Venus with U-Filter, 25th May 2023

[lukebl]

Here's a capture of Venus this evening using the Baader U-Filter, with the results from some previous sessions at the same scale for comparison.

Captured with a 250mm f/4.8 Newtonian, 5x Powermate, ZWO ASI290MM Mini cam, Baader U-Filter and Baader IR-Pass Filter.

Up until now I have been aiming to capture as many images at as short an exposure as possible, generally around 25-30,000 frames at about 15ms. This evening I tried fewer (just 5000 frames) and longer (30ms)exposures, and rather counterintuitively the results seem as good as or better than my earlier attempts.

Processed in Autostakkert, Registax and Photoshop. RGB thus: R(IR), G(50%U/IR), B(U).

Apparently Venus's clouds rotate around the planet every 4.2 days, and it would be intersteing to see if any features are persisent and reappear at subsequent rotations.

[Ibbo!]

Vey nice and interesting experiment.

I have had an awful time trying to get focus with my UV on venus this time , any tips?

[Space Cowboy]

Nice capture! Seeing has been very good this week and Venus getting larger too, so it's all good 👍

[lukebl]

9 hours ago, Ibbo! said:

Vey nice and interesting experiment.

I have had an awful time trying to get focus with my UV on venus this time , any tips?

I struggle with focus too. I just focus in and out till it looks about right. Nothing scientific!

8 minutes ago, Space Cowboy said:

Nice capture! Seeing has been very good this week and Venus getting larger too, so it's all good 👍

True, it’s getting larger, but as it becomes more of a crescent there’s much less to see! Very frustrating.

[Space Cowboy]

3 minutes ago, lukebl said:

I struggle with focus too. I just focus in and out till it looks about right. Nothing scientific!

True, it’s getting larger, but as it becomes more of a crescent there’s much less to see! Very frustrating.

Yes, the next couple of weeks look like the sweet spot before the crescent becomes too pronounced.