can you 'undo' calibration in maxim dl ?

[graham.hobart (Graham stevens)]

Hi I cocked up and used the wrong folder to set up calibration frames recently and then said yes to save all the files - it appears I used the wrong flats and would like to go back and recalibrate these mono images.
Can I reverse this or have I irreversibly altered the data?
I tried resetting the computer clock back but this does not affect documents.
Help please would be greatly appreciated

Thanks
Graham

[Atmos (Colin)]

Theoretically if you use the Pixel Math part in MaximDL and multiply the affected framed by the bad flats it will add it back.
Anyone disagree with this?

[graham.hobart (Graham stevens)]

HI Col, sounds interesting- can you elucidate for a software moron (obviously!!) ?

[Atmos (Colin)]

Take some screen shots when I get home

[graham.hobart (Graham stevens)]

If I understand correctly- instead of dividing the flats from the lights you can open the light as image A in the pixel math and then open B the flat and AXB? - can only do one image at a time though? (light plus flat)
Is there a batch processing for this? (I'm at work so I just googled)
The other thing that may be possible is access previous versions in the shadow copy on hard drive in W7? ( googled that as well)

[rally]

Graham,

The troubles we create for ourselves.

Could be difficult !

A couple of questions
Did you (or MaxIm DL) include Darks and or Bias' in the calibration process
Did you use a Master flat or use multiple flats in the same directory - or just a single flat.


Good practice is to always keep an original copy of all your images and only work on copies of these, that way you can always go back to the beginning !
20/20 vision with hindsight is a wonderful thing !!

[graham.hobart (Graham stevens)]

Hi Rally- did darks bias and flats-= loaded them using calibration wizard so they are all in the programme as individual files- so I assume it creates masters off the bat first but has left the original files still intact, there is a button to press to use masters but I didn't check this as I was thiking about adding some further calibrations frames later.
I usually keep originals - but for some reason I decided to to tick yes for all and not no for all - maybe as I had a lot frames and it took so long to calibrate. Bummer - there goes 3 nights work!!

[rally]

Graham,

I would say that the complexity of working out exactly the correct process for getting the originals back might be more time consuming than reimaging.

This would however be a good exercise for a student of astrophotography to fully understand the process (as MaxIm does it) by reversing each step of the process in the correct order.
From what you have indicated there are quite a few steps in this process.

I dont think its impossible and probably well worth the mental exercise if you have plenty of time to waste ! - but not easy either.

Its been too long for me to recall what and how MaxIm does it - a lot depends on what you have in the directory and if MaxIm has automatically scaled the darks or not !
A lot of unknowns, how the pedestal was treated, what algorithm MaxIm used on the flats etc

If you got it sorted out - assuming the images are the same temp and same exposure time and all used the same Darks, Bias and Flats . . . a lot of "Ifs", then you could write one Pixel Maths formula and execute this on each image at a time - being careful to rename the original to the same name used in the formula and then rename the new image appropriately.
That need not necessarily be done in MaxIm by the way - you could use PI (assuming you inform PI of the appropriate file types)

What we need is the ISS CIS team to do the forensics for you !

Good luck with it - Who's game ?

Cheers

Rally

[graham.hobart (Graham stevens)]

Rally, I think I will just re image it next year mate!!!!