I'm getting a filter wheel (ZWO) 7 2 inch filters. I need advice tks

[DSOBug]

Which filter do I need I'm getting a Asir533mc Pro camera which is color, also I'm thing on getting the Optolong L-Ultimate dual-3nm filter. But what others do I need with a Color Camera like the Asir533mc Pro.  Do I need LRGB Set  and the Hydrogen Alpha, Oxygen 3, Sulfur 2,   Where does the L- Ultimate go in the wheel?     If you add all the filters I listed with the Ultimate there's 8 filters. and Ideas tks

[DaveS]

With OSC there's no point in getting the LRGB / NB set, and I would argue, no need for a filter wheel, a simple filter drawer like the ones that ZWO do will do as well, cheaper, and avoid the need to balance a big off-centre wheel.

Although I don't use OSC I have considered it and would go with just a duo band filter for H-alpha and [OIII], and either a LP or IR / UV cut filter depending on your light pollution levels.

[teoria_del_big_bang]

I would agree with the above advice, no real need for a filter wheel with OSC as you are unlikely to be switching between lots of filters during as session like you need to with mono.

Also, if you did decide you still need a filter wheel do you really want to be forking out for 2" filters, decent 2" filters are expensive and I would think unnecessary for a 1" CMOS camera.

Steve

Edited October 26, 2023 by teoria_del_big_bang

[Elp]

As above. All the "narrowband OSC" Optolongs perform though people complain about star halos around bright stars, they get progressively more expensive as you go up the range, enhance/extreme/ultimate as their bandpass narrows. I settled on an extreme, but if I were to go for a replacement I'd get an Antlia ALPT Gold, costly as it is.

LP ones are generally a waste of time due to LED lighting casting across a broad spectrum, you'd be better with a UV/IR cut (or luminence) filter, they just reduce star bloat a bit due to IR, and address your LP gradients/glow in post processing, obviously also don't use it when the moon's out near full or close to your target (that's when you use the narrowband OSC one on emission nebulae).

Edited October 26, 2023 by Elp

[LaurenceT]

Not wishing to hijack the thread but possibly something that may be of interest to the OP.

I am a novice for information, I also have the 533mcPro camera. Should I choose to use different filters during an imaging session can these be integrated in software such as Siril or APP?

The reason that I might want to do this would be to eliminate star bloat in a certain refractor and also bring out nebulosity by using an Astronomik L3 and an L-Enhance in the same session.

If I'm talking out of my rear please put me right!

[Elp]

I find it easier doing such things in PS or GIMP.

[sinbad40]

Agree with most of the above about RGB (not needed for colour camera) etc, But i have a 533C camera, and i also got a filter wheel.  I only use 4 of the slots, L-pro, L-Enhanced, Ha/OIII and a SII/OIII.  I got a 2" wheel to future proof things for the next camera.  I do have a filter draw (started with it) that isn't used at the min, but will be on another telescope with just a LP filter for wide field.

My main reason to get it was if i was changing target and needed to change the filter, I didn't want to get up in the middle of the night to do it.

[Anne S]

I have a ASI533MC which I use with a uv/ir cut filter to stop the stars bloating and duo narrowband filters Ha/O3 and S2/O3. I started with a L'Enhance which also worked well, though I bought that to use with a colour ccd camera which was less sensitive. I started with a filter slide but quickly switched to a filterwheel I already had and bought it a 5*2 carousel. I felt the issue with the filter slide was doing flats as they would need redoing every time you switch filter. It's also easier with the filterwheel as I can run all filters when needed. The Uk tends to cloud over mid session! All the duoband filters I've seen are in 2 inch format, possibly because there are many large format cmos cameras.

As to balancing with a filterwheel, I just orientate it so it's opposite to the focuser as the motor also affects balance. I have seen a filterwheel balance kit which fits to ASI cameras which would solve that.

Recent result below using my 2 nb filters with the uv/ir cut one for RGB stars as the nb ones are very magenta.I'm really pleased with the nb filter performance, just 50 minutes for each filter with 30 minutes rgb stars.

 

[ollypenrice]

Let's think it through. An OSC camera has either a red, a green or a blue filter permanently fixed in front of every pixel. That is what makes it an OSC camera. 

If you put a red filter in front of this, only the camera's red-filtered pixels pixels will get any light. The same applies to the other colours. With a green filter in front, only the camera's green-filtered pixels will get any light. Clearly, therefore, RGB filters would be pointless.

What's a Luminance filter? It's one which passes R and G and B. But your camera's filters are only going to pass the colour they pass, so R or G or B. A luminance filter would, therefore be useless.

Basically, you are going to be imaging with the camera's in-built RGB or with the dual band filter which further restricts what you capture to the light emitted by two gasses. Some targets will be best unfiltered, some filtered and some combining filtered with unfiltered. The worse your light pollution, the more favourable the filter becomes.

Olly

[teoria_del_big_bang]

3 minutes ago, sinbad40 said:

Agree with most of the above about RGB (not needed for colour camera) etc, But i have a 533C camera, and i also got a filter wheel.  I only use 4 of the slots, L-pro, L-Enhanced, Ha/OIII and a SII/OIII.  I got a 2" wheel to future proof things for the next camera.  I do have a filter draw (started with it) that isn't used at the min, but will be on another telescope with just a LP filter for wide field.

My main reason to get it was if i was changing target and needed to change the filter, I didn't want to get up in the middle of the night to do it.

Makes sense I guess, never done any OSC but I guess with al the different filters now available for OSC I can see that to automate the process a filter wheel would be useful.

Steve

[The Lazy Astronomer]

5 minutes ago, ollypenrice said:

A luminance filter would, therefore be useless.

I have to say I disagree with this part of your post. I think a luminance filter still serves a purpose if (1) you're using a scope which doesn't have perfect colour correction (i.e. most non-premium refractors), and, (2) you choose one of the more restrictive lum filters, which cut the extreme ends of blue and red.

[Elp]

42 minutes ago, ollypenrice said:

A luminance filter would, therefore be useless.

Why is a UV/IR cut filter recommended (for cameras with all pass front glass), and the lum is useless? The lum also cuts UV/IR?

Edited October 26, 2023 by Elp

[DSOBug]

Thanks for the advice, I have a Redcat 51, AM5, 120mm G S. Asiair Plus, EAF,  I was going for the 1.25  5 place filter wheel but as someone said go for the 2" wheel to future proof, I think that's a good Idea.  Also I'm going for the Optolong 2" L-Ultimate Dual Bandpass Light Pollution Reduction Imaging Filter.  And adding Ha/OIII and a SII/OIII filters to the wheel also. 

Whats everyone's thoughts on that.

[gorann]

11 hours ago, sinbad40 said:

Agree with most of the above about RGB (not needed for colour camera) etc, But i have a 533C camera, and i also got a filter wheel.  I only use 4 of the slots, L-pro, L-Enhanced, Ha/OIII and a SII/OIII.  I got a 2" wheel to future proof things for the next camera.  I do have a filter draw (started with it) that isn't used at the min, but will be on another telescope with just a LP filter for wide field.

My main reason to get it was if i was changing target and needed to change the filter, I didn't want to get up in the middle of the night to do it.

 

11 hours ago, Anne S said:

I have a ASI533MC which I use with a uv/ir cut filter to stop the stars bloating and duo narrowband filters Ha/O3 and S2/O3. I started with a L'Enhance which also worked well, though I bought that to use with a colour ccd camera which was less sensitive. I started with a filter slide but quickly switched to a filterwheel I already had and bought it a 5*2 carousel. I felt the issue with the filter slide was doing flats as they would need redoing every time you switch filter. It's also easier with the filterwheel as I can run all filters when needed. The Uk tends to cloud over mid session! All the duoband filters I've seen are in 2 inch format, possibly because there are many large format cmos cameras.

As to balancing with a filterwheel, I just orientate it so it's opposite to the focuser as the motor also affects balance. I have seen a filterwheel balance kit which fits to ASI cameras which would solve that.

Recent result below using my 2 nb filters with the uv/ir cut one for RGB stars as the nb ones are very magenta.I'm really pleased with the nb filter performance, just 50 minutes for each filter with 30 minutes rgb stars.

 

 

I either use my OSCs (ASI2600MC) with IDAS NBZ(Ha+Oiii) or without filter (so RGB, the camera has a built in UV/IR cut). However, I am curious how you process the data if you use both Ha+Oiii and Sii+Oiii filters. Do you make separate images or mix them somehow, like putting the red channel from Sii+Oiii data into the green channel of the image?

[900SL]

I run a 533MC pro. No filter wheel.

I have a zwo slot filter holder and 3 loaded filter drawers, 2 x narrowband and 1 x uv/ir (L2)

Antlia ALP-T is a better NB filter than the Optolong

[900SL]

29 minutes ago, gorann said:

 

I either use my OSCs (ASI2600MC) with IDAS NBZ(Ha+Oiii) or without filter (so RGB, the camera has a built in UV/IR cut). However, I am curious how you process the data if you use both Ha+Oiii and Sii+Oiii filters. Do you make separate images or mix them somehow, like putting the red channel from Sii+Oiii data into the green channel of the image?

You can split the colour channels in Siril then recombine them in varying proportions and colour mapping in Siril pixel math

[sinbad40]

I create 2 different images, one from the Ha/O3 and one from S2/O3, then split the channels of each RGB, then you can blend them.  Plenty of material/videos on sho / hoo etc.

[Anne S]

47 minutes ago, gorann said:

 

I either use my OSCs (ASI2600MC) with IDAS NBZ(Ha+Oiii) or without filter (so RGB, the camera has a built in UV/IR cut). However, I am curious how you process the data if you use both Ha+Oiii and Sii+Oiii filters. Do you make separate images or mix them somehow, like putting the red channel from Sii+Oiii data into the green channel of the image?

My ASI533 only has an ar filter. I prefer to have a separate uv/ir cut filter which is parfocal with the ultranarrowband filters. All are 1.8mm thick. I can then focus with the uv/ir cut filter which is quicker. I'm imaging with a f7 scope with a 0.8 focal reducer so the focus range is reasonably wide.

[teoria_del_big_bang]

5 hours ago, DSOBug said:

Thanks for the advice, I have a Redcat 51, AM5, 120mm G S. Asiair Plus, EAF,  I was going for the 1.25  5 place filter wheel but as someone said go for the 2" wheel to future proof, I think that's a good Idea.  Also I'm going for the Optolong 2" L-Ultimate Dual Bandpass Light Pollution Reduction Imaging Filter.  And adding Ha/OIII and a SII/OIII filters to the wheel also. 

Whats everyone's thoughts on that.

In short if you can afford then yes its a good idea, probably only downside is you are adding  a lot of extra weight to your set-up.

If you are definitely in this hobby for the long term and you can afford then probably a good idea. I think everybody would go this route apart from the expense of the 2" filters.
I can only speak for myself but I have 36mm unmounted and with my set-up this is probably the smallest I could get away with but I had the choice to either get what are considered some of the best filters (more on the NB side not so much LRGB) which at the time was Chroma or Astrodon, eye-wateringly expensive but I had such bad issue with halos on OIII filters in the past so wanted something that worked well. Of course I would have liked 2" but no way I could afford all 3 Ha, SII and OIII and to keep then as close to parfocal as possible I wanted all 3 to be the same manufacturer, so discarded the thought of buying an Astrodon  or Chroma OIII and cheaper Ha and SII. Hence my 36mm choice. 

Your case using OSC is a bit different of course as you will not need the same number of filters despite them still being expensive. However, will you stick with OSC ???  
What is LP like where you intend to image ?  There has been tremendous improvements with dual-pass filters, and also OSC CMOS cameras, so maybe LP not such an issue these days but maybe you do decide to buy a mono camera next time then you will be changing all your filters at a tremendous cost - maybe a consideration only you know 🙂 

Steve

Edited October 27, 2023 by teoria_del_big_bang

[teoria_del_big_bang]

Another possible consideration might be can you fit a 2" FW in your back-focus.
I have not looked into it but I imagine these heavier bigger FW's will have bolt on adapters that tend to take up more of that back focus, probably not an issue unless you decide at some point to get an electric rotator and need to fit that in the imaging train. I have one and love it, it makes framing so much easier but I bought what is probably one of the thinnest filter wheels going and still struggled getting a rotator to fit in my BF.

Maybe an obscure thought but worth making sure it will fit ok into your intended imaging train.

Steve

Edited October 27, 2023 by teoria_del_big_bang

[Taman]

Another vote for a filter drawer, rather than a filter wheel. Also if you do get the wheel, you will need a ZWO T2 tilt adaptor to attach it to the camera. https://www.firstlightoptics.com/zwo-accessories/zwo-t2-camera-tilt-adjuster-ii.html

The 7 position wheel was designed for the higher end ZWO cameras which already have the tilt adaptor and the appropriate screw holes.

Tony.

[Elp]

Regarding filters you're looking at, you don't need both a dualband and the two separate dual combo ones, get one or the other set.

Regarding FW, considering how many hours you need to image to get a result, I just use a filter drawer or screw the filter into the image train and image one band throughout the night, why the need for the added expense. It would have a use for mono planetary imaging or if you were imaging a comet for example but for DSO, I don't see the need.

Edited October 27, 2023 by Elp

[ollypenrice]

15 hours ago, Elp said:

Why is a UV/IR cut filter recommended (for cameras with all pass front glass), and the lum is useless? The lum also cuts UV/IR?

I was assuming the camera would be appropriately filtered in this regard. This has been the case with all my OSCs but maybe some just have a clear filter, in which case you'd be right.

Olly

[Elp]

The majority of zwo ones have AR/anti reflective glass only, some of their cameras have slightly different spec glass.