Filters to use with ZWO color cameras

[bluesilver]

Hi, So i have made the move from DSLR to a dedicated astronomy camera.
I have a ZWO asi017mc
I have yet to try it out due to bad weather and also work commitments, but from what i have researched so far ( am i am still a tad confused ) but it looks like i might need to look at filters even though it is a color camera.

So please correct me if i am wrong here, but do i need to look at a Luminance filter, ( i think these are just UV / IR cut filters?)
Do i need to look at a narrow band filter? ( still not sure what the difference is between Luminance and narrow bad filters )

I might be getting a tad ahead of myself here as i have yet to see if my setup will reach focus, My scope is not ideal from astrophotography
( Skywatcher Evostar 150ED )
http://www.astroanarchy.com.au/telescopes/Skywatcher_ED150_Deluxe.html
There is a 2" T-adaptor that the Canon T-ring attaches to, I have just taken the T-ring of and attached the camera in question to this.

Any advice or information is appreciated.
Thanks.
peter.

[Nikolas]

I use the Optolong L-Extreme L-enhance as well as the Optlong L-Pro, and the zwo ir-cut filters each has their purpose and all are extremely good.

[Startrek]

Peter,
Your 071MC only has an AR window ( no IR cut filter ) which is fine for imaging with reflector telescopes
However if your imaging with a refractor I’d recommend you buy an IR cut filter for RGB imaging
You can image narrowband with your 071MC so will need a Duoband or multiband filter
I use an Optolong L Exteme which is insanely good ( look at my images in Deep Space section using the L Extreme )
If your imaging narrowband with a refractor, I’m not sure if you need the IR cut filter and the narrowband filter as my 2600MC already has an IR cut internal
Maybe others can advise ( I don’t image with refractors on reflectors )

Narrowband filters are mainly used for imaging Emission Nebula under moon light skies or light polluted skies , I use mine in both Bortle 8 and Bortle 3 with or without the moon and get incredible results
The narrowband filter only allows certain wavelengths of light through to the camera sensor , namely Ha and Oiii
The L Extreme passes 7Nm of Ha and 7Nm Oiii which is excellent

Maybe others can help in regard to IR cut and Narrowband if you image with a refractor ?
Cheers
Martin

[The_bluester]

From my experience of a zwo with an AR only window and a refractor, you are likely to want an IR cut filter (Which in most cases I have actually seen is a UV-IR cut) or you could see some spectacular reflection issues.

A quick rundown on the various filters.

Luminance - A broadband filter which more or less passes everything from the near infra-red to the near ultravoilet. The ZWO "IR" filter cuts both IR and UV ends, I would consider it to be a luminance filter. You can get these in various passbands, my old SCT had some real reflection issues so I used an Astronomik L2 filter which cut more out of the ends of the spectrum and improved the situation markedly.

Red-Green-Blue - Broadband filters which pass only the intended section of the spectrum. Narrowband filters - "Notch" filters which pass only a very specific wavelength, they come in various passband widths, generally the tighter the passband, the more they cost! The very narrow pass filters can be used to pick off elements which emit light at very similar wavelengths. With varying degrees of usefulness you can use all of these with mono sensors as they are generally intended, or with OSC colour sensors.


Multi band pass filters (like the L Extreme Martin mentions) these pass two or more individual "Notches" so you can for instance image in Hydrogen Alpha and Oxygen 3 at the same time, they are only particularly useful with colour sensors where the HA and Oiii will show up on different colour pixels.


If I were putting my money down in your situation I would put it together first and make sure it is able to come to focus, then put a very bright star in the frame and see if it is showing any reflection oddities, if it does, some form of IR cutting filter is likely to help.

[bluesilver]

Thanks for the replies and advice, very much appreciated.
I have some good information there now to research up on.

Yes, first step is to get it all mounted, connected and see if i can reach focus with the setup, then start from there.

Should be a good learning curve for sure.
Thanks again.
Peter.

[RyanJones]

Peter,

Something that hasn’t been mentioned is integration time. Be aware that any sort of narrowband ( dual band or single band pass as opposed to UV/IR or Luminance) significantly increases the length of your subs or total integration time required to image. This is going to mean that your mount will have to be performing well and your guiding has to be better. I only mention it because sounds like you’re at the start of your AP journey and may not be aware of the challenges these options present. Well worth it but be wary which end of the pool you want to jump in.

Cheers

Ryan