Does anybody understand projectors?

[Geoff F]

Quick update. A friend has been giving talks about his life to various organisations. I sorted out some of his old photographs and put them on a flash drive. Some places have a wall sized screen so he just inserts the stick and everything works well. For other venues, he was given an old projector which worked OK some of the time, using a laptop as source, but that projector had an occasional colour fault; so I persuaded him to invest in a new projector and he purchased an Epson EBS41.

Now with his new equipment, he couldn't get any images to show. Image source is a flash drive inserted directly into the projector. After a bit of work I managed to get most of them to appear but nothing in portrait mode (eg, square, 2 x 3 or 4 x 5 ratio). My attempt at a solution was to create a new black background image in 3 x 2 ratio with the problem image pasted on to the background. Image was 1200 x 800 pixels at 96 ppi jpeg. This worked for most images.

But nothing scanned in greyscale with appear. My recent colour photos will not show in 3 x 2 ratio but a crop to 16 x 9 works (same 1200 x 800 ratio).

Tomorrow, I will try a B&W scan in srgb mode to see if that works but I don't understand what is happening and I haven't found the instruction information to be of any help.

Also, I am getting worried about my greyscale scans. I have scanned over 1,000 images for the local history society and some are to be used for a presentation in two weeks time. Using a different projector through a laptop. Will they work? We will need to do an urgent test.

[Manfred M]

Most projectors are RGB devices, so gray scale could be a problem.

Have you tried running it through a laptop, rather than plugging the flash drive directly into the projector? I've run into some direct connection devices that limit the flash drive to very low capacity; my PVR, for instance, will not play any flash drive that has more than 4GB capacity.

[Geoff F]

That is one idea which I had in mind, Manfred, but it will mean my friend bringing along his laptop to connect. He was running the old projector that way with no problems and all images worked when using a memory stick through the computer.

I have done a bit more messing around today and I'm even more confused now. The flash drive is 4GB and the images occupy only 104MB.

Some images show a thumbnail but will be rejected by the projector. Others don't have a thumbnail, just a file name, but they work perfectly on the projected screen. No difference between JPEG and PNG.

From 60 images on the flash drive 17 won't show but the others are fine and at the moment I can't see any obvious differences between them. I am trying to save problem images to the flash drive by going through the Export settings to see if I can find any difference that way.

4 x 3 and widescreen ratio seems to work best but some other sizes show perfectly while others are rejected so at the moment I am just blundering around taking two steps backward for each one forward.

[Geoff F]

Went back to the original images this afternoon and tried again. Same result; Save As using Jpeg gives a thumbnail but no projected image. Using Export settings (with or without the convert to sRGB option) will project an image but no thumbnail, just a file name. Same thing when using recently created images.

Perhaps working from file names will be the only option but I am trying to keep things simple because my friend has little computer knowledge.

[Manfred M]

Have you checked to make sure that all the images are at or below the native resolution of the projector? I know the one I use can have issues with images that are greater than 1920 x 1080 pixels.

[royent]

Recommended image size by PAGB ( UK ) is 1600 x 1200 pixels RGB
Roy

[loosecanon]

But why direct from a memory stick?
Use a laptop and you can calibrate for better colour accuracy.
use powerpoint and similar software and you can easily jump to a slide in questions, and with presenter view you see the image, next image to be shown (how often have we said as the image comes up, "ah yes I forgot this image" or similar expressions). You can also see notes and even have a pointer on the screen, all whilst facing the audience.
Powerpoint enables much better presentations. It also avoids that real problem when an image collection is copied to a memory stick and the order is changed.

[Manfred M]

Recommended image size by PAGB ( UK ) is 1600 x 1200 pixels RGB
Roy

Which has nothing to do with the issue that Geoff is asking about.

[Geoff F]

Thanks for the suggestions.

All problem images have been resized to 1024 x 768 pixels at 96 ppi JPEG which is recommended size for this projector. Those which do not conform to that size ratio have been pasted onto a black blank background of that size.

So why do some images show in the projected view while others do not appear and I can't work out what is the difference between them. Also why do the failures work when copied to the flash drive using the Export As option; although the projected thumbnail images are replaced by filenames on those images.

I have tried changing the projector image settings to sRGB but that didn't make any difference.

My friend had been using his old projector coupled with a laptop which worked with all images but there was a variable colour problem with that projector. He isn't technically minded when it comes to computer stuff so this was an idea which would simply matters. When he goes to some venues, which have a massive screen, he simply plugs in his flash drive and everything works fine. This new projector which has a flash drive function was an attempt to coordinate everything into the simplest option for all occasions.

At the moment, it looks as though he will have to work with the thumbnails being a mixture of images and filenames which is sort of OK until after his talk when questions are asked and he needs to refer back to a particular image. Yes, that is still workable when he can find the image again but it would be so much easier and more professional if he could instantly find the required thumbnail.

Also, this has roused my curiosity so I am looking for an answer to something which has beaten my limited technical knowledge.