Using MaximDL in conjunction with "Optimum Exposures Calculator"

[SlimPaling]

Hi ...

 

Can anybody help me with this as I am having trouble understanding?

 

I recently came across the "Optimum Exposures Calculator" on the Gibraltar Astronomical Societies web page and thought that it might help me find the best exposure setting for my CCD camera. The calculator is used in conjunction with several other processing programs ... including MaximDL to get information from actual iamges that have already been taken.

 

The same web page gives some detailed instructions on how to use this spreadsheet in conjuction with the "other" processing software ... but there is one section that I am having difficulty understanding how to carry out. This section is and follows ....

 

" Open a calibrated test exposure in your choice of software (e.g. MaxIm DL, ImageJ, PixInsight, etc) and create a preview box over a decently-sized area of the image that is purely background (no stars, no nebulosity, no galaxies, etc - just background). You may want to create a number of these preview boxes to average your results. Determine the Median 16-bit pixel value (ADU) of the preview box region of your image. This is your background ADU and should be entered into Background Flux Median in the Base Image Statistics section of the calculator. Next, enter the exposure length of your test exposure in minutes."

 

Can anybody explain, in easy stages, how this is actually carried out in Maxim??? I have spent quite a bit of time on this and have failed to do it :-(((

 

Mike

[BlueAstra]

I tried this with MaximDL:

Open image in MaximDL, Open 'Information' window. Select 'Aperture'. Should see circular cursor over image. Double click on region of background. Rings turn yellow. Right-click on rings to get context menu. Play with 'large rings', 'increase aperture', 'increase annulus' to get reasonable size aperture on background. Look at median value in display. Check out the help file for the information box. I think the numbers are in ADU but not absolutely certain.

Graham

 

[steppenwolf]

2 hours ago, BlueAstra said:

I think the numbers are in ADU but not absolutely certain.

I believe that they are ADU units and Graham is spot on in his workflow!

[SlimPaling]

Many thanks Graham & Steve .... I will take things further now ?

Cheers Mike