Jump to content


Photo

5-100mm F1.4 Auro Iris Varifocal CCTV Lens

  • Please log in to reply
5 replies to this topic

#1 Moromete

Moromete

    Viking 1

  • *****
  • Posts: 677
  • Joined: 15 Feb 2012
  • Loc: Romania

Posted 15 February 2013 - 10:16 AM

What happens if we use a 5-100mm F1.4 Auto Iris Varifocal CCTV Lens on a CCTV with DC Iris to view large DSOs (e.g. M31,etc)?

Considering the lens has Auto Iris, will the CCTV keep the iris wide open at night when shutter speed is on manual?

I'm talking about a lens like this http://www.spy-shop....ala-cu-auto-... .

If I'm not wrong, the image scale of DSOs with this lens+CCTV will be similar to the one given by a APS-C DSLR + ST80 scope, considering the much smaller sensor of the CCTV and inherent magnification (I think 4 times more than a APS-C DSLR).

#2 Moromete

Moromete

    Viking 1

  • *****
  • Posts: 677
  • Joined: 15 Feb 2012
  • Loc: Romania

Posted 15 February 2013 - 11:00 AM

Or maybe this lens is better having manual iris too? http://www.bhphotovi...AS_13VM20100...

#3 Moromete

Moromete

    Viking 1

  • *****
  • Posts: 677
  • Joined: 15 Feb 2012
  • Loc: Romania

Posted 17 February 2013 - 11:11 AM

Anyone?

#4 bhuvfe

bhuvfe

    Explorer 1

  • -----
  • Posts: 84
  • Joined: 14 Jan 2011

Posted 17 February 2013 - 01:36 PM

http://www.cloudynig...5359670/page...

Maybe of interest?

#5 ccs_hello

ccs_hello

    Fly Me to the Moon

  • *****
  • Posts: 6545
  • Joined: 03 Jul 2004

Posted 17 February 2013 - 02:35 PM

The linked one (sold by BH) is a cheapie.
On that 20-100 f/1.6 zoom, f/1.6 is not going to happen on the long focal length side.

For astro application...

Bottom-line, unless you can get a deeply discounted (e.g., one cent on the dollar) used "Studio Grade" video camera lens (you still have to do your own lens mount adaptation), you'd rather get a telescope OTA.

Also, (again for astro), do not use any form of IRIS control! Keep it wide open.

Clear Skies!

ccs_hello

#6 Moromete

Moromete

    Viking 1

  • *****
  • Posts: 677
  • Joined: 15 Feb 2012
  • Loc: Romania

Posted 18 February 2013 - 04:42 AM

Thank you.






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics