Venus UV with mono and colour camera

[Kon]

I have been using my cheap Astromania UV filter on Venus and I did a side by side test with a mono and colour camera (based on some offline discussions). Cheap filters seem to suffer from ghosting. It seems to be more of an issue with my colour asi462mc than the mono Altair Astro GPCAM 290M (thanks again @CraigT82). So the filter itself is good (from my limited experience) and it is something to do with the colour cameras? First image altair after i tidied the ghosting and some post processing, second after registax and third with asi. ASI is also not that sensitive at that wavelength either. I also got some data in IR, not many clouds this time,  and made the colour version of the clouds (last image, 200% resized). 8" Dob, manual, 2.5x TV powermate.

 

[Space Cowboy]

Proper ghosting on that colour cam for sure. Would be interesting to see what effect a ADC would have.

Still nice detail on the mono! What alt were you imaging at?

[BGazing]

This is really nice, actually, a very decent effort.

Just got a hold of TS #47 and here are its scans (another plot is new L2 by Astronomik). I bet it is the same #47 that FLO sells under a different brand, worth trying - has all the best UV real estate plus some violet.

[Kon]

6 hours ago, Space Cowboy said:

Proper ghosting on that colour cam for sure. Would be interesting to see what effect a ADC would have.

Still nice detail on the mono! What alt were you imaging at?

I don't have an adc. It was at 16 degrees so quite low. Looking forward to later in the season but good to get the teething issues out of the way.

[Kon]

3 hours ago, BGazing said:

This is really nice, actually, a very decent effort.

Just got a hold of TS #47 and here are its scans (another plot is new L2 by Astronomik). I bet it is the same #47 that FLO sells under a different brand, worth trying - has all the best UV real estate plus some violet.

Thanks for the info. I will take a look while I am contemplating to buy a mono camera.

[CraigT82]

Nice comparison shots, yes some definite reflections going on I think, possibly between sensor and AR coated window or maybe even the window and the barlow? Most AR coatings don’t work too well below 400nm. 

I removed the window on that 290m as I wanted as little glass as possible between the planet and the sensor, theory being that glass absorbs UV light but also wanted to do away with those AR coatings on the window. I also bought the APM 2.7x barlow as it was rumoured to have coatings with good transmission below 400nm and is a very good 2 lens barlow, which theoretically should transmit more UV than a 4 lens telecentric as it’s got half the number of coated surfaces. 

[Space Cowboy]

On 03/03/2023 at 16:31, Kon said:

I don't have an adc. It was at 16 degrees so quite low. Looking forward to later in the season but good to get the teething issues out of the way.

Don't know whether you've seen this discussion on cloudy nights regarding the reflection issue.

https://www.cloudynights.com/topic/807242-venus-night-side-1-micron-thermal-image-on-dec-23rd/page-2#entry11691626

 

[Kon]

21 minutes ago, Space Cowboy said:

Don't know whether you've seen this discussion on cloudy nights regarding the reflection issue.

https://www.cloudynights.com/topic/807242-venus-night-side-1-micron-thermal-image-on-dec-23rd/page-2#entry11691626

 

No, thanks. I will have a read.