom and Photoshop are you using? It appears that you are using Lightroom 1 form your post and color profiles were changed in version 3 I believe. If your not using the newest version of Lightroom CC (2015) and Photoshop CC (2014) you will not be getting the benefits of the 645z and the DNG raw file.


Check your color space priority and file format your using in Lightroom external editor preferences. Remember when you use the external editor in Lightroom you are either changing the file format to a TIFF or PSD for editing in Photoshop.
05-25-2015, 06:46 AM   #7
New Member




Join Date: Mar 2015
Posts: 7
Original Poster
Ok, let me try to clarify...

@Darryl, I am not using LR1, i have no clue what part of my post suggested this but I am using Photoshop CC (2014) and LR CC also.

With regards to colorspace I am used to use Prophoto RGB as this should be the largest color space available. I use 8 bits because of the fact that 16 bits slows down considerably and produces very large files.

The lightning I used yesterday was a beauty dish and a small softbox. Nothing out of the ordinary. We also used a Nikon D800 and there are no problems with the RAW files out of this camera.

As soon as I get home I will try to post an example of what I am talking about. Maybe that will help.

Thanks for all your reply's... I really appreciate this

Frédéric
05-25-2015, 07:32 AM   #8
Forum Member




Join Date: Apr 2015
Posts: 73
I also use Frequency Separation and have not had this issue. Have you tried restarting your computer? Sometimes your computer gives a glitch and a simple restart will restore it. I'm using the latest OS (Yosemite) on an iMac with Adobe CS6.

05-25-2015, 09:57 AM - 1 Like   #9
Senior Member
fwbigd's Avatar

Join Date: Jun 2007
Location: Fort Worth TX
Posts: 298
Sorry I miss read in "LR I" for LR1. My apology
05-25-2015, 10:37 PM   #10
Junior Member




Join Date: Jul 2012
Posts: 25
Hi there,
I can not help you with the seperation issue itself.

However I can help you with Prophoto. It is not recommended to use prophoto colorspace in 8 bit only. The color space is so large that it needs 16 bit. using 8 bit is asking for problems

good luck with your problem

Martin
05-26-2015, 02:47 AM   #11
Veteran Member
Kolor-Pikker's Avatar

Join Date: Dec 2014
Posts: 333
I'd probably not use ProPhoto for portraits at all actually, a lot of the extra color gamut you receive extends way beyond the visible spectrum, never mind any media you could wish to print the image on.
Your images won't suddenly gain or lose color pop or saturation by going from one space to another, you need to meet two conditions for the extra gamut to matter:
1. Your subject has colors that are saturated enough to make use of that extra space.
2. Your media can replicate those saturated colors.
Chances are most photos don't even meet criteria #1 unless you go crazy during post processing.

If you're photographing flowers or something similar, then go ahead and use ProPhotoRGB, it can actually matter there.

Last edited by Kolor-Pikker; 05-26-2015 at 11:49 PM.
05-26-2015, 09:12 PM   #12
Pentaxian
Thomasbrowphoto's Avatar

Join Date: May 2014
Location: NSW, Australia
Posts: 335
Can I suggest that you will generally need a larger blur radius with the 50mp files compared to say a 24-36mp files. Different resolutions react differently to certain filters in PS etc etc such as gaussian blurs. Hope this helps. Also I highly recommend leaving 8 bit editing and ONLY use 16 bit.
Tom
05-27-2015, 11:45 PM   #13
New Member




Join Date: Mar 2015
Posts: 7
Original Poster
Hello Tom, you are absolutely correct, the high resolution has an impact on these filters... However, in 16 bit mode I just can't find a way to use the Gaussian blur (nor the motion blur by the way). I really need to find a way to post an example to show you what it looks like... I should have some time to spend on this later today and will give it a try with a screenshot or something.

Frederic
06-01-2015, 03:58 AM   #14
Junior Member




Join Date: May 2014
Posts: 42
Using Profoto color space in 8bits doesnt make much sense. You will see a lot of banding all the time.
Surface blur in 16bit is very slow (depending on your settings), but you can speed it up using Medium filter with very similar results if you are in a hurry.
Headshot from 645Z, AdobeRGB 16b, surface blur 32/32 = 3-4 minutes on 6core MacPro (2014). Same Median +-20 sec and the only unusable part are the lips, which you should mask out anyway.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
645d, 645z, 645z photoshop, 645z strange behaviour, behaviour, blur, camera, files, layer, lr, medium format, photoshop, ps, results
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
Astrotracer O-GPS1 strange behaviour Vranx Pentax Camera and Field Accessories 10 09-23-2014 04:47 PM
Calling 645Z owners - testing dark frame behaviour Ed Hurst Pentax Medium Format 50 07-31-2014 05:28 PM
K5II - Strange behaviour ?!?! Sumit Floyd Chaterji Pentax SLR Lens Discussion 7 07-29-2014 02:19 AM
645Z and dark frame behaviour Ed Hurst Pentax Medium Format 3 05-14-2014 04:09 AM
K10D - Autofocus and Aperture strange behaviour lubosh.occ Troubleshooting and Beginner Help 13 04-12-2014 10:46 AM



All times are GMT -7. The time now is 11:11 PM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top