Jump to content


The new Universe is in and working

  • Please log in to reply
132 replies to this topic

#126 wolfman_4_ever



  • -----
  • Posts: 1245
  • Joined: 15 Jul 2011
  • Loc: El Segundo, Ca, So. Cal

Posted 09 October 2012 - 04:31 PM


The ccd sensor used is a Sony ICX413AQS scientific grade class 0 only. Nothing else is used. Standard ICX413AQ is fine but does not have the sensitivity and low noise of the ICX413AQS. These sensors are very difficult to obtained.

Rock M.

Ah that's right... THE CHIP DUMMY! (referring to me).. Very nice.. The science grade chips are sweet.. And class 0 to boot? Excellent.....(As Mr. Burn's would say.....)

#127 GlennLeDrew


    Voyager 1

  • *****
  • Posts: 11145
  • Joined: 17 Jun 2008
  • Loc: Ottawa, Ontario, Canada

Posted 09 October 2012 - 06:42 PM

Vignetting with focal reducers has two primary sources.

1) The far field obstructor. Examples include the inner opening on SCT primary baffles, or Newtonian secondary mirrors. Due to their considerable distance from the focus, any vignetting they introduce is seen as a more gradual fall-off in illumination, beginning immediately from the edge of the circle of full illumination.

2) The near field obstructor, which here is the reducer's clear aperture. The vignetting introduced here is of a more rapid fall-off somewhere near the field edge, the 'sharpness' of the shadowing being due to the relative nearness of the the reducer to the focus.

A reducer in a cell of 2" OD does *not* require a 3" rear opening on the scope. Even a 2" opening is good. In fact, said rear aperture need be hardly larger than the reducer's clear aperture. Remember, the only light getting through to the focus is that which enters the reducer's front aperture; light outside this is of no account.

The Universe's 28.4mm diagonal demands of a reducer working at 0.5X a clear aperture of *at least* 2" if near field vignetting is to be minimal. This is impractical for most scopes. And so there is a sharp fall-off near the edges on the long dimension. But the component of far field vignetting, upon which the near field vignetting is superimposed, is not itself affected by the reducer, beyond the expected reduction in scale of the illumination profile. That is, whether a 0.5X reducer has a small or large clear aperture, the far field vignetting is the same, but the too-small reducer aperture superimposes its own component of sharper fall-off inside the field edge.

#128 mallin


    Vendor - Mallincam Video

  • -----
  • Posts: 93
  • Joined: 27 Jan 2011
  • Loc: Ontario Canada

Posted 09 October 2012 - 06:52 PM

John,You misunderstood my post. A output of 3" or more is required to avoid vignetting. When I tested on a SCT, the baffled draw tube where the mirror rides on is simply too small and too long in some case thus creating vignetting. But when I tried on on a Ritchey-Chretien optical tube (VRC 10), it has a 3"+ output at the rear where no vignetting were present. We tested the same on a TeleVueis and results were spectacular to say the least.
Hope this clear the misunderstanding. Regards,
Rock Mallin

So output does mean output... Thanks for clearing that up Rock.I used 3" focuser (output) for this same reason... the wide light cone of my f3.3 would cause vignetting with a 2" focuser.GregW :cool:

Ummm...So we need an expensive Ritchey-Chretien (VRC 10), TeleVue or equal with a 3" aperture focuser to avoid vignetting via the x0.5 FR :(


That depends of you telescope choice. Make sure if you use large sensors that your scope will be compatible to it. many SCT have a small and long mirror draw tube and cause vignetting to camera when used with a focal reducer. Just makes sense here. If you go too wide (field of view) some undesirable effect may result thus choosing the right telescope for the job is necessary. Good planning good judgement is key before spending all kind of money on stuff that may not be compatible to your telescope.

Low cost telescope = money saved. But will have to spend again to get it right with many new cameras on the market today. Its all up to you and about your budget.

At least we come forward saying "you need at least 3" of rear optical output".

Rock M.

#129 johnnyha


    Fly Me to the Moon

  • *****
  • Posts: 6511
  • Joined: 12 Nov 2006
  • Loc: Sherman Oaks, CA

Posted 07 November 2012 - 06:21 PM

Any more updates, reports or news about the Universe?

#130 nytecam


    Voyager 1

  • *****
  • Posts: 11603
  • Joined: 20 Aug 2005
  • Loc: London UK

Posted 08 November 2012 - 04:59 PM

Any more updates, reports or news about the Universe?

Agreed - it's a month since the last report :shocked:

#131 Lorence


    Viking 1

  • -----
  • Posts: 866
  • Joined: 15 Sep 2008

Posted 08 November 2012 - 05:46 PM

Any more updates, reports or news about the Universe?

I've started using a script that combines the Universe software with Deep Sky Stacker Live. Really enhances the video like aspects of the camera. I'm very pleased with the results.

#132 geminijk


    Viking 1

  • -----
  • Posts: 914
  • Joined: 03 Apr 2008
  • Loc: Murfreesboro, TN

Posted 11 November 2012 - 10:16 PM

I've started using a script that combines the Universe software with Deep Sky Stacker Live. Really enhances the video like aspects of the camera. I'm very pleased with the results.

So anything to share with us? Any video of that working?


#133 Raginar


    Fly Me to the Moon

  • *****
  • Posts: 6138
  • Joined: 19 Oct 2010
  • Loc: Rapid CIty, SD

Posted 12 November 2012 - 12:11 AM

I think they're posting them all in the Mallincam forums. I'd recommend heading over there. It would be nice to have a larger discussion on CN though.

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.

Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics