Badder U-Filter 350nm

[multiweb (Marc)]

I'm giving a go at Venus with a ASI462MC Wednesday with a broadband Baader U-Filter centered on 350nm with a 40nm bandwidth. I can't find a QE curve under 400nm for the camera. Has anyone tried it at anything lower than 400nm?

[rustigsmed (Russell)]

hi Marc,

I have a similar filter on the way "Antlia u-Venus" (hopefully by Wednesday too) and I couldn't find a chart under 400nm for my cameras either... I am gathering it will be reasonably low in the qe but should still get some kind of a result..

cheers

russ

[multiweb (Marc)]

I saw a pic that I'd be stoked with getting the details I'm seeing done with an ASI174 mono which is only 20% QE at 350nm. So I reckon there's hope.

[rustigsmed (Russell)]

here is one with the zwo 120mm is getting some detail but noisy https://www.astrobin.com/272711/

should be ok

[multiweb (Marc)]

Originally Posted by rustigsmed

here is one with the zwo 120mm is getting some detail but noisy https://www.astrobin.com/272711/

should be ok

That's bloody good too. I have an old 120MM USB2.0 but I don't think it's fast enough.

[Camelopardalis (Dunk)]

Given the pics for the Antlia U filter use a 290 mono, I’d say the 462 would do a fair job…the latter is a 290 dialled up to 11. What colours you’d end up with is a different question, since it only comes in OSC…

[multiweb (Marc)]

Originally Posted by Camelopardalis

Given the pics for the Antlia U filter use a 290 mono, I’d say the 462 would do a fair job…the latter is a 290 dialled up to 11. What colours you’d end up with is a different question, since it only comes in OSC…

Likely will grab mono data for UV then shoot IR to work out some bicolour blend. I suspect the UV will land in the blue pixels. The rest will be noise. Still has a reasonable QE in blue at 400nm.

[multiweb (Marc)]

I can get 100fps in UV but I have to push the gain to 500. So that gives me ~10000 frames for 90s. IR flies in comparison. I can get 25000 frames in 90s. Seeing's still a bit dodgy tonight but I have my profiles set for tomorrow night.

[multiweb (Marc)]

Got some decent data tonight. Also tried UV on Jupiter. Could get only 14fps though. Saturn would be way too dim. Seeing was so so but should be a lot better tomorrow. All set up now.

[rustigsmed (Russell)]

Originally Posted by multiweb

I can get 100fps in UV but I have to push the gain to 500. So that gives me ~10000 frames for 90s. IR flies in comparison. I can get 25000 frames in 90s. Seeing's still a bit dodgy tonight but I have my profiles set for tomorrow night.

that's great Marc, looking good

[Camelopardalis (Dunk)]

Great results Marc

I’ve been obsessively hunting for a Baader Johnson-Bessel, but they’re discontinued

Speculatively extrapolating the QE curves of these cameras into the shorter wavelengths doesn’t look great compared to peak visual or in IR bands, but it’s undoubtedly better than what was possible only a few years ago for us hobbyists