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Get focused distance

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Get focused distance
« on: 22 / January / 2008, 04:47:44 »
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Hello,

I have a G7 camera but I'm new to CHDK.

Is it possible to get the distance from the subject (focused distance) after an Auto Focus? (Using the camera as a distance meter.)

How about doing this remotely? I'm using my own program written with the Canon PR-SDK for controlling the camera and making the shots. I want to know the focused distance after doing an Auto Focus remotely. Also I want to have the exact distance after making the shot to calculate the real size of the subject in the photo. (the maximum distance that I need is about 1 meter). Is it possible with the help of CHDK? Is it possible to communicate remotely with CHDK?

Would you please help me on this topic(Metering the distance)? Where should I start from?

Regards,
Parham.
« Last Edit: 22 / January / 2008, 05:48:22 by Parham »

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Offline GrAnd

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Re: Get focused distance
« Reply #1 on: 22 / January / 2008, 15:21:29 »
Firstly, the metering of distance is not accurate. You can see the distance on the LCD, if you are using the CHDK.
Secondly, the CHDK is not able (yet?) to communicate through USB.
And the last. Why do not use a distance from the EXIF info stored in the picture?
CHDK Developer.

Re: Get focused distance
« Reply #2 on: 22 / January / 2008, 23:40:54 »
I have installed Allbest's build on my G7. But I cant find the distance as mentioned in the wiki. Where is the distance? I can not find any option to show "F"? Is "S" the distance in the Allbest's build?

Distance from EXIF? I want the distance before making the shot and after each AF. Also the FocusDisstanceUpper in the EXIF its not relevant to the real distance in distances over 50cm!

Is it possible to make some improvement and calibration on the distance?

When connecting remotely to the camera, is CHDK still running? We can make it save the distance to a file and then read the file in the PC!? Is it possible to draw the distance on the live image that we receive remotely?! or store the distance in the live image data stream and the extract it from the stream on the PC?! (Everything is possible!  :D)

Best Regards,
Parham.
« Last Edit: 22 / January / 2008, 23:53:30 by Parham »

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Offline GrAnd

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Re: Get focused distance
« Reply #3 on: 23 / January / 2008, 07:35:02 »
Distance from EXIF? I want the distance before making the shot and after each AF. Also the FocusDisstanceUpper in the EXIF its not relevant to the real distance in distances over 50cm!
CHDK uses the same distance for displaying on LCD.

CHDK Developer.


Re: Get focused distance
« Reply #4 on: 23 / January / 2008, 08:41:10 »
Hi GrAnd,
Thank you for the reply.

What about my other questions?

1- When connecting remotely (via PR-SDK) to the camera, is CHDK still running?

2- (If 1 is true) Is it possible to pass some data with the data that the PR-SDK is reading from camera (e.g. with the live image stream)?

3- (If 1 is true and 2 is false!) Is it possible to store the distance in a file on the SD card after each Auto Focus?

Regards,
Parham.

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Offline GrAnd

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Re: Get focused distance
« Reply #5 on: 23 / January / 2008, 08:50:26 »
1) If it's running when camera was switched on it will be still running.
2) It's too difficult.
3) Yes. But it will be the same distance as in the EXIF data.
CHDK Developer.

Re: Get focused distance
« Reply #6 on: 23 / January / 2008, 08:57:54 »
Quote
3- Is it possible to store the distance in a file on the SD card after each Auto Focus?

Quote
3) Yes. But it will be the same distance as in the EXIF data.

Ok, I will do some calibration on the distance. But where should I add the code for saving the file on the SD? Would you please provide a sample code?

Regards,
Parham.

Re: Get focused distance
« Reply #7 on: 24 / January / 2008, 01:02:50 »
Deleted
« Last Edit: 22 / April / 2008, 09:53:26 by Barney Fife »
[acseven/admin commented out: please refrain from more direct offensive language to any user. FW complaints to me] I felt it imperative to withdraw my TOTAL participation. Nobody has my permission, nor the right, to reinstate MY posts. Make-do with my quoted text in others' replies only. Bye


Re: Get focused distance
« Reply #8 on: 24 / January / 2008, 01:14:57 »

Maybe use the "print_screen" and "get_focus" commands and ask your question in the Script Writing forum?


Should I go for Script Writing or modifying the CHDK? Is it possible to have Auto Focus event or saving a file in Scripts?

 

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