I'm looking at getting one of these for the modded 300D since it is too red so i can custom white balance properly each time. Are these any good? has anyone tried this?
arh thanks paul for the link. I was wondering, since it is modded, red channel will be enhanced thus when taking astro images, it will turn out overly red unless you process the crap out of it. Normally, you put a piece of white paper under sunlight, take a shot using standard lense, then use that pic to set it as CWB. I have been doing that which makes it a huge difference. The white balance lense cap will be more constant and accurate.
It is meaningless to compensate for white balance with astro images. Signal is signal and how you put it together for a final image is almost purely what you think the object looks like from the last image you think you saw.
The filter in front of the sensor of modern digital cameras tries to modulate the sensors spectral sensitivity to match the human eye sensitivity. The further complicating factor is the ambient illumination which can shift colour balance. Our eyes do this automatically!
This is what colour balance attempts to do.
Removing the filter to 'modd' the camera makes it far more sensitive in the far red to pick up HA which we can barely perceive. So if you then balance again you lose HA sensitivity so defeating the reason for removing the filter in the first place.
If you worry that your red histogram is way higher than green or blue just do what I do, ignore it!
Setting the colour temperature to 4000K when converting from RAW to TIFF will compensate without losing data in the red channel!
I thought by just removing the stock IR filter, that already in itself improves HA emission. how would balancing colours using CWB decreases this? *shrugs, i just dont' get it*.
I haven't notice any difference using the modded 300d in AWB and CWB, only thing is that CWB i think personally, is better balance in colours and less processing involved.
I always use CWB for my astro shots..Like you mention it makes it much easier to get your color balance close and in processing..I find it gives me a more pleasing image color wise..but that has alot to do with personal taste as well..
when I first modded the camera I did some experiments with AWB and CWB and CWB won out for me.. I couldn`t see any difference in Ha sensitivity only differences in color balance..
cheers
hey gary, your M20 Triffid image.... that is a fine example what i called correct colour balancing. is it possible to post your CWB image so i can get a fair idea what i should be aiming for?
hey gary, your M20 Triffid image.... that is a fine example what i called correct colour balancing. is it possible to post your CWB image so i can get a fair idea what i should be aiming for?
cheers
No probs Eric! I have it somewhere on this pc as I remember keeping it...
I shall post when I find it .
cheers