Sunday, 9 June 2019

Taking Pictures of Computer Screens

I've been writing this blog for almost 10 years now, and most of the time it follows this same format. A paragraph of text, followed by a photograph, another paragraph, another photo etc. I take a lot of photos for each one of these, and try to get the best shots. But one thing I seem to be unable to do is take a decent photograph of a computer screen.
I have tried various options, different monitors, different cameras etc. but I've never quite got the hang of it.
Any time I use a CRT, it's usually a bit of a muddy picture with reflections etc. and I always have problems with empty screens with just text up in the top left corner, often resorting to photographing just that area.
Flash doesn't help here, as you just get a bright circle.
So it's a question of holding the camera still.
Even when I do get a half decent picture, there is often bits of the room reflected in the screen.
Or maybe a view out of the window.
Or worse, the photographer.
It's not just PETs. Same issues with a Commodore 1901 CRT monitor,
I have a small black and white CRT on the shelves above the workbench, useful for tuning into machines with only an RF output before composite video conversions etc.
That is very difficult to catch a decent photograph of for some reason it always seems to catch a partially drawn screen.
And even when I do, it's often not much use for blog posts where colour is relevant.
The oscilloscope below is likewise problematic for me to photograph.
Please note, all the pictures above are from actual blog posts. These were the best ones. These were the result of a process where I said, yes, that's the one I want to show off to the world. You can only imagine the state of all the ones I rejected.
I have had more luck with LCD monitors, where I can often get a usable shot.
There are more than their fair share of ropey ones though, and again, the mainly empty screen is a problem.
The camera also seems to have a blind spot around the light blue on dark blue default colours on the Commodore 64.
And in a few cases, I have resorted to changing the colour scheme on the C64 just to get a picture.
I've got a number of blog posts ready to go, but I've held them back in an attempt to get some better screenshots. So I've been trying some different things.
I did try getting a gooseneck camera mount, which sort of worked, but it still wobbles a bit when you press the button (and it doesn't have a remove shutter control). I also tried taking video on the camera, which sort of worked.
One option that seems to be popular to record video for the youtubes is to use a DVD Recorder. I have tried that a few times, it's a bit more involved as I need to connect it up, record it to the internal hard drive and transfer to DVD (or I think I can record direct to DVD-RW), then take the DVD to the PC and play it with VLC media player and take screenshots I can use on here.
That's not too bad. It's a bit involved, and unfortunately, neither of the two DVD recorders I have tried will accept NTSC signals, just displaying 'unsupported format' (or something like that). I suspect the hardware would be more than capable of doing it, but for commercial reasons or copyright protection etc. they block it.
But the PAL side of things is OK, but as with this sort of device, adds a bit of latency to the display. So that is an option, but I was hoping for a better one. The next option was a USB video capture card. I got a cheap one to try out (based on the theory that the more expensive ones probably used the same chipset, just in a better box?).
That plugs into the AV leads from the back of the computer being tested, and recorder directly to the computer. In some cases, I can also make use of multiple outputs to view on my usual monitor via RGB and record via composite.
I can then record the session to the PC, and go back through the recording to select the section I want and take screenshots.
Like the DVD option, this is particularly useful when I am trying to catch a particular event happening, or get some gameplay pictures rather which is difficult whilst holding a camera.
This device claims to support NTSC, but I didn't have any luck with an NTSC VIC20 (and yes, I did try NTSC and 'auto' and various other options, but it wouldn't lock on sync or show any colour).
(and yes, it is NTSC according to my LCD monitor).
It also had issues locking onto the Commodore PET (which is NTSC timing without a colour burst).
The PAL version was OK on the VIC20, and seemed to be a bit sharper than the DVD Recorder recording.
The C64 default blue on blue was a bit blurry.
These is an S-Video input. I tried connecting that up to the C64 instead.
The result was a bit better, less banding, still not brilliant, but better than the photos.
So, I have a couple of options for PAL systems. They're not great quality, and they don't support NTSC. Over to you, dear reader, can you suggest any methods that may work for me, or equipment I could try?

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