7 or 8 position filter wheel advice

[Haggis]

Dear SGL folks,

I own an ATIK 11000 CCD camera and a EFW2 filterwheel. I bought this setup used and it came with a nice set of Baader 50.4mm filters (L,R,G,B,Ha and OIII). I'm still looking into buying a SII filter and maybe a Hb filter. Unfortunately, I can't mount all the filters at once so if I want to change from RGB to narrowband imaging, I have to remove the filterwheel, open it up and replace the filters all the while risking dust to fall on them.

I was thinking, I could buy a second EFW2 filterwheel, an extra Ha filter and leave the original filterwheel in a LRGBHa setup and the second wheel with the OIII, Ha, SII and maybe Hb. Replacing the filterwheel is only a matter of seconds and it's a lot faster and safer than changing filters inside the wheel.

However, I prefer a good filterwheel with 7 or 8 positions but I can't find anything online that fits my ATIK 11000. Maybe I didn't look hard enough but is there a 7 or 8 position filterwheel that matches the ATIK 11000? Preferably at an affordable price of course. And of course I could also just man up and change filters everytime like everbody else does but mmmmm, I would really like a bigger filterwheel!

[Waldemar]

Did you see this one?: http://www.optcorp.com/fli-cfw-2-7-seven-position-color-filter-wheel-50mm-filters.html

[Haggis]

Hey thanks! Those 7 position filter wheels don't come cheap but now at least I know it's possible. Will Atik Artemis (capture software) work with different brand filterwheels I wonder?

More alternatives are welcome of course! If anyone has a nice 7 position wheel for sale I would also like to know. Or a used EFW2 wheel is also a possibility. I live in the Netherlands.

[carastro]

I saw Bern at Modern astronomy selling a 7 position 2" filterwheel once, you'd need to check whether your filters and threads will fit though.  I don't think the price was anything like the one linked.    

I am using an AtikEF2 with 7 positions 35mm unmounted filters if you decided to sell what you have and buy this instead.

Carole

[Haggis]

Thanks! I now use Baader 50.4mm unmounted round filters. Am I right that 2 inch is the same as 50.8mm? Will a 50.4mm filter fit inside a 50.8mm slot? I just checked the Modern Astronomy website but I don't see a 7 position 2 inch filterwheel so I suppose he sold it.

[Waldemar]

Normally when 2" is mentioned people mean 2" mounted filters a.f.a.i.k., which is M48 x .75 . But even if they would fit, there will be threaded slots, you need a slot with nylon screw clamps for your unmounted filters. 

QHY has a 7 position wheel as well: www.QHYCCD.com 

Waldemar

[Haggis]

Thanks for the explanation. I'm new to CCD imaging so filter sizes is a bit confusing. It looks like the QHY 7 position filter wheel uses square filters. That means I would have to sell my 50.4mm filterset first, then buy square filters again. Hmm... I think the FLI filterwheel is still the best option so far. Or just buying a second EFW2.

[Owmuchonomy]

May be a dumb question but is impossible to get through 7 filters in one session?  I have been researching a new set up for imaging and I am considering a 5 position wheel as more than enough for one imaging session.

[ChrisLX200]

I have a Moravian 7-pos filterwheel, my version uses 50mm square filters but there are also others that use 50mm round etc. Be aware these wheels are big and quite heavy when loaded with glass filters.

ChrisH

[Haggis]

Hi Owmuchonomy. Of course most of the time 5 filters are enough for one single session, but sometimes the moon's up and I like to do narrowband nebula shots and sometimes it's clear and I like to do galaxy LRGB shots and in between we have lots of rain without planning ahead which filters I'm going to use. Of course I could swap the filters right before each session but it's also nice to have everything in one filterwheel. Besides, messing around with filters can cause damage and there's a big chance to collect dust and fingerprints. Also, with the filters in the same place all the time I have a higher chance of succes with using the same flats frames I took earlier. So it's not a very big deal but if there's a nice new thingy to buy for my telescope I would really like a bigger filterwheel :-)

@ChrisLX200, I thought Moravian filterwheels were always connected to Moravian cameras. I didn't know you could buy them seperately. Interesting, I'll take a look at their website and see if they have one that fits my Atik 11000. My focuser is a strong JMI 3 inch and the OTA is made of carbon fibre so it should be able to carry the weight. That's what I bought it for.

[ChrisLX200]

@ChrisLX200, I thought Moravian filterwheels were always connected to Moravian cameras. I didn't know you could buy them seperately. Interesting, I'll take a look at their website and see if they have one that fits my Atik 11000. My focuser is a strong JMI 3 inch and the OTA is made of carbon fibre so it should be able to carry the weight. That's what I bought it for.

That might be the case! Not sure if they work with other cameras, but just wanted to point out the weight is significant for these big wheels.

ChrisH