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

Using refractor APO for photometry

Refractor Equipment
  • Please log in to reply
5 replies to this topic

#1 Fernando Alonso Velez

Fernando Alonso Velez

    Lift Off

  • -----
  • topic starter
  • Posts: 1
  • Joined: 01 Dec 2023
  • Loc: Bogotá - Colombia

Posted 13 February 2024 - 10:52 PM

Recently, I begin to preparate an equipment thinkng to do photometry, and following the AVSSO tutorial is posible to do this even with a DSLR camera and small lenses, however I like use a refractor APO (~4') with a focal lenght about 700mm, but I wolud like to know about experiences doing photometry with this OTAs. Some question that I've are:
Is necesary an refractor APO? or acromatic is enogh?
Is a  6' RC a better option?
I thank your sugggestion and comments


  • Xilman likes this

#2 pbealo

pbealo

    Apollo

  • *****
  • Posts: 1,410
  • Joined: 12 Oct 2006
  • Loc: New Hampshire

Posted 14 February 2024 - 08:48 AM

An achromat is fine, APO will work just fine as well.

 

More aperture will allow imaging fainter stars. But 4" is fine. "Use what you have".

 

Peter B.


  • Fernando Alonso Velez likes this

#3 Ed Wiley

Ed Wiley

    Vanguard

  • *****
  • Posts: 2,460
  • Joined: 18 May 2005
  • Loc: Texas, USA

Posted 14 February 2024 - 09:58 AM

Fernando,

 

Have a look at https://www.aavso.org/aavsonet-history and you will see that AAVSO has been using small scopes extensively to monitor bright stars. Even a 60mm refractor (or 50mm for that matter) is useful, all you have to do is pick appropriate stars. Many of the brighter stars of interest are too bright for larger scopes and are under-observed. Also, note that you don't need an expensive camera.. I use a 183-chip based cooled mono CMOS with BVI on my 3" refractor.

 

Ed


  • Jamey L Jenkins and Fernando Alonso Velez like this

#4 Jamey L Jenkins

Jamey L Jenkins

    Vostok 1

  • *****
  • Posts: 185
  • Joined: 22 Jan 2014

Posted 14 February 2024 - 06:18 PM

You may want to take a look at my article in the June, 2023 issue of the Astronomical League's Reflector magazine.

 

Downloadable from here:  https://www.astroleague.org/reflector/

 

I use a 102mm f/7 ED refractor for photometry of LPVs, nova, and a few Young Stellar Objects. I've found this instrument suitable for targets from about 8th magnitude down to 14th magnitude in V.  For brighter targets I use a medium focus camera lens mated with a CCD camera identical as used on the refractor.


  • Ed Wiley, Astrolog and Fernando Alonso Velez like this

#5 Xilman

Xilman

    Messenger

  • -----
  • Posts: 413
  • Joined: 26 Feb 2018
  • Loc: Cambridge UK & La Palma (MPC J22)

Posted 15 February 2024 - 04:00 PM

Recently, I begin to preparate an equipment thinkng to do photometry, and following the AVSSO tutorial is posible to do this even with a DSLR camera and small lenses, however I like use a refractor APO (~4') with a focal lenght about 700mm, but I wolud like to know about experiences doing photometry with this OTAs. Some question that I've are:
Is necesary an refractor APO? or acromatic is enogh?
Is a  6' RC a better option?
I thank your sugggestion and comments

Anything is fine. It's not how big it is that's important, it's what you do with it.

 

I started my VS observations with a 5mm (0.2 inch) refractor which had lousy chromatic aberration, astigmatism and didn't focus properly. The camera was unfiltered, uncooled and had a bad signal to noise ratio. It still made useful measurements.

 

It was a Mark-1 eyeball.

 

Learn to use what you have before investing serious money in other stuff. I am quite certain that you can make scientifically valuable measurements with a little education, care, and attention to detail.


  • Fernando Alonso Velez likes this

#6 jgraham

jgraham

    ISS

  • *****
  • Posts: 24,520
  • Joined: 02 Dec 2004
  • Loc: Miami Valley Astronomical Society

Posted 04 March 2024 - 10:38 AM

+1

Use what you have. I have used a wide variety of telescopes, mounts, and cameras and they have all worked well. I kinda like having about a 1 degree field of view, but even that is negotiable. I have used my RC8 with a Baader Mk III MPCC and a Canon EOS Ra and that worked well. I am currently testing a Seestar S50 and the initial results are very encouraging!

Enjoy!
  • Chunkles and gw_dra like 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





Also tagged with one or more of these keywords: Refractor, Equipment



Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics