Return to the Cloudy Nights Telescope Reviews home page


Astrophotography and Sketching >> CCD Imaging & Processing

Pages: 1 | 2 | (show all)
Mike7Mak
Pooh-Bah
*****

Reged: 12/07/11

Loc: New York
Re: Very strange problem with meade dsi 2 pro new [Re: astrovienna]
      #5664168 - 02/05/13 07:00 PM

I certainly agree with 'ain't broke don't fix' and if something works it works. There's so many variables involved with guiding it's near impossible to make any universal rules, especially as you say, with 'mid-range' mounts (which I think is being kind to the LX200).

It wasn't until I ran PemPro that I was able to go beyond 2 seconds. Before that the PE was so ragged it made seeing the least of my problems.


Post Extras: Print Post   Remind Me!   Notify Moderator  
korborh
scholastic sledgehammer
*****

Reged: 01/29/11

Loc: Arizona
Re: Very strange problem with meade dsi 2 pro new [Re: astrovienna]
      #5664416 - 02/05/13 10:13 PM

I just checked my DSI 2 pro downloads and I see no difference between MaximDL subframe and full-frame. They are both almost instantaneous download. So 1.3sec seems odd, unless it is running in USB1 mode.

Post Extras: Print Post   Remind Me!   Notify Moderator  
astrovienna
Carpal Tunnel


Reged: 12/04/06

Loc: The NoVa White Zone
Re: Very strange problem with meade dsi 2 pro new [Re: korborh]
      #5664454 - 02/05/13 10:51 PM

Quote:

I just checked my DSI 2 pro downloads and I see no difference between MaximDL subframe and full-frame. They are both almost instantaneous download. So 1.3sec seems odd, unless it is running in USB1 mode.




Does it show you how much time elapses between data points?


Post Extras: Print Post   Remind Me!   Notify Moderator  
korborh
scholastic sledgehammer
*****

Reged: 01/29/11

Loc: Arizona
Re: Very strange problem with meade dsi 2 pro new [Re: astrovienna]
      #5664495 - 02/05/13 11:33 PM

Plotted data points for 1s exposures are ~3s apart. So there is an annoying latency which I always had and not sure where its coming from. My mount is very forgiving though and so this is not an issue for me.

Before getting the dsi 2 pro I was planning to get a video camera for guiding with reduced latency, but deferred the idea until I decide to so planetary imaging.


Post Extras: Print Post   Remind Me!   Notify Moderator  
jgraham
Postmaster
*****

Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
Re: Very strange problem with meade dsi 2 pro new [Re: korborh]
      #5665162 - 02/06/13 12:35 PM

I've used a DSI Pro I, II, and III as well as the DSI III to guide an LXD75 and an Atlas EQ-G. I've also used a guidescope and an off-axis guider. The vast majority of the time I use 1 second exposures. I never use anything shorter, but I have gone as long as 5 seconds. I never paid much attention to the download times.

Post Extras: Print Post   Remind Me!   Notify Moderator  
astrovienna
Carpal Tunnel


Reged: 12/04/06

Loc: The NoVa White Zone
Re: Very strange problem with meade dsi 2 pro new [Re: korborh]
      #5665216 - 02/06/13 01:04 PM

Quote:

Plotted data points for 1s exposures are ~3s apart. So there is an annoying latency which I always had and not sure where its coming from.




Well, darn. I was hoping you were getting rapid downloads, meaning that I might be able to as well.

I suppose what I really should do is buckle down and do some controlled tests to compare the Flea3 and DSI. But testing time always competes with imaging time!

Kevin


Post Extras: Print Post   Remind Me!   Notify Moderator  
jgraham
Postmaster
*****

Reged: 12/02/04

Loc: Miami Valley Astronomical Soci...
Re: Very strange problem with meade dsi 2 pro new [Re: astrovienna]
      #5665417 - 02/06/13 02:41 PM

Hmmm, isn't the Flea3 a 12 bit streaming video camera? The DSI is a 16 bit still frame camera. It wouldn't surprise me that it would have a much slower data transfer rate. I've also done lunar and planetary imaging with my DSI's. They work okay in that role, but they are no match for dedicated lunar and planetary cameras. I've also done some limited deep sky imaging with my Imaging Source cameras and the reverse is also true.

Post Extras: Print Post   Remind Me!   Notify Moderator  
neptun2
scholastic sledgehammer


Reged: 03/04/07

Loc: Bulgaria
Re: Very strange problem with meade dsi 2 pro new [Re: jgraham]
      #5665438 - 02/06/13 02:49 PM

Interesting discussion definitely. Next time i will check PHD logs to see how much time pases between 2 corrections with 1 second exposures. During guiding i monitor the corrections size and direction at least for the first 5 minutes to see that everything is ok and i do not remember to have seen 3 seconds interval without correction. Anyway next time under the stars i will definitely check it.

Post Extras: Print Post   Remind Me!   Notify Moderator  
astrovienna
Carpal Tunnel


Reged: 12/04/06

Loc: The NoVa White Zone
Re: Very strange problem with meade dsi 2 pro new [Re: neptun2]
      #5665946 - 02/06/13 08:11 PM

Yeah, there's definitely a reason the Lodestar costs $650. Same chip as the DSI 2, but with fast downloads (0.1 second from what I hear).

Neptun2, PHD actually saves all your logs in your Documents folder, so you may not need to wait for a clear night.


Post Extras: Print Post   Remind Me!   Notify Moderator  
korborh
scholastic sledgehammer
*****

Reged: 01/29/11

Loc: Arizona
Re: Very strange problem with meade dsi 2 pro new [Re: astrovienna]
      #5666051 - 02/06/13 09:29 PM

Well the download from my DSI 2 pro seems to be quite fast, a fraction of a second. However, guide corrections have much higher latency. I would think Metaguide with video camera will not have this latency. Not sure if it the camera or Maxim.

Post Extras: Print Post   Remind Me!   Notify Moderator  
astrovienna
Carpal Tunnel


Reged: 12/04/06

Loc: The NoVa White Zone
Re: Very strange problem with meade dsi 2 pro new [Re: korborh]
      #5666207 - 02/06/13 11:00 PM

I get the same latency with PHD, so I think it's the camera. Too bad - the DSI really is an excellent guide cam otherwise, and it's a lot cheaper than a Lodestar (especially when I already own one!) Metaguide certainly has very low latency, but I think any guide program would have that with video cams.

Kevin


Post Extras: Print Post   Remind Me!   Notify Moderator  
neptun2
scholastic sledgehammer


Reged: 03/04/07

Loc: Bulgaria
Re: Very strange problem with meade dsi 2 pro new [Re: astrovienna]
      #5666464 - 02/07/13 05:19 AM

Well i did not know that PHD stores log file in My documents by default. Thank you for pointing that to me. Well from the log it looks like you are correct. Here is part of the log:

Tue Feb 05 01:32:26 2013 Dir = 1, Dur = 20
Tue Feb 05 01:32:29 2013 Dir = 2, Dur = 79
Tue Feb 05 01:32:32 2013 Dir = 2, Dur = 33
Tue Feb 05 01:32:35 2013 Dir = 2, Dur = 79
Tue Feb 05 01:32:38 2013 Dir = 3, Dur = 233

So it really looks like there is such latency. Well as far as it guides well i am not worried about this but it is interesting fact anyway.


Post Extras: Print Post   Remind Me!   Notify Moderator  
Pages: 1 | 2 | (show all)


Extra information
6 registered and 17 anonymous users are browsing this forum.

Moderator:  Oldfield, droid, bilgebay, WOBentley, dr.who 

Print Thread

Forum Permissions
      You cannot start new topics
      You cannot reply to topics
      HTML is disabled
      UBBCode is enabled


Thread views: 1161

Jump to

CN Forums Home




Cloudy Nights Sponsor: Astronomics