Author Topic: Black screen on photo preview unless zoomed in  (Read 6109 times)

Offline ybp

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Black screen on photo preview unless zoomed in
« on: April 18, 2015, 10:33:54 PM »
Photo Mechanic is randomly showing me a black screen on photos. There is nothing I can do to refresh or reload the image and make the black screen go away.

Nothing whatsoever is wrong with the photos themselves.

The photos are on a Synology NAS with an extremely high speed connection (only 10% of the connection bandwidth is being used at most).

This is a screenshot of the behavior:

http://dropoff.us/private/1429421183-1-ScreenShot2015-04-19at12.25.37AM.png

Zooming in (e.g., by typing Z) will show the photo correctly. But pushing Z again to zoom back out returns to a black screen. The histogram also shows pure black.

The problem has been happening for quite a while, but is getting extremely frustrating this past week due to the number of photos I am working with.

I have found other reports of the same behavior on these forums, but no one ever seemed to follow up on the problem.


Offline Kirk Baker

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Re: Black screen on photo preview unless zoomed in
« Reply #1 on: April 19, 2015, 10:08:37 AM »
Photo Mechanic is randomly showing me a black screen on photos. There is nothing I can do to refresh or reload the image and make the black screen go away.

Nothing whatsoever is wrong with the photos themselves.

The photos are on a Synology NAS with an extremely high speed connection (only 10% of the connection bandwidth is being used at most).

This is a screenshot of the behavior:

http://dropoff.us/private/1429421183-1-ScreenShot2015-04-19at12.25.37AM.png

Zooming in (e.g., by typing Z) will show the photo correctly. But pushing Z again to zoom back out returns to a black screen. The histogram also shows pure black.

The problem has been happening for quite a while, but is getting extremely frustrating this past week due to the number of photos I am working with.

I have found other reports of the same behavior on these forums, but no one ever seemed to follow up on the problem.

Go to the Help menu and choose "Reveal Support Data..." from the menu.  When the Finder comes forward, it will have a zipped log file selected.  Post that file here.  Use the 'Attachments and other options' link when you're composing your reply to this message and there you'll be able to upload your zipped log file.

Thanks,

-Kirk

Offline ybp

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Re: Black screen on photo preview unless zoomed in
« Reply #2 on: April 19, 2015, 08:11:32 PM »
I'm attaching this file. An example of a photo showing up as black is the file 2N0A9381.JPG (I just reopened PM and scrolled till a file appeared black which took only a few frames).

Even when I restart, the files still show as black. I have already checked for any things like the file being locked or "uchg" being set, etc. (Which probably wouldn't have affected anything, anyway.)

The files that are affected work perfectly in all other programs, and in zooming with PM. They only show as black when I am previewing the files at standard size. But this makes PM useless for me.

The problem does go away when I change resolution to 1080P. But I'm using a 4K monitor to avoid needing to zoom. Time is of essence, which is the whole point of PM and 4K. So if I have to go to 1080P to use PM, then it's useless.

Update: a quick grep of the PM.log file shows a majority of 7D Mark II images being affected, and some Nikon D810 images. But there are no 1D X images or 5D Mark III images, which are equally represented in my workflow. Could this be a lack of support for the 7D Mark II and D810, and perhaps JPEG files from newer camera bodies in general?


[attachment deleted by admin]
« Last Edit: April 19, 2015, 08:15:28 PM by ybp »

Offline Kirk Baker

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Re: Black screen on photo preview unless zoomed in
« Reply #3 on: April 19, 2015, 08:14:37 PM »
I'm attaching this file. An example of a photo showing up as black is the file 2N0A9381.JPG (I just reopened PM and scrolled till a file appeared black which took only a few frames).

Even when I restart, the files still show as black. I have already checked for any things like the file being locked or "uchg" being set, etc. (Which probably wouldn't have affected anything, anyway.)

The files that are affected work perfectly in all other programs, and in zooming with PM. They only show as black when I am previewing the files at standard size. But this makes PM useless for me.

The problem does go away when I change resolution to 1080P. But I'm using a 4K monitor to avoid needing to zoom. Time is of essence, which is the whole point of PM and 4K. So if I have to go to 1080P to use PM, then it's useless.

Photo Mechanic is running out of memory.  What are your Caching settings, particularly your Memory Cache setting?  If it is greater than 512 MB, then reduce it to 512MB.  More isn't always better, especially when your screen resolution is so large.

-Kirk

Offline ybp

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Re: Black screen on photo preview unless zoomed in
« Reply #4 on: April 19, 2015, 08:18:01 PM »
Activity Monitor shows I have more than 8 GB of memory free. I will try your suggestion and set the memory cache to 512 MB...

The photos still show up as black.

P.S. thanks for the incredibly fast response.


Offline ybp

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Re: Black screen on photo preview unless zoomed in
« Reply #5 on: April 19, 2015, 08:26:35 PM »
I got it to work now.

I clicked both "Empty now" buttons on the screenshot that I attached, and then I changed the memory size back to 1024. Now I am able to see some of the photos that were just black a moment ago.

Perhaps PM ran out of memory sometime in the past and then cached the black previews and never recreated them even when it had enough memory once again (such as after relaunching it).

There needs to be a one-key option to refresh the current image rather than use a cached version, in case the cached version is black. Right now there is no option I could find to reload the preview image from disk, other than to zoom in on it.

Thanks for your help. I suppose I should have tried the "empty now" buttons earlier, but there is a still a bug that exists, because the black images were never going away after many launches, and PM should have detected that they were black and then tried again on the individual images rather than making me empty the entire cache. (Changing the memory size alone did not affect the issue. Only emptying the cache took the black images away.)




[attachment deleted by admin]
« Last Edit: April 19, 2015, 08:30:15 PM by ybp »

Offline Kirk Baker

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Re: Black screen on photo preview unless zoomed in
« Reply #6 on: April 19, 2015, 08:50:58 PM »
I got it to work now.

I clicked both "Empty now" buttons on the screenshot that I attached, and then I changed the memory size back to 1024. Now I am able to see some of the photos that were just black a moment ago.

Perhaps PM ran out of memory sometime in the past and then cached the black previews and never recreated them even when it had enough memory once again (such as after relaunching it).

There needs to be a one-key option to refresh the current image rather than use a cached version, in case the cached version is black. Right now there is no option I could find to reload the preview image from disk, other than to zoom in on it.

Thanks for your help. I suppose I should have tried the "empty now" buttons earlier, but there is a still a bug that exists, because the black images were never going away after many launches, and PM should have detected that they were black and then tried again on the individual images rather than making me empty the entire cache. (Changing the memory size alone did not affect the issue. Only emptying the cache took the black images away.)

Please set your Memory Cache to 512 MB.  1024 MB is too large when running on a high-DPI screen.

-Kirk

Offline ybp

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Re: Black screen on photo preview unless zoomed in
« Reply #7 on: April 19, 2015, 09:03:44 PM »
I got it to work now.

I clicked both "Empty now" buttons on the screenshot that I attached, and then I changed the memory size back to 1024. Now I am able to see some of the photos that were just black a moment ago.

Perhaps PM ran out of memory sometime in the past and then cached the black previews and never recreated them even when it had enough memory once again (such as after relaunching it).

There needs to be a one-key option to refresh the current image rather than use a cached version, in case the cached version is black. Right now there is no option I could find to reload the preview image from disk, other than to zoom in on it.

Thanks for your help. I suppose I should have tried the "empty now" buttons earlier, but there is a still a bug that exists, because the black images were never going away after many launches, and PM should have detected that they were black and then tried again on the individual images rather than making me empty the entire cache. (Changing the memory size alone did not affect the issue. Only emptying the cache took the black images away.)

Please set your Memory Cache to 512 MB.  1024 MB is too large when running on a high-DPI screen.

-Kirk

Could you please elaborate and explain the real reason(s) WHY you suggest this for everyone's sake using PM?

The reason I ask is that without a reason what you suggest makes no sense, but I am sure you have good reasons based on how PM processes images.

I saved and invested over $4,000 on a computer easily able to handle memory-intensive tasks and high resolutions, and so I don't see any reason why I shouldn't make use of its capabilities.

FYI: Changing the memory cache size did nothing to eliminate the black images. Only emptying the disk cache got rid of them. I emptied the sort cache, too, but I don't know if that did anything or not.

If you are aware of a PM bug preventing 1024 MB memory cache from being used, such as if you know for a fact it is the cause of the black images, or other good reasons, I will be happy to change my settings back to 512 MB.


Offline Kirk Baker

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Re: Black screen on photo preview unless zoomed in
« Reply #8 on: April 19, 2015, 10:16:33 PM »
Sure.  Photo Mechanic is a 32-bit application.  As such, it can only ever access 4 GB of memory.  Some portion of that memory is used up by the application's code, the libraries it uses, and various data structures that are used to hold the metadata for your images.  The rest of the memory can be used for caching and for in-memory images.  When you have an extremely large resolution screen like yours, having a large memory cache leaves little memory left to load and scale images for your screen.  Making the memory cache smaller leaves more room for image manipulation.

The images that were black were likely images that were prepared for display that failed to load because PM was running out of available memory.  Those images were written to the disc cache and since your settings were set to not empty the cache on exit, they persisted.  Once you forced them to be deleted the problem disappeared, but it is likely that unless you set your memory cache to 512 MB as I suggested, the problem will return.

I'm sorry for the short answer earlier, it is a Sunday evening and I try to help people over the weekend but family comes first.

-Kirk

Offline ybp

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Re: Black screen on photo preview unless zoomed in
« Reply #9 on: April 20, 2015, 09:20:55 PM »
Thank you. I appreciate the explanation. I went back to 512 MB to give Photo Mechanic more free memory within its 4 GB maximum.

Hopefully there will be a 64-bit version soon.

I'm also anxiously awaiting the full database solution that your website mentioned at the time I ordered near the end of last year.

Lightroom is so glacial. Even if version 6 is twice as fast, it will be 50 times too slow for me. Picasa, with its Google technology, is 100x faster and has an incredible but buggy database system (gets corrupted after about 200,000 photos, and I have 1.6 million in the past 16 years).

So PM is my only hope for a solution that meets my speed needs and data needs without being buggy and consumer-oriented like Picasa. It will definitely need to be 64-bit to manage the volume of photos I have (mostly JPEGs, but still 10 TB).

Thanks again, and I just wanted to include the note that I'm anxiously awaiting your database solution, along with many others.