OK - I decided to take my Toucam modification 2 steps further. One of the problems with the standard SC3 modification is that during long exposures the frame suffers from excess glow in the top left hand corner due to an on-board amplifier. It's not a problem for exposures up to about 15 secs but over that it starts to white out the image. I decided to do an Amp Off mod (although I was a bit apprehensive as it meant taking my camera to bits again & risking messing it up). Anyway I did the mod today & at the same time added 'forced air cooling' via a 12V fan. You can see the results below.
The three images each represent a stack of 10 X 60 sec expsoures at maximum gain. I have not stretched these images I have just stacked the individual exposures (as though I was creating a dark frame in Registax). The first image is my SC3 with the Amp turned on & no cooling (i.e. how it was before I modded it) The second is with the Ampoff mod installed & the third is the Ampoff mod & cooling..
I think the results speak for themselves - I'm very pleased.... :-) Can't wait to give it a try out...
Cheers, John.
PS - Additional components cost about £7
Ampon - 10 X 60 secs
(http://homepage.ntlworld.com/john.punnett/graphics/oas/Dark_ampon_10X60_A.jpg)
Ampoff - 10 X 60 secs
(http://homepage.ntlworld.com/john.punnett/graphics/oas/Dark_ampoff_10X60_A.jpg)
Ampoff + cooling - 10 X 60 secs
(http://homepage.ntlworld.com/john.punnett/graphics/oas/Dark_ampoff_10X60_cooled_A.jpg)
Wow! Big difference to that dark frame!
There seems to be two sources of glow, one that disappears with the amp off. What is the second one John ?
Hi Mike,
They are both part of the same problem - It's just the mod doesn't totally eliminate it. There are other mods that use different circuits etc. but they are a lot trickier to implement. The improvement I got by doing the basic is sufficient for the exposures/ setup I have at the moment.
Cheers, John
I can't beleive the difference, it was interesting.
Fay