LRGB filter recommendations

[james_screech]

I have a set of oldish ZWO LRGB filters, I just used eXcalibrator to estimate their colour balance ratios with my Atik414ex to try and improve my colour balance. I was very surprised at the results, which explain my problems with getting colour balance looking natural:

R: 1.00
G: 2.07
B: 2.44

Green and blue need more than twice the exposure of the red!

Can anyone recommend a filter set which will give a better colour balance for both my Atik414ex and ASI1600MM. I know ZWO have a set that are balanced for the 1600. Are they likely to be any good with the Atik as well or would I be better getting a set of Baader filters and comprimise between the two cameras? 

James

[wimvb]

Astrodon markets a set optimised for the kaf chip, and one for Sony chips. They seem to work ok.

iow, what’s your budget? 😉

I believe most manufacturerers have the same pass band on all three filters, ie 100nm per filter. It’s diffucult to taylor filters to all sensors. Where filters differ is in the gap between G and R (light pollution rejection) and the overlap between B and G (Oiii passband). I believe that Astrodon filters have a much wider gap between G and R, which is likely part of their colour balance strategy.
If I were you, I might look into the zwo set for the asi1600 and adjust my process to also fit the Atik.

Edited June 7, 2020 by wimvb

[Physopto]

Astronomik maybe. If you do buy a set of filters matched to one type of camera or CCD chip will they be any use when you invariably change to another CCD????

Seems a recipe for extra cost in the long run.

 

I found that the Baader filters (3mm glass adds 1mm to back focus) also a very thick/deep  metal fitting/mounting, so  I suspect caused some vignetting of the image.

 

Astronomik are very thin both in glass thickness (1.1mm so very little in back focus alteration) and metal fitting. Excellent backup and guarantee honoured as stipulated.

Astrodons are both thick glass (3mm, 1mm alteration in back focus) and very expensive, but excellent filters.

I own both Astrodons and Astronomik, both excellent filters.

Derek

[gorann]

12 minutes ago, Physopto said:

Astronomik maybe. If you do buy a set of filters matched to one type of camera or CCD chip will they be any use when you invariably change to another CCD????

Seems a recipe for extra cost in the long run.

 

I found that the Baader filters (3mm glass adds 1mm to back focus) also a very thick/deep  metal fitting/mounting, so  I suspect caused some vignetting of the image.

 

Astronomik are very thin both in glass thickness (1.1mm so very little in back focus alteration) and metal fitting. Excellent backup and guarantee honoured as stipulated.

Astrodons are both thick glass (3mm, 1mm alteration in back focus) and very expensive, but excellent filters.

I own both Astrodons and Astronomik, both excellent filters.

Derek

Just a small correction: Baader filters are 2 mm thick.

[james_screech]

33 minutes ago, wimvb said:

Astrodon markets a set optimised for the kaf chip, and one for Sony chips. They seem to work ok.

iow, what’s your budget? 😉

I believe most manufacturerers have the same pass band on all three filters, ie 100nm per filter. It’s diffucult to taylor filters to all sensors. Where filters differ is in the gap between G and R (light pollution rejection) and the overlap between B and G (Oiii passband). I believe that Astrodon filters have a much wider gap between G and R, which is likely part of their colour balance strategy.
If I were you, I might look into the zwo set for the asi1600 and adjust my process to also fit the Atik.

My budget is up to £250.

[Physopto]

2 hours ago, gorann said:

Just a small correction: Baader filters are 2 mm thick.

Thanks I forgot 😀

I actually did a few calculations when I was in the market for new filters and was designing my parts for CNC machining to add an SX AO unit and QSI camera to my newest scope (Baby Q). Fitting it all in was a bit tight so the filter also had an important  bearing on spacing.

 

 

Edited June 7, 2020 by Physopto

[wimvb]

3 hours ago, james_screech said:

My budget is up to £250.

That makes the choice easier. Filter, or rather, rim thickness can be an issue. Compare the filter characteristics of the various brands. Then study reviews and look at images. Look out for reflections. In the end, such things will matter more than exact colour balance, you will find out.

I know it’s more expensive, but if you keep the filters with the camera, you can create a workflow for each. Unless you can just swap cameras of course, without having to fiddle with spacers or adapters.

Edited June 7, 2020 by wimvb

[Xplode]

On 07/06/2020 at 12:42, gorann said:

Just a small correction: Baader filters are 2 mm thick.

It depends on the filters, 50.4mm and larger unmounted filters are 3mm while all the mounted and smaller unmounted filters are 2mm thick.

 

@james_screech How about just adjusting the exposure length or get a software with automatic color balancing like Pixinsight?
Remember that a "balanced" filter set blocks light to achieve that balance so you get lower SNR.

Edited June 11, 2020 by Xplode