Scrambled Slideshow

[Ethan Welty]

MacBook Pro
Mac OS X 10.6.8
PM 4.6.8

When running my laptop to an external (Dell U2711) monitor, slideshow feature from Photo Mechanic is completely scrambled. Most of the screen is black, but pockmarked with small squares of jumbled pixels. I have no problem when using the slideshow on my laptop screen, and no other problem with the monitor.

Any ideas? I connect to the monitor with a Dual DVI cable to support its high resolution (2560 x 1440).

[Kirk Baker]

Ethan,

MacBook Pro
Mac OS X 10.6.8
PM 4.6.8

When running my laptop to an external (Dell U2711) monitor, slideshow feature from Photo Mechanic is completely scrambled. Most of the screen is black, but pockmarked with small squares of jumbled pixels. I have no problem when using the slideshow on my laptop screen, and no other problem with the monitor.

Any ideas? I connect to the monitor with a Dual DVI cable to support its high resolution (2560 x 1440).

No ideas.  I have a multi-monitor system (three monitors) and I can run the slideshow on any of the monitors with no issues.  My system is also running Mac OS X 10.6.8.

-Kirk

[Ethan Welty]

Hmm, I tried a few more things. And attached a screenshot. I should note that I can still move through the slideshow, and the 'scramble' changes for each image.

Unfortunately I don't have access to another external monitor to test this out with.

+ both laptop (internal) and external monitors active
slideshow on external - black and scrambled on external, artifacts sometimes also appear on internal
slideshow on internal - black and scrambled on internal, no effect to external

+ both monitors active, but mirrored...
works!

+ only external monitor active
black and scrambled

+ only internal monitor active
works!

The results are unaffected by the resolution setting of the external monitor. Or color profile.

[attachment deleted by admin]

[Kirk Baker]

Ethan,

Hmm, I tried a few more things. And attached a screenshot. I should note that I can still move through the slideshow, and the 'scramble' changes for each image.

Unfortunately I don't have access to another external monitor to test this out with.

+ both laptop (internal) and external monitors active
slideshow on external - black and scrambled on external, artifacts sometimes also appear on internal
slideshow on internal - black and scrambled on internal, no effect to external

+ both monitors active, but mirrored...
works!

+ only external monitor active
black and scrambled

+ only internal monitor active
works!

The results are unaffected by the resolution setting of the external monitor. Or color profile.

When mirrored, both screens end up having the same resolution?

-Kirk

[Ethan Welty]

Yes, when mirrored, the usable resolution of the external monitor is reduced (and black bands added) so that the external monitor matches the internal monitor in resolution and aspect ratio.

[Kirk Baker]

Ethan,

Yes, when mirrored, the usable resolution of the external monitor is reduced (and black bands added) so that the external monitor matches the internal monitor in resolution and aspect ratio.

OK, so that's not a real solution then.

I don't know why it would do what you're describing.  Unless we can reproduce this in house, I don't know how we'll be able to fix it.

-Kirk

[Ethan Welty]

Even stranger, I found a small LCD monitor at the office, and it works just fine. So now I'm suspecting this has something to do with the WQHD of the U2711 monitor, or the Dual DVI that is required maybe? Whatever would lead my computer's graphics card to speak to my monitor differently?

[Kirk Baker]

Ethan,

Even stranger, I found a small LCD monitor at the office, and it works just fine. So now I'm suspecting this has something to do with the WQHD of the U2711 monitor, or the Dual DVI that is required maybe? Whatever would lead my computer's graphics card to speak to my monitor differently?

Do you have any applications that use OpenGL (like games or other graphics intensive software) that you could try on this monitor?  Do they work fine?

The new slideshow in PM 4.6.8 uses OpenGL to take over the screen and present images.

-Kirk

[Ethan Welty]

Some updates:

+ PM 4.6.7 slideshow works properly on the external monitor
+ Tested a couple of OpenGL games, everything seemed to work as expected
+ Connected the external monitor with VGA cable (rather than with DVI-D cable, which is required to access the monitor's native resolution) and the slideshow worked in PM 4.6.8.

Do you have a DVI-D monitor handy at your office to try to replicate this?

[Kirk Baker]

Ethan,

Some updates:

+ PM 4.6.7 slideshow works properly on the external monitor
+ Tested a couple of OpenGL games, everything seemed to work as expected
+ Connected the external monitor with VGA cable (rather than with DVI-D cable, which is required to access the monitor's native resolution) and the slideshow worked in PM 4.6.8.

Do you have a DVI-D monitor handy at your office to try to replicate this?

All three of my monitors are connected via DVI-D cables.  I'd suspect it has something to do with the dual DVI-D going to a single monitor.

I have a recent vintage MacBookPro but I do not have a monitor that takes dual DVI-D.

-Kirk

[Ethan Welty]

I think you understood right, but just in case: By dual DVI-D I mean a dual link DVI-D (still a simple cable with two ends), which refers to a full set of pins for increased bandwidth.

see photo here:
single link:   http://www.datapro.net/products/dvi-d-single-link-digital-cable.html
dual link:   http://www.datapro.net/products/dvi-d-dual-link-digital-cable.html
(notice the extra pins)

[Kirk Baker]

Ethan,

I think you understood right, but just in case: By dual DVI-D I mean a dual link DVI-D (still a simple cable with two ends), which refers to a full set of pins for increased bandwidth.

see photo here:
single link:   http://www.datapro.net/products/dvi-d-single-link-digital-cable.html
dual link:   http://www.datapro.net/products/dvi-d-dual-link-digital-cable.html
(notice the extra pins)

Yes, I understand.  What does the other end of the cable that connects to your MacBookPro look like?

-Kirk

[Ethan Welty]

Dual link (full set of pins) at each end. My Macbook Pro has a native DVI port (it is from 2007), not one of those newfangled mini-DVI or whatnots.

[Kirk Baker]

Ethan,

Dual link (full set of pins) at each end. My Macbook Pro has a native DVI port (it is from 2007), not one of those newfangled mini-DVI or whatnots.

OK, mine is one of the newer ones that has the special Apple-only display port.  At any rate I don't have one of those > 1920 pixel wide displays.

-Kirk