Got abit of clear sky down here in melbourne for a few hours only at 6:00pm so I decided to take a few pics of NGC1977. 18 x 84 second stacked in registax. processed in photoshop cs2. darks autosubtracted.
Took many shots refocusing but the diff spikes are just like that?
Those diffraction spikes are weird though. There is a little evidence of them on your Keyhole shot and your Triffid shot, but nothing like this. What type of spider is on your scope? If it is the normal 4 vane, then it is not causing these spikes. They look more like spikes caused by a hexagonal iris on the camera.
thanks for the replies guys. I'm not quite sure what causes the diff spikes to look like that. I have only 3 spider vain on my scope. From what i read before, 3 vain = 6 spikes, 4 = 4 spikes. At first, i thought it was my focusing which causes the spikes to spread, i then adjust the focus and took another shot which looks exactly the same. Did this a few times no idea maybe dew?
That would be it, a 3 vane spider caused 6 diffraction spikes. I get that with my 8" f7 scope, which also has 3 vanes. Mainly see it on Bright to semi bright stars. I like em, they look better than the 4 spikes in my opinion
thanks andrew. wonder how the stars look like with the "S" shape curve spiders.
