G Series TTL In Manual Mode

MrSim17

27

G Series TTL In Manual Mode

« on: 02 / December / 2010, 15:46:53 »

Advertisements

I've done some searching in the forum and haven't seen any mention of this. Is it possible to use CHDK to turn on TTL flash exposure compensation while in manual mode in the G series cameras? The G series cameras offer TTL in all of the other modes such as shutter and apeture priority modes. Canon, however, purposely disabled TTL in Manual mode.

Has anyone else wondered about this feature?

Logged

jamesinsummer

2

Re: G Series TTL In Manual Mode

« Reply #1 on: 06 / January / 2011, 12:16:17 »

I just made a one for G9 yesterday.
Let me know if you need it.

James

Logged

MrSim17

27

Re: G Series TTL In Manual Mode

« Reply #2 on: 07 / January / 2011, 10:40:16 »

James,
THat woudl be great! I'm still waiting for the port to the G12 but It'll be nice to have when I have some time to start looking into G12 ports. I'd appreciate any information on what sorts of changes you had to make.

Thanks James!

Logged

MrSim17

27

Re: G Series TTL In Manual Mode

« Reply #3 on: 28 / February / 2011, 10:13:34 »

James,
I have finally had some time to get the new beta of CHDK going on my G12. Could you please post some information about your TTL in manual mode implementation? That is my #1 feature I'd like to get going on CHDK.

Thanks,
Nathan

Logged

jamesinsummer

2

Re: G Series TTL In Manual Mode

« Reply #4 on: 09 / March / 2011, 16:25:32 »

Nathan,

Sorry, I did not check the forum recently.

Not sure if you still need G9 script, since you got G12.
But below is the script, I found it on my flash driver, it should work.
=================================================

@title Flash TTL
@param a Flash :0 TTL,1 Manul power (0,1)
@default a 0
@param c Flash compensation (-3~3)
@default c 0

rem DIGIC3 Flash Power id:121 0:auto 1:Manual
rem the default setting
get_prop 121 q
print "Default TTL: ", q
set_prop 121 a
get_prop 121 q
if q=0 then print "Flash in TTL mode"
if q=1 then print "Flash in Manual mode"

sleep 500

e=0
set_prop 127 e
get_prop 127 P
c=c*96
print "Old compensation:",P
P=P+c
set_prop 127 P
print "New compensation:",P

end

==========================================

James

Logged

MrSim17

27

Re: G Series TTL In Manual Mode

« Reply #5 on: 09 / March / 2011, 16:47:28 »

Thanks a lot James! I checked out the v4 properties. Looks like 121 is implemented for G12 but not 127 as far as I can tell. I'm going to play around with it some tonight if I have time. Thanks a lot for the script and pointing me in the right direction!

Nathan

Logged

jurgenfd

14

Re: G Series TTL In Manual Mode

« Reply #6 on: 13 / June / 2011, 17:11:12 »

Hi James,

I'm new to this CHDK thingy and before I try to delve into it. Could you tell me if the script you show would be applicable to the S95? Any mods needed?

This feature would be -very- useful for my application in underwater photography where changing the external slave strobe output settings is hard to do with thick gloves here in the cold waters of the Netherlands.

Thank you so much,
Jurgen

Logged

MrSim17

27

Re: G Series TTL In Manual Mode

« Reply #7 on: 14 / June / 2011, 10:38:33 »

Jurgen,
I think that the script should look. I'm betting that the DIGIC version in the s95 is probably the same or similar to the one in the G12. The script modifies specific properties in the processor to turn on TTL. I've got a refined script that I can post later that simply toggles TTL mode. So that way when you get in the water you just tur on the camera and run the script once and it toggles between TTL flash mode and manual flash mode. Worked great for me on my last dive trip. The TTL GREATLY improved the quality of my images. Unfortunately the exposer compensation settings via the scripts did not work. I'm not sure why or if that will be the same in the S95. But if you shoot in raw really you can just adjust the exposure with photoshop. Not the most ideal solution but it works.

Nathan

Logged

jurgenfd

14

Re: G Series TTL In Manual Mode

« Reply #8 on: 26 / June / 2011, 17:36:05 »

Thanks guys. This is a wonderful feature for me!

I haven't tried to work out the exposure compensation but did a rehash of the code by jamesinsummer to make it even more dummy proof (I need that

).

Code: [Select]

@title TTL flash
rem Author: Jurgen F. Doreleijers

rem Toggle between TTL and manual flash. This is useful for e.g. underwater photograpy with Canon S95
rem with mode dial in 'Manual' for which the factory firmware doesn't support TTL.

rem Script is based on the example of jamesinsummer from:
rem [url=http://chdk.setepontos.com/index.php?topic=5876.msg68670]G Series TTL In Manual Mode[/url] 

rem a=alternate (swapped from before)
rem b=before
rem c=current

get_prop 121 b

rem Reporting to user with strings i.s.o. numbers
if b=0 then 
    a=1
    print "TTL to M"
else
    a=0
    print "M to TTL"
endif

set_prop 121 a
get_prop 121 c

rem print  "DEBUG: From", b, "to", c

rem Error reporting. Never observed the failure in testing.
if a<>c then print "ERROR: failed to (re)set"

Logged

jurgenfd

14

Re: G Series TTL In Manual Mode

« Reply #9 on: 30 / June / 2011, 16:14:07 »

Sorry to hijack this thread. Perhaps a small improvement to the above still. The below script can be set to autostart and set to TTL flash in any startup situation. It should only matter in the M mode.

Code: [Select]

@title auto TTL
rem Author: Jurgen F. Doreleijers

rem Turn on TTL flash if it was not on already. This is useful for e.g. underwater photography with Canon S95
rem with mode dial in 'Manual' for which the factory firmware doesn't support TTL.
rem The script can be set to auto run. No more worries.

rem Script is based on the example of jamesinsummer from:
rem [url=http://chdk.setepontos.com/index.php?topic=5876.msg68670]G Series TTL In Manual Mode[/url] 
rem DIGIC3 Flash Power id:121 0:auto 1:Manual

rem b=before
rem c=current

get_prop 121 b

rem Reporting to user with strings i.s.o. numbers
if b=0 then 
    print "Still TTL"
else
    set_prop 121 0
    print "Now TTL"
endif

get_prop 121 c

rem print "DEBUG: From", b, "to", c

rem Error reporting 
if c=1 then print "ERROR: failed to (re)set"

Logged