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8mm film scanner / How many pictures possible per ten seconds?

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Re: USB remote and focusing just once
« Reply #40 on: 23 / November / 2015, 01:16:03 »
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Hi all,

The exposure should remain quite constant, as indeed the focus. I would rather not run a script, since the Arduino manages the film transfer and I can mechanically read the proper moment to trigger the camera.

The picture shows the trigger switch open. As I can rotate the servo at any speed (currently 2 sec / revolution), I can later experiment with the top speed for scanning. Currently it's just about getting the thing to focus once and keep it for the remaining session.

I will now try the AF lock from the camera menu and then see if it helps.

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Offline reyalp

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Re: USB remote and focusing just once
« Reply #41 on: 23 / November / 2015, 02:30:12 »
The exposure should remain quite constant, as indeed the focus. I would rather not run a script, since the Arduino manages the film transfer and I can mechanically read the proper moment to trigger the camera.
FWIW, you can use a script to sense the usb signal from the Arduino, using http://chdk.wikia.com/wiki/USB_Remote_V2#get_usb_power or wait_click/is_key remote

AF lock by itself will not lock exposure. You can may be able to use set_aelock (or the equivalent key presses), but this might break the normal USB remote shooting function.

Here's a simple lua example of a script that holds half press and clicks full every time there is a remote pulse:
Code: [Select]
press('shoot_half')
repeat sleep(10) until get_shooting()

repeat
 wait_click(10)
 if is_key('remote') then
  click('shoot_full_only')
 end
until is_key('menu')
release('shoot_half')
Don't forget what the H stands for.

Re: USB remote and focusing just once
« Reply #42 on: 23 / November / 2015, 02:59:37 »
Thanks, Reyalp! I will be sure to test this soon.

Should I install this as an autorun script, and can I still do a half-press manually to confirm the focus?

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Offline reyalp

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Re: USB remote and focusing just once
« Reply #43 on: 23 / November / 2015, 03:26:09 »
Should I install this as an autorun script, and can I still do a half-press manually to confirm the focus?
I just intended this as a quick example of the basic idea. Autorun is up to you, I don't know what your exact needs are. You might need to add other setup steps to the script, for example to switch to record mode.

If you want to verify focus manually, you would need to do that before running the script and set AF lock, otherwise the camera will attempt to focus on the first half press. If focus overrides work on your camera, you might just be able to set one focus distance in the script.
Don't forget what the H stands for.


Re: USB remote and focusing just once
« Reply #44 on: 25 / November / 2015, 07:02:25 »
I must be daft - I just don't get this.

What I would love to have is this:

1) I get the film system properly aligned and do a half-press to lock the focus.
2) I would want this focus to stay put until I turn the camera off.
3) While the focus is locked, I use the USB remote via Arduino to grab the pictures.

I have it almost nailed, but getting the timing perfect is hard when the camera autofocuses every time it has been shot. I have turned on the AF lock before loading CHDK, then ran the scipt Reyalp kindly provided, but it still does an autofocus every time it takes a pic.

What is it I am missing here? I also don't think I got my camera focused and zoomed to the max 4.0 via a script - it would help if that were possible, but my scripts don't cut it.

I am sorry to be wailing for help all the time, but I am so close to perfection....thanks :)

Re: USB remote and focusing just once
« Reply #45 on: 25 / November / 2015, 07:52:02 »
I have turned on the AF lock before loading CHDK, then ran the scipt Reyalp kindly provided, but it still does an autofocus every time it takes a pic.
Do you see the letters AFL on your camera's LCD when you do this?  If so, do they stay on for the whole shooting sequence or drop off?

When you mention "loading CHDK" does that mean using the firmware update method to load CHDK or does it mean CHDK is already loaded and you are just pressing the <ALT> key so that you can start the script?


Edit : attached is an update to reyalp's script.  Each time you press the  "Func/Set" button on the camera while the script is running the camera will refocus and then lock that focus for as long as the script stays running.  Toogle the USB remote state to shoot.  Press the "Menu" key to exit the script..
« Last Edit: 27 / November / 2015, 11:47:03 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16

Re: USB remote and focusing just once
« Reply #46 on: 25 / November / 2015, 07:54:47 »
I have to check for the AFL letters tomorrow, the scanner is being built at our 3D lab at the University.

I used the ALT key, then loaded the script from the list.

Re: USB remote and focusing just once
« Reply #47 on: 25 / November / 2015, 08:50:55 »
I have to check for the AFL letters tomorrow, the scanner is being built at our 3D lab at the University.
Good - it will be interesting to hear what you see.

Are you able to try the script I posted?  I've tested on one of my cameras and it seems to do exactly what you want.

Ported :   A1200    SD940   G10    Powershot N    G16


Re: USB remote and focusing just once
« Reply #48 on: 25 / November / 2015, 11:24:05 »
I did try the script today, but I didn't notice any change in the behavior of the camera, it did autofocus just the same. I wonder if I am doing it properly.

Re: USB remote and focusing just once
« Reply #49 on: 25 / November / 2015, 11:55:23 »
I did try the script today, but I didn't notice any change in the behavior of the camera, it did autofocus just the same. I wonder if I am doing it properly.
I'm not sure how you could have tried the script I posted as the download count indicates zero downloads?  :-[

With the script I posted (not reyalp's snippet),  the AFL symbol comes on the LCD as soon as I start the script.

I've attached a slightly modified version of the script here.  The new version does not set the AFL on startup - you have to press the "Func/Set" button.

So when I run this script and toggle the USB remote to make it shoot,  I can see & hear it focussing on each shot.  As soon as I press the "Func/Set" button,  it no longer adjusts the focus at each shot.

I have CHDK setup to display the SD (subject distance) and I can confirm that the distance selected stays "locked"  even if I point the camera somewhere much further away for the next shot.

This works on a couple different camera models I own.  So if this does not work for you then I suspect there is something strange about the CHDK port for your camera. Are you still using a ten year old Ixus 55 ?


« Last Edit: 25 / November / 2015, 11:57:58 by waterwingz »
Ported :   A1200    SD940   G10    Powershot N    G16

 

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