More Craters on 1st attempt

7 frames stacked

Top Craters w/ Webcam

Another from a first attempt.

1st attempt with Phillips 900SPC

Still learning but it is a start: 56 frames that were graded "A" out of 1800; calibrated and stacked in Images Plus 2.82

Mistakes made:

320 x 240 resolution. SPC900NC not recognized in Craterlet so I could not choose 640 x 480

Background Subtraction Tool

As recommended in Jerry Lodgruss' book, there is a very good Java based Background subtraction tool that does a very nice job on minor uneven field illumination for JPEGs (Tiff not supported.) Simple to use; puts output into Photoshop format.

Before Background Subtraction Tool



After Background Subtraction Tool



It can be downloaded for free!

Combatting Vignetting

If you are at all familiar with SCTs you probably know getting a flat field is not easy due to Coma when adding a Focal Reducer. I don't doubt that taking a flat field is the best way to offset the problem. Right now, the vignetting is so severe, it is not possible to subtract it via software.

So I'm making an attempt with some equipment to help too. Classic SCTs don't have a 2" opening for the diagonal. I've got a Peterson 2" adapter and now I've purchased a ScopeStuff "True 2" Barrel to Canon EOS Adapter" Here's the blurb from the page:

These adapters attach to the front of SLR cameras and have 2" barrels
that fit in focusers and other accessories. The barrels provide an
unobstructed 1.75" (44.5mm) opening, and are threaded for 2" filters.

I like the idea of being able to use the 2" filters along with this adapter. So I'll experiment without the Focal Reducer in the train as well as with.

M42 in Ha False Color

Playful image in Hydrogen alpha false color