47Tuc

[ZeroID]

Experimental imaging using C80A filter as LP control.
SONY DSLR, Lunt 102 f7 ED, ISO 1600, 30 seconds single frame unguided. RAW coverted to TIF then processed, levels, contrast, brightness and minimal sharpening. Then reduced for IIS posting. The image is uncropped.
The C80A leaves an overall blue tint to the whole image easily removed in Levels.
I wanted to have a go at Trifid for colours but the moon was not very cooperative (~45%). I shot a few frames of it and some colour seemed apparent.

[cometcatcher]

Interesting. An 80A blue filter in moonlight is probably not a good idea. Instead of LP washing out the image the Moon will. Blue will also put your optics to the test and make CA more noticeable. However if all that is less than heavy sodium orange glow, it may be worthwhile.

Did you do a shot without the filter for comparison?

[ZeroID]

Hi Kevin (again) Not this time. There is an example in the EPs and Filters thread first posting which is why I pursued this line. I figured it was stopping the Sodium glow and I was now more interested in seeing how it affected exposure, colours and processing requirements.
This is through the Lunt 102 f7 ED and I'm happy with the CA so far, it seems manageable. I may try the 80 f11.3 Achro later just for comparison.
When I get the ZWO operational for DSO I'll also be trying that with a similar filter. I have a 1.25" non CCD Astronomik CLS filter to compare it with. I actually found combatting the blue effect of that harder but that was a while ago and my resources and skills have moved on a bit since then.
2" filters are expensinve $$$$ ! This is what led to these trials in the first place.