Can I use an UV/IR cut filter in front of my regular LRGB?

[billyharris72]

Hi all:

I've been having a pretty serious issue with blue halos (and some more general scattering of blue light) in RGB and LRGB images taken on my ASI1600mm with Skywatcher ED72. I suspect it's down to the filters I'm using - I have tried ZWO 31mm unmounted with baffles and Astronomik unmounted (with have protective ring around the outside to remove the need for the baffle). Both sets of filters have the same issue, and I can see by eyeballing that both the L and B channels are prone to bloating and faint halos around stars.

The issue is similar to the one in the follwoing thread on the ZWO forum:

https://bbs.astronomy-imaging-camera.com/viewtopic.php?f=8&t=7435&sid=6d9f68ffe43b0620ab1e6719c5ec8f3d&start=10

Discussion on that thread seems to blame the issue on the bandpass of the blue and luminance filters (both the ZWO and Astronomik go to about 380nm) suggesting that this is just too far into the blue for an ED doublet to handle. One option would be to buy a different of filters (getting expensive). I noticed that someone on the thread eems to have gained a considerable improvement by mounting a Baader UV/IR cut filter in front of the filter wheel (probably in the flattener). I was thinking something similar, perhaps with an Astronomic L3 T2 filter mounted right on the front of the filter wheel, or a 48mm filter in the field flattener - that cuts off around 420nm or so, so I imagine it could potentially make a big difference.

I just wanted to ask peoples opinion on here before I spend yet more money though - does this seem like a sensible solution?

Cheers,

Billy.