Powershot SX200IS - get_dof and get_dofinfo - DryOS Development - CHDK Forum

Powershot SX200IS - get_dof and get_dofinfo

• 5 Replies
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Nando

• 16
Powershot SX200IS - get_dof and get_dofinfo
« on: 15 / January / 2011, 11:48:42 »
« Last Edit: 15 / January / 2011, 11:53:09 by Nando »
Canon Powershot SX200 IS

reyalp

• 14098
Re: Powershot SX200IS - get_dof and get_dofinfo
« Reply #1 on: 15 / January / 2011, 15:25:04 »
You can find the C code for these functions here:
http://tools.assembla.com/chdk/browser/trunk/platform/generic/shooting.c
Don't forget what the H stands for.

Microfunguy

• 4037
Re: Powershot SX200IS - get_dof and get_dofinfo
« Reply #2 on: 16 / January / 2011, 05:59:30 »

@Nando

What is your graph with the vertical bars showing and can you explain the parameters used ?

Are they real values * 1000 ?

Please explain the formula you are using in greater detail.

« Last Edit: 16 / January / 2011, 06:30:52 by Microfunguy »

Nando

• 16
Re: Powershot SX200IS - get_dof and get_dofinfo
« Reply #3 on: 16 / January / 2011, 08:01:06 »
Hello,

@reyalp
thanks for the link, i take a look!
Let's see if I can find a starting point.

@Microfunguy
I try to explain.
DOF is growing with distance. So I use an exponential function to set the focus.
Redundant focus, I would like to leave out.

g=f+(d*(i^5)/(10^5)+i)*10*b

g = next focus
f = current focus
i (i=1 to a) = number off shoot
b = multiple of the step size
d = rise of function

I hope it is understandable.

bye,
Nando
Canon Powershot SX200 IS

Microfunguy

• 4037
Re: Powershot SX200IS - get_dof and get_dofinfo
« Reply #4 on: 16 / January / 2011, 09:23:33 »

DOF is growing with distance. So I use an exponential function to set the focus.
Redundant focus, I would like to leave out.

Yes, but  required focus-step depends on initial focus, aperture and focal length.

With SDM, this feature is built-in, you do not need a script.
In fact, I am testing a new version right now that tells you how far to move the camera to create stereo focus stacks,
(if you want to test it, contact me directly).

You can also log the focus positions.

See this post http://chdk.setepontos.com/index.php?topic=6014.msg59814#msg59814

Nando

• 16
Re: Powershot SX200IS - get_dof and get_dofinfo
« Reply #5 on: 18 / January / 2011, 04:57:16 »
Hi Microfunguy,
many thanks, i've tried it yesterday!

I have sent you a message.

bye,
Nando
« Last Edit: 18 / January / 2011, 06:03:36 by Nando »
Canon Powershot SX200 IS