Which UV-IR filter

[luka]

Few of us are building a camera (http://www.iceinspace.com.au/forum/showthread.php?t=146493) based on the ICX453AQ sensor and the question arose which UV-IR blocking filter to use at the front. The filter will also seal the camera from the outside world. We are looking at Astronomik luminance filters (http://www.astronomik.com/en/neue-produkte-new-products/luminance-filter-l-1-l-2-l-3.html). Astronomik offers 3 filters with different spectral properties (L1, L2 and L3, as in the link above). The choice will clearly depend on the rest of the gear used.

I am using SkyWatcher ED80 (gold) + Hotech SCA flattener. I used Baader UV-IR cut with my IR modded DSLR and it worked well (until I dropped the filter and smashed it). Baader filter has the same IR transmission cutoff as the Astronomik L2 but it looks more like L3 at the UV end so I am not sure if L2 or L3 would be a better choice.

Any hints would be greatly appreciated.

[Merlin66]

Luka,
Looking at the graphs, unless you want to record data in the CaK-H region then either of the L2 or L3 would do the job.

[luka]

Thank you Ken.

Just wondering, are there any other advantages of L2 over L3 apart from more light due to slightly larger transmission range?

[Merlin66]

For conventional AP imaging, no I don't see any significant difference.