This was an experiment. I was out a couple of weeks ago shooting the Milky Way at a new location. While there, I decided to try something different with my backup K5 and Tak 85/f1.8. I set it up to shoot 3 second exposures (maintaining stars as a pin point) and let the earth's rotation rotate the sky across the front of the lens, then stack the images. I just set it up and let it shoot for a couple of hours. So, here is the resulting image (K5, 85mm, ISO 800, f1.8, 3 sec - 1374 images stacked). For me this is probably going to be as deep sky as I get.


The Milky Way core is to the left and down. I miss estimated where I was pointing, so didn't really achieve the area that I wanted to shoot, but it was a good learning experience. Next time, I think I can go to ISO 400, do a better job in pointing and perhaps go to 4 seconds. I used 3 seconds to maintain the stars within a 4 pixel box, which may be a bit too tight.

I used the software that Pete_XL suggested for stacking Sequator - it took 30 minutes and worked out well.

• Does anybody know the software sequator? - Astrophotography - PentaxForums.com

Does anyone have a good web site that locates the part of the sky I actually shot?

Cool experiment.

For determining pointing, you're looking for:

Astrometry.net

Use the web client, upload your photo, and it'll give you a solution.

It's amazing how many stars made it into your shot. Just thinking of my shots with a similar field of view, I think after 30 minutes most the stars had left the frame, is the result cropped down to the areas with full overlap?

I just tried the stacking software, and this is the result. So, I really don't know if this is just the full overlap or what... - I figured it out. The lens shoots 19 x 16 degrees and the image is 16 x 10.6 degrees, so it appears to be just the full overlap.

Here is the solution from astrometry.net
Astrometry.net


I was trying to shoot something more like this.... which would be with a wider lens, but I went with the 85mm because it had the largest physical aperture.

As jeff said - use astrometry.net. Here is what you have in your image:








There is lots of nebulosity around Antares. Perhaps you can dig work it out as you have an hour of light captured .
But maybe it is difficult or impossible because of the short length of you Subs.
Impressive that the software handled 1,300+ Subs in 30 minutes!

Cheers
Pete

Ooops - you were faster

I just started playing with it earlier this afternoon - mainly to start learning about the Sequator software utility. Right before I had to leave for the airport to pick up my son, I decided I would post this just for grins. I have a little over an hour, but the subs were very short, since I was not tracking - they needed to be short to prevent trailing. My PC is somewhat beefy - i7, 4 cores, 16GB ram. The stacking software you ran across, just trudged through it without any problem.

I really wanted to mosaic the frames, but a full overlap is probably better overall.

I do think that I will try to keep shooting two systems - one for landscape and one for star fields when I go out. This way, I get a little bit of both.