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UV/IR filters - halo comparison

ZWO ASI2600MC Pro Equipment Filters Review
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Lorand Fenyes avatar
Lorand Fenyes avatar
As a point of interest I would like to share it with you, it might be useful for others. The review was carried out at the same time, under the same conditions and with the same exposures. Both the blue star test (Alpheratz) and the yellow star test (Mirach) were performed the same linear streched processing steps to ensure accurate comparisons.

3 x 30mp light, 15 x 30mp dark, flat. 400/1820 Newtonian telescope, ZWO ASI 2600MC Pro, TeleVue Paracorr Type-II 



update:  Maybe I will repeat these test images with a different camera without a bulit-in filter later. The above series is absolutely good for showing the differences between filters, but the factory block filter can be a little bit misleading due to the double reflection.
Tony Gondola avatar
Tony Gondola avatar
Great work. The Astronomic IR block filter looks like the winner as my camera (585) is a perfect candidate for what that filter was designed for.
patrice_so avatar
patrice_so avatar
Hi, 

Thanks for sharing. This is indeed a very interesting post. 

I am bit surprised. Here is 570s of Vega with a optolong uvircut and an ASI294MC pro. There is a halo, but it is quite diffuse. I don't see the clear circle your example exhibits. 

Clear skies, 

Patrice 
Lorand Fenyes avatar
Lorand Fenyes avatar
patrice_so:
Hi, 

Thanks for sharing. This is indeed a very interesting post. 

I am bit surprised. Here is 570s of Vega with a optolong uvircut and an ASI294MC pro. There is a halo, but it is quite diffuse. I don't see the clear circle your example exhibits.

Patrice as I wrote, I processed the images in equal proportions and exactly the same, but I streched them heavily to show the differences. This is necessary because although these halos are not visible in the plain base raw images, they can easily come up from the background when the faint details of the deep-sky images are carefully post-processed. Then it does matter what filter you use. I did the test to find the right one for me.
Jan Erik Vallestad avatar
Jan Erik Vallestad avatar
How does it compare to an image without any of these filters? I'm only asking as the 2600MC already has a built in UV/IR cut filter. They call it IR-cut but as per the charts they aren't too dissimilar.

The built in filter:


Antlia:


Astronomik:
Lorand Fenyes avatar
Lorand Fenyes avatar
This is a perfectly valid point! Unfortunately I'm off that topic so I wouldn't be able to do the same test. Also, it is a fact that double filtering is not a completely good pattern. It can be used to compare the difference between the filters, but in general it really doesn't show the quality of the filter, because there is another glass behind it (possible reflexion).
Arny avatar
Arny avatar
Lorand Fenyes:
As a point of interest I would like to share it with you, it might be useful for others. The review was carried out at the same time, under the same conditions and with the same exposures. Both the blue star test (Alpheratz) and the yellow star test (Mirach) were performed the same linear streched processing steps to ensure accurate comparisons.




this is a very helpful comparison, Lorand.
Good to see my Baader is doing ok on blue stars, yet not soo much on red ones.

You don't happen to have done it with dualband filters and just by chance on a very fast f/2 system, do you?

Arny
Lorand Fenyes avatar
Lorand Fenyes avatar
this is a very helpful comparison, Lorand.
Good to see my Baader is doing ok on blue stars, yet not soo much on red ones.

You don't happen to have done it with dualband filters and just by chance on a very fast f/2 system, do you?

Arny

I will try to get some of them and test make a dual comparion too.