Jump to content

  •  

CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.

Photo

Venus UV: ASI290MM vs. ASI178MM

  • Please log in to reply
4 replies to this topic

#1 jragsdale

jragsdale

    Viking 1

  • *****
  • topic starter
  • Posts: 620
  • Joined: 07 Dec 2015
  • Loc: Idaho

Posted 22 January 2020 - 01:20 AM

I'm getting my Venus UV imaging setup going. Currently using an ASI183MM Pro for the camera but would like to move to a dedicated cam that I can remove the AR window for better exposures. Which one would do better though, ASI290MM or ASI178MM? Both small pixels, 290 has a higher SNR but the 178 has better UV transmission. Thoughts? Surely they would both be great, but at the same price, which would be better? Assuming an 8" f/6 newt, Astrodon UVenus Filter and a 2x barlow...



#2 Kokatha man

Kokatha man

    Voyager 1

  • *****
  • Posts: 14,251
  • Joined: 13 Sep 2009
  • Loc: "cooker-ta man" downunda...

Posted 22 January 2020 - 03:21 AM

...makes sense Jordan - I have never concentrated that much on Venus to consider your intended approach, but comparing the clear (AR) window graph of the ASI cameras to the uVenus filter's bandpass tells the story. wink.gif

 

That said, as I commented in another Venus thread here recently that after years of thinking that the SCT & Venus cloud detection was a hard task, the discovery that dropping the histogram to around 30% made all the difference for us & clouds began to spring out of the captures..! lol.gif

 

I won't dedicate a camera to it personally, however... wink.gif

 

ASI-ClearWindowVsAstrodonuVenusGraphs.jpg


  • jragsdale likes this

#3 jragsdale

jragsdale

    Viking 1

  • *****
  • topic starter
  • Posts: 620
  • Joined: 07 Dec 2015
  • Loc: Idaho

Posted 22 January 2020 - 04:02 AM

Yes, definitely a lot to gain by getting rid of that window! I thought about getting a replacement fused silica window but I was looking at around $100. It seems a lot better, easier and cheaper to just go without and keep the Uvenus filter attached to the camera in use and change it out to an IR cut when doing other tasks. Now just to pit these 2 great cameras against each other! 



#4 CPellier

CPellier

    Apollo

  • -----
  • Posts: 1,455
  • Joined: 07 Aug 2010

Posted 22 January 2020 - 04:50 AM

Don't forget to consider the sampling. With an F/6 instrument and a 2x barlow which is quite likely to operate at a real 2,5x factor, the focal lenght would be a bit too long for a camera with pixels of 2,4µm. Even more too long if you put an ADC in the optical train. 

I have not tested the ASI178MM but the ASI290MM is working well in UV and has pixels of 2,9µm probably more suited to your instrumentation.

By the way, the ASI183MM is also excellent on the UV/violet part...



#5 jragsdale

jragsdale

    Viking 1

  • *****
  • topic starter
  • Posts: 620
  • Joined: 07 Dec 2015
  • Loc: Idaho

Posted 22 January 2020 - 06:53 PM

By the way, the ASI183MM is also excellent on the UV/violet part...

I've been using mine as is for now and it does seem to work well. But since it's a cooled camera and my main DSO camera, I don't want to risk taking the window off and having window frost issues or dust after the fact. Better to do it on a dedicated smaller (cheaper) camera, haha. 


  • CPellier likes this


CNers have asked about a donation box for Cloudy Nights over the years, so here you go. Donation is not required by any means, so please enjoy your stay.


Recent Topics






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics