Only one Frame

[johnst]

So, the other night when it was really clear I managed to image the Horsehead Nebula with 22 lights at 800 iso and then did darks, then I got carried away and took 22 lights of the Leo triplet but used the same darks. When it came to loading on the laptop I realized that I used 2 cards and got my flats and darks mixed up. Now I have got a message on DSS saying 'Only one frame (out of 23) will be stacked. You should check/change the star detection threshold to detect more stars & help DSS find a transformation between the reference frame & the others' 

I guess that you don't 'share' darks and also keep to one subject especially as I'm still learning.

Thoughts please anyone.

John  

[david_taurus83]

You can use the same darks for both sets of lights as long as all 3 are the same exposure length and ISO. Assuming you didn't move the camera between switching from Horsehead to Leo you can also use the same set of flats. 

[The Lazy Astronomer]

Your issue sounds like DSS hasn't found enough stars to stack the frames. It needs a minimum of 8 stars common to all frames in order to align them. Try lowering the star detection threshold and/or trying to stack without any calibration frames (in case those are introducing more problems than they are solving).

As a side note, don't do darks with a DSLR, dither between lights and use bias frames - darks are only of use if you can control sensor temperature (i.e. with a cooler)