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

Taking Flats with a 294MC

  • Please log in to reply
3 replies to this topic

#1 rishigarrod

rishigarrod

    Sputnik

  • -----
  • topic starter
  • Posts: 31
  • Joined: 22 Jan 2019

Posted 23 September 2019 - 12:32 PM

Hi All

 

I have just started using a 294MC instead of a DSLR.

 

I used to take my flats using the AV mode of the DSLR and that worked perfectly. I have a flat field generator that produces a nice even light source.

 

I have understood that I should use at least 4 second exposure for my flats with the 294MC. I have turned my flat field generator down to a minimum but it is still too much. In order to dim it further I could use a tee-shirt or a piece of paper. Which would give me the best flats?

 

Cheers

 

Rishi



#2 descott12

descott12

    Apollo

  • -----
  • Posts: 1059
  • Joined: 28 Sep 2018
  • Loc: Charlotte, NC

Posted 23 September 2019 - 12:52 PM

I am not sure what capture program  you are using but SharpCap has a really nice flat wizard that allows you to adjust the exposure settings while viewing the histogram. You should try that and see how they turn out.


  • rishigarrod likes this

#3 rishigarrod

rishigarrod

    Sputnik

  • -----
  • topic starter
  • Posts: 31
  • Joined: 22 Jan 2019

Posted 23 September 2019 - 01:11 PM

I am using the Ekos suite to capture the images. No flat wizard but a nice preview mode with a histogram.

Currently I am trying to ensure that all 3 spikes are within the total range without any clipping.

 

My concern with using a piece of paper or t-shirt is that the flat will contain some of the structure but maybe I am getting concerned unnecessarily because the focus is at infinity? 

 

Looks like 2 pieces of standard weight A4 lets me take a 4 second exposure with a reasonable histogram and I can see my dust bunnies on the flat


Edited by rishigarrod, 23 September 2019 - 01:15 PM.

  • jdupton likes this

#4 jerahian

jerahian

    Viking 1

  • *****
  • Posts: 619
  • Joined: 02 Aug 2018
  • Loc: Maine

Posted 23 September 2019 - 01:14 PM

I am using the Ekos suite to capture the images. No flat wizard but a nice preview mode with a histogram.

Currently I am trying to ensure that all 3 spikes are within the total range without any clipping.

 

My concern with using a piece of paper or t-shirt is that the flat will contain some of the structure but maybe I am getting concerned unnecessarily because the focus is at infinity? 

Correct, no need for concern.  The dust motes and particles close to the sensor are the ones your are most interested in ironing out.  Any small particles on the paper or t-shirt should be of no concern.


  • jdupton and rishigarrod 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






Cloudy Nights LLC
Cloudy Nights Sponsor: Astronomics