Back to forums

UV/IR Cut Filters - Advice Please!

ZWO ASI533MC Pro Optolong L-Pro Equipment UV/IR Cut Filters
6 replies•144 views
Mark Germani avatar
Mark Germani avatar
Hi folks:

After recently working with data with more natural colour stars than I am able to get from my Optolong L-Pro even after SPCC, I've been rethinking my broadband imaging filter choice. I live in Bortle 7, and currently image with an Astro-Tech AT92 which is pretty well-corrected and an ZWO ASI533MC Pro which at bare minimum requires a UV/IR cut filter.

To whit, I'm wondering if you folks could recommend a good UV/IR cut filter. Would any off-the-shelf UV/IR cut filter work, or are there specific filters that I might want to consider? As the AT92 is well-corrected but is using a stock flattener, I was looking at the Astronomik L2.

The intended use of the filter would be for capturing RGB stars for my narrowband images from my Bortle 7 backyard, and imaging broadband targets from dark sites in the future (if I can ever get to one when it's actually clear).

I'm also wondering if it's worth shooting broadband targets with just the UV/IR cut from my Bortle 7 backyard. Am I asking for trouble with this approach?

Thanks in advance for any input!

CS,
Mark
Well Written Respectful Engaging
Ryan Génier avatar
Ryan Génier avatar
Hi Mark

I've used the Optolong UV/IR filter. Works well for my uses, haven't seen any issues. 

Just some advice w/ shooting broadband from the city (I'm also B7) - I've had nothing but issues. Every time I try and do it again, the gradients are an absolute mess and are a nightmare to process out. I eventually picked up a LPS-P2 light pollution filter to try and shoot luminance from the city. But overall broadband has been nothing but frustration.
Helpful Concise Supportive
Joel Lee avatar
Joel Lee avatar
Hi Mark, 

I believe that there are possible ways to go wrong with UVIR cut filters. I started with an SVBony UVIR 2 inch and highly recommend against it. It works if you aren't pursuing anything dim but it has pretty terrible halos that show up when you use it on super dim targets (see my Ghost Nebula image with star splotches all over) or brighter objects (this includes the star near T Coronae Borealis. I also feel like there's bloat but I can't really confirm that. Although much pricier, I recently got the Player-One AntiHalo and it does far better for the images I've tried with it so far. The images below are auto stretched in ASIFits Viewer except the Vega stack where I had to move the slider a little so that the background is similar to the rest otherwise it had a blue color cast. 

As for shooting broadband in the backyard in our light polluted skies, expect to use MUCH more integration than others at darker sights. 

SVBony UVIR on Arcturus 300s: 


SVBony UVIR on Vega 180s (sorry for the poor tracking):


Player One AntiHalo UVIR on Vega 152x5s:
Helpful
Mark Germani avatar
Mark Germani avatar
Ryan Génier:
Hi Mark

I've used the Optolong UV/IR filter. Works well for my uses, haven't seen any issues. 

Just some advice w/ shooting broadband from the city (I'm also B7) - I've had nothing but issues. Every time I try and do it again, the gradients are an absolute mess and are a nightmare to process out. I eventually picked up a LPS-P2 light pollution filter to try and shoot luminance from the city. But overall broadband has been nothing but frustration.

Thanks Ryan! I can appreciate that a lot of effort went into dealing with the gradients, but looking at your images that you took with the UV/IR you'd be hard pressed to tell - they're really fantastic! I think your broadband work is super. Thanks for weighing in on the Optolong CS!
Respectful Supportive
Alex Nicholas avatar
Alex Nicholas avatar
Joel Lee:
Hi Mark, 

----
SVBony UVIR on Arcturus 300s: 

SVBony UVIR on Vega 180s (sorry for the poor tracking):

Player One AntiHalo UVIR on Vega 152x5s:

I've tried a heap of different UV/IR cut filters too, and settled on the PlayerOne AntiHalo UV/IR cut (2"), I've found it to be fantastic, though I'm in bortle 4~5...
Mark Germani avatar
Mark Germani avatar
Thank you @Joel Lee and @Alex Nicholas - I had considered the Player-One a while back but started down the Astronomik rabbit-hole and forgot about it. Sounds like it's a good option! CS!
Well Written Respectful
Gilmour Dickson avatar
Gilmour Dickson avatar
I have had bad experiences (halos) with a cheap zwo ir/uv filter.  With an Astronomik L3 (which I bought when I was imaging with a doublet) there are no such problems.