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Which Astronomik UV/IR cut filter?

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#1 AstroPepe

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Posted 16 October 2019 - 03:18 PM

Hi :) i was looking uv/ir cut filters and astronomik has 3 different filters. L1, L2, L3. I think the L2 is the best choice for me. I have modified Canon 1100d (full spectrum) and i am planning to get flattener soon :D Can somebody tell me which one is the best choice. Astronomik UV/IR cut L2 filter is most similar to optolong uv/ir cut filter.

#2 scadvice

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Posted 16 October 2019 - 05:08 PM

I went with the Optolong UV/IR which matched closely with the Astronomik Luminance filter L2 because I had others of Optolong filters and have been happy with them. 

 

The L1 is suppose to be for scopes that have excellent correction and I was temped to get that one as my scope is in that category. But, the Astronomik site suggested the L2 when using the flattener/reducers. So, the open question for me was...Given excellent scope optics, how do I determined the right filter (L1 or L2)?  I have no method to test other than purchasing both L1 and L2 plus the Optolong and doing image comparisons. I'm not rich enough to do that!

 

I'm going to AIC here in the US next month so hopefully I can talk to Astronomik and Optolong to clear up my own confusion.

 

https://www.astronom...2-l-3.html?p=2 

 

https://www.highpoin...CgaAugqEALw_wcB



#3 AstroPepe

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Posted 17 October 2019 - 01:04 AM

I went with the Optolong UV/IR which matched closely with the Astronomik Luminance filter L2 because I had others of Optolong filters and have been happy with them.

The L1 is suppose to be for scopes that have excellent correction and I was temped to get that one as my scope is in that category. But, the Astronomik site suggested the L2 when using the flattener/reducers. So, the open question for me was...Given excellent scope optics, how do I determined the right filter (L1 or L2)? I have no method to test other than purchasing both L1 and L2 plus the Optolong and doing image comparisons. I'm not rich enough to do that!

I'm going to AIC here in the US next month so hopefully I can talk to Astronomik and Optolong to clear up my own confusion.

https://www.astronom...2-l-3.html?p=2

https://www.highpoin...CgaAugqEALw_wcB

Thank you :) I really hope you can get more information. I think I should go with l2 because its similar to optolong and i have seen very good results with that :D

#4 mxpwr

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Posted 17 October 2019 - 10:05 AM

Don't get a clip in filter. They tend to create nasty reflections.

#5 Sven_Bortle5

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Posted 17 October 2019 - 10:38 AM

Don't get a clip in filter. They tend to create nasty reflections.

I have a modified Canon 70D and use the clip-in Astronomik-filters as well as the Optolong L-Pro all of the time. Never had issues with reflections.



#6 Starman27

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Posted 17 October 2019 - 11:08 AM

+1 I haven't had any problems with clip in filter and my Canon 60Da.



#7 AstroPepe

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Posted 17 October 2019 - 11:52 AM

I am going to buy the 2 inch filter because its cheaper :D

Edited by AstroPepe, 17 October 2019 - 11:52 AM.


#8 mxpwr

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Posted 17 October 2019 - 12:17 PM

I am going to buy the 2 inch filter because its cheaper :D

Good choice. I have the astronomik clip in, which gives annoying reflections when the stars get too bright.
Now I changed to the 2 inch optolong and the difference is huge.
I think since the clip in filter is so close to the sensor and the filters "only" have ~96% transmission, the remaining 4% can lead to out of focus ghosts of bright objects.
The 2 inch filter is naturally much further away from the sensor, so even if you get double reflected light, it's miles out of focus.

Edited by mxpwr, 17 October 2019 - 12:18 PM.


#9 AstroPepe

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Posted 17 October 2019 - 02:18 PM

Good choice. I have the astronomik clip in, which gives annoying reflections when the stars get too bright.
Now I changed to the 2 inch optolong and the difference is huge.
I think since the clip in filter is so close to the sensor and the filters "only" have ~96% transmission, the remaining 4% can lead to out of focus ghosts of bright objects.
The 2 inch filter is naturally much further away from the sensor, so even if you get double reflected light, it's miles out of focus.

Okay!! I have skytech cls-ccd clip in filter and stars look good. Can i use the uv/ir cut filter on camera lens? Does it go on top of it?

Edited by AstroPepe, 17 October 2019 - 02:22 PM.


#10 mxpwr

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Posted 17 October 2019 - 03:09 PM

I'm using a Stepdown filter to attach it to the 72mm lens front.
This might give you some vignetting, especially if you have a full format.
But should be easy to compensate with a proper flat field.
It's barely visible with my aps-c sized sensor.

Note that this will increase your F Number since you reduce the lens diameter, i.e. less photons making it through your lens.

If i have some time this weekend, I can maybe post 2 flat fields with a full format and aps-c with the the filter attached to the front.

Edited by mxpwr, 17 October 2019 - 03:11 PM.



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