Filter Wheel Convention...

[fatwoul]

I was talking to Martin about this at the fair yesterday. I was asking him if there is a recognised convention to the order filters are put in a filter wheel. He said he thought not, and I'm sure he's right, but he mentioned his own order and it differs from mine.

My EFW2 is a 9-hole 1.25, and goes C, HA,HB,OIII, SII,L,R,G,B. I put C in hole #1 so it is the default filter in place for focusing, the narrowbands next because my location means they get used more often, followed by luminance and then finishing with the RGBs.

I know it doesn't matter in the slightest, but the reasoning I used, and Martin used, interested me. So, I wondered what everyone else does.

[steppenwolf]

L R G B Ha OIII SII Hb for me but that's just me, it seemed logical at the time

[ncjunk]

LRGBHa for me, i normally image using R first then G and B for when stuff is higher up. So I keep it in the order i am likely to use it.

If I do Ha it tends to be using just that filter and a single target.

Having said all that i have noticed the R is in the first slot...should have put the L there for focusing...oh well.

[fatwoul]

Yeah mine started with the L at first, but I decided C might as well be the first since that's what its for. Else I'd never use it at all!

[Whippy]

FWIW, I has mine setup as RBG purely because if you didn't get round to getting any Green one session for some reason, I could at least get an idea of the image by processing the Red and Blue, then creating a false Green channel using Noel's action in Photoshop. That way you've still got an image to play with and you could get the Green next session.

Tony..

[roundycat]

SBIG filter wheels are usually marked but the order is unimportant. You just need to know the wheel and its s/w are singing from the same hymn sheet.

Dennis

[fatwoul]

FWIW, I has mine setup as RBG purely because if you didn't get round to getting any Green one session for some reason, I could at least get an idea of the image by processing the Red and Blue, then creating a false Green channel using Noel's action in Photoshop. That way you've still got an image to play with and you could get the Green next session.

That's a really good tip, Tony. In fact, that very thing happened to me at the weekend. I got R and G sets for M51 but no blue. Had I got RBG I could have done just as you describe.

SBIG filter wheels are usually marked but the order is unimportant. You just need to know the wheel and its s/w are singing from the same hymn sheet...

I know, Dennis. This thread is really a bit if a silly one. It just got me thinking about the order and why I chose it, and why other people might choose theirs.

Interesting that SBIG do have some kind of convention, though. Does that correspond to some software used with their FWs or something?

[roundycat]

Can't answer that. I believe the relevant SBIG s/w is CCD Ops which I never use being a MaxIm man. Setting any order you want in MaxIm is as easy as falling off a log and then you can change it again in the auto exposure sequence.

Dennis