Why do large files look pixelated

**barondla** · 10-26-2020, 07:53 PM

Using Pentax/Silky Pix DCU 5 on a 7-8 year old Dell i5 4gb ram desktop with Dell 24" monitor. Browser mode looks fine, but switching to laboratory mode PEF Raw file appears kind of pixelated with white specks looking like dandruff. Noticed this a small bit when I received the Pentax K-1 last year. With the 645Z it's really bad. If I save the image as tiff or jpeg, it looks fine when reopened. The 2 year old Dell 17" i5 8gb laptop looks normal.

What is causing this? Too little Ram? Video card? Monitor limitations?

I'm planning on buying a new desktop next year, but need time to research what I want.

Thanks,
barondla

**bwgv001** · 10-26-2020, 09:00 PM

screenshots? what happens when you zoom in? what is the monitor resolution?

**ramseybuckeye** · 10-26-2020, 09:05 PM

It does sound as if it could be the monitor resolution, but more likely video card.

maw · 10-26-2020, 09:06 PM

Originally posted by barondla

Using Pentax/Silky Pix DCU 5 on a 7-8 year old Dell i5 4gb ram desktop with Dell 24" monitor. Browser mode looks fine, but switching to laboratory mode PEF Raw file appears kind of pixelated with white specks looking like dandruff. Noticed this a small bit when I received the Pentax K-1 last year. With the 645Z it's really bad. If I save the image as tiff or jpeg, it looks fine when reopened. The 2 year old Dell 17" i5 8gb laptop looks normal.

Hi,

Why don't you give it a try without the need to install any software, open from the browser Photopea (or Rawteraphee freeware) and then try to open the files mentioned,
then see if the defect persists or has disappeared.

In the first case it could be some driver, so you could reinstall it, otherwise it could be the video card, I hope not.

Photopea

steephill · 10-27-2020, 04:35 AM

What happens if you connect the desktop screen to the laptop? That check will help eliminate one variable. I suspect that having only 4GB isn't helping much. I upgraded my 10 year old i5 from 8 to 16GB this year and it definitely helped.

antipattern · 10-27-2020, 04:51 AM

Is this potentially related to the preview image embedded in the RAW file? Pentax cameras put a low resolution JPEG into the RAW so that the file can be previewed quickly without loading the entire file.

When I load my RAWs into Aperture (bless, it still works...) it first loads up the preview image with similar issues as you describe. Once it has processed the file, it creates a new preview in its library with better quality.

I wonder whether Silkypix is doing something similar but might not create a high quality image on older computers. Maybe there's a setting for that, too.

**ehrwien** · 10-27-2020, 05:31 AM

4 GB RAM is really not much. Apart from the image and image previews, the operating system already uses a good portion of it and the imaging software as well. Anything else running at the same time will further stress the situation. Could very well be just the RAM, I think. I wouldn't go below 16 GB for a new machine today, and for K-1 and 645 files you'd probably best be looking at 32 GB (and perhaps even above).

Have you tried waiting a while after switching to laboratory mode to see if it finishes properly loading the image after some time? Say 5 minutes? Of course that's far from any enjoyable experience for editing pictures, but just to see if it finishes after a little while. Could just take some time to process the changes that the standard profile applies to images when they are first loaded. (CPU)
It could also be the video card being overwhelmed. The monitor seems unlikely if you can see properly in browser mode.

I'd connect the laptop to the larger monitor and edit the pictures (at least the 645 ones) on the laptop until you have your new desktop. There are some great options on the market for every budget.

**barondla** · 10-27-2020, 11:47 PM

Thanks for the help everyone. Pixelation doesn't clear up with 5 minutes or more. Perhaps DCU5 requires more memory.

RawTherapee is now on the desktop and there isn't any pixelation. Depending on how RawTherapee works, it may have fixed the problem. When a Raw file is opened is it a small file like in DCU5, or is it the laboratory size? DCU5 displays browser images fine.

PEF looks very soft in RawTherapee. Preferences probably need to be adjusted. But, I'm not seeing any difference with sharpening. Exposure, color balance, etc are working as expected. Is there some trick I'm missing?

Thanks,
barondla

10-26-2020, 07:53 PM	#1
barondla Site Supporter Join Date: Sep 2006 Location: midwest, United States Photos: Gallery \| Albums Posts: 5,714	Why do large files look pixelated Using Pentax/Silky Pix DCU 5 on a 7-8 year old Dell i5 4gb ram desktop with Dell 24" monitor. Browser mode looks fine, but switching to laboratory mode PEF Raw file appears kind of pixelated with white specks looking like dandruff. Noticed this a small bit when I received the Pentax K-1 last year. With the 645Z it's really bad. If I save the image as tiff or jpeg, it looks fine when reopened. The 2 year old Dell 17" i5 8gb laptop looks normal. What is causing this? Too little Ram? Video card? Monitor limitations? I'm planning on buying a new desktop next year, but need time to research what I want. Thanks, barondla

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10-26-2020, 09:00 PM	#2
bwgv001 Site Supporter Join Date: Aug 2015 Location: Alabama Photos: Gallery Posts: 697	screenshots? what happens when you zoom in? what is the monitor resolution?

10-26-2020, 09:05 PM	#3
ramseybuckeye Site Supporter Join Date: Apr 2009 Location: Hampstead, NC Photos: Gallery Posts: 17,292	It does sound as if it could be the monitor resolution, but more likely video card.

10-26-2020, 09:06 PM	#4
maw Pentaxian Join Date: Feb 2014 Location: Sassari (Italy) Posts: 1,118	Originally posted by barondla Using Pentax/Silky Pix DCU 5 on a 7-8 year old Dell i5 4gb ram desktop with Dell 24" monitor. Browser mode looks fine, but switching to laboratory mode PEF Raw file appears kind of pixelated with white specks looking like dandruff. Noticed this a small bit when I received the Pentax K-1 last year. With the 645Z it's really bad. If I save the image as tiff or jpeg, it looks fine when reopened. The 2 year old Dell 17" i5 8gb laptop looks normal. Hi, Why don't you give it a try without the need to install any software, open from the browser Photopea (or Rawteraphee freeware) and then try to open the files mentioned, then see if the defect persists or has disappeared. In the first case it could be some driver, so you could reinstall it, otherwise it could be the video card, I hope not. Photopea

10-27-2020, 04:35 AM	#5
steephill Pentaxian Join Date: Nov 2018 Photos: Gallery Posts: 586	What happens if you connect the desktop screen to the laptop? That check will help eliminate one variable. I suspect that having only 4GB isn't helping much. I upgraded my 10 year old i5 from 8 to 16GB this year and it definitely helped.

10-27-2020, 04:51 AM	#6
antipattern Senior Member Join Date: Apr 2012 Location: Berlin, Germany Photos: Albums Posts: 232	Is this potentially related to the preview image embedded in the RAW file? Pentax cameras put a low resolution JPEG into the RAW so that the file can be previewed quickly without loading the entire file. When I load my RAWs into Aperture (bless, it still works...) it first loads up the preview image with similar issues as you describe. Once it has processed the file, it creates a new preview in its library with better quality. I wonder whether Silkypix is doing something similar but might not create a high quality image on older computers. Maybe there's a setting for that, too.

10-27-2020, 05:31 AM	#7
ehrwien Site Supporter Join Date: May 2016 Posts: 2,782	4 GB RAM is really not much. Apart from the image and image previews, the operating system already uses a good portion of it and the imaging software as well. Anything else running at the same time will further stress the situation. Could very well be just the RAM, I think. I wouldn't go below 16 GB for a new machine today, and for K-1 and 645 files you'd probably best be looking at 32 GB (and perhaps even above). Have you tried waiting a while after switching to laboratory mode to see if it finishes properly loading the image after some time? Say 5 minutes? Of course that's far from any enjoyable experience for editing pictures, but just to see if it finishes after a little while. Could just take some time to process the changes that the standard profile applies to images when they are first loaded. (CPU) It could also be the video card being overwhelmed. The monitor seems unlikely if you can see properly in browser mode. I'd connect the laptop to the larger monitor and edit the pictures (at least the 645 ones) on the laptop until you have your new desktop. There are some great options on the market for every budget.

10-27-2020, 11:47 PM	#8
barondla Site Supporter Join Date: Sep 2006 Location: midwest, United States Photos: Gallery \| Albums Posts: 5,714 Original Poster	Thanks for the help everyone. Pixelation doesn't clear up with 5 minutes or more. Perhaps DCU5 requires more memory. RawTherapee is now on the desktop and there isn't any pixelation. Depending on how RawTherapee works, it may have fixed the problem. When a Raw file is opened is it a small file like in DCU5, or is it the laboratory size? DCU5 displays browser images fine. PEF looks very soft in RawTherapee. Preferences probably need to be adjusted. But, I'm not seeing any difference with sharpening. Exposure, color balance, etc are working as expected. Is there some trick I'm missing? Thanks, barondla