Recording video with Macintosh Classic II in frame

[m_emelchenkov]

Hello!

I'd like to record a video with Macintosh Classic II in frame. Unfortunately, I have a problem with synchronising refresh rates of iPhone SE and Macintosh Classic II display. If the information I found is correct, refresh rate of the display is 60.15 Hz. I tried to write a program which records video and uses AVCaptureDevice.setExposureModeCustomWithDuration(), AVCaptureDevice.captureDevice.activeVideoMinFrameDuration/activeVideoMaxFrameDuration. It seems, iPhone SE camera could record only with integer frame rates like 60 FPS or 61 FPS, no way to set 60.15 FPS, so I always see a moving vertical line due to out-of-sync problem. Any solutions? I thinking about post-production, but don't really want to look into this way, if there is any chance to record correctly synced video with iPhone.

 

[Gorgonops]

If possible you could try using a *longer* exposure time, maybe? You might have to play some serious games with lighting the scene to pull it off, though.

 

[m_emelchenkov]

If I understand the whole theory right, I need _exact_ the same frame rate as monitor refresh rate. Increasing or decreasing frame rate from this value will only make the problem bigger. Anyway, I played with different frame rates, 60 fps (and 30) is the only rates for the best result I can achieve.

Also, anyway, I can't set really large exposure because I record video, not still photos.

 

[just.in.time]

What about screen recording software on the Classic II? Idk if System 6 would have anything, but I wouldn't be surprised if there was something for System 7. Should be able to record to a .mov file.

Maybe Flash It or Gif.gif.gif from this page could help? Both say 680x0 support:

http://www.pure-mac.com/screen.html#gifgif

 

[m_emelchenkov]

@just.in.time, thanks, but I do not want to record the screen itself, but a video of a real hardware where the screen will be also readable.

 

[just.in.time]

Ah, got it. Yeah that might be a problem.

 

[Gorgonops]

My thought was that if you dialed it the frame rate down to 30 or 24 with a long shutter speed you'd get at least two passes of the electron beam on each frame which might even out the "flare" of the line currently being refreshed (which is what of course causes the moving line), but googling up some discussions on various forums suggest the improvement from that strategy isn't enough to write home about. A slow shutter does definitely help with still photography, but I guess 1/30th of a second isn't slow enough.

 

[Cory5412]

The iPhone 5S with the built in camera app only lets you choose 720p30 or 1080p30. If possible, I recommend choosing a p24 frame rate. It will probably look weird, that being a more "cinematic" frame rate, but it should mask the flicker.

This is the type of thing that a dedicated camera, either a DSLR/mirrorless or high end point and shoot that can do video, or a real video camera (they still make those? (yes they do)) may be best, especially something mid to high range.

You won't ever properly be able to sync it -- that's a capability that was available on ultra high end computer systems meant specifically for TV production and graphics, in particular Silicon Graphics, but I'm sure there were others and perhaps nubus/pci/agp/pcie cards for Macs.

I'm almost tempted to say to try recording in a slow-mo mode, and then re-time it back up to whatever frame rate your video project is, in your editor. Depending on what you're doing, this may or may not be viable if you're looking to record audio as well. You would need a separate audio recorder, whether that's another phone or a dedicated audio recording device, or if you use slow-mo on a dedicated camera, your iPhone for audio, then combine them in your favorite video editing software.

 

[just.in.time]

The 5s also supports 120fps slo-mo video recording at 720p.

 

[m_emelchenkov]

iPhone 5S != iPhone SE.

Based on my knowledge, the only allowed FPS is 60.15 Hz to get a whole picture from CRT screen. Please share your experience if you have success with another frame rates, exposure times and so on. Indeed, I can set, say 30 fps, but I need to set 1/60.15 exposure, and it don't work too, it rounds up to 1/60.

 

[m_emelchenkov]

You are right about experience with external sync video devices. I do not have such devices. Theoretically, so powerful device like iPhone SE should allow it with no problems, but it is not a pro-equipment so it is somehow limited in software or hardware, as we can see.

 

[Scott Baret]

Consider the target audience of the iPhone's camera. It is designed for users who want to create a home movie easily. They aren't too concerned about settings like that in general and just want something they can hold down a button on and shoot film with.

Higher end equipment is likely the only way to go here. The 5S may seem fancy compared to something older, but there are reasons why traditional cameras and camcorders haven't died out yet, not to mention why pros don't generally use phones.

 

[techknight]

I think the exact refresh rate is 59.97Hz.