Astrozoid

I guess we will have to agree to disagree on how truly dark an east coast, sea level, high humidity, surrounded by major light pollution in Philadelphia, Tom's River, and Atlantic City mag 20.5 ...

Well, if you call mag 20.5 dark, I guess so. I don't think that is particularly dark when I compare it to the mag 21.8 sites I've been to. Jerry

20.81 is in the Pine Barrens of New Jersey. That's about as good as it gets anywhere near me. Colors on the light pollution map reference how dark the sky is in that location. Click on overlay ...

Hi Mark, That's pretty nice next to the clusters. Jerry

Hi Stan, Ok, here's my shot of the integrated flux nebula around M81 and M82. Taken with crappy old DSLRs. Lets see yours. In color. Jerry

I don't really see any vertical dark lines in the image. I see some horizontal issues with what looks like incorrect flat fielding. Depending on how dark your sky was, 32 minutes may not be enough ...

The standard scale for the brightness of astronomical objects (like stars) and measurements of the night sky in magnitudes per square arcsecond. A magnitude 18.5 sky is like having a star of that ...

Roger, it looks like you have oversaturated the core of the nebula and lost tonal definition and separation in the pillars of creation. And there is some blue reflection nebulosity in there to the ...

Hi Mark,  I can get extremely accurate polar alignment in a couple of minutes with the Astro-Physics RPAS on the Mach1 mount.  Of course, I did drift align when I first got the mount, and then ...

Hi Rudy, Thank you! I really appreciate your kind words. Jerry

There' just too many variables to directly compare the two images on a specific basis. The comparison is really intended to be much more general looking at what you can get at a dark sky site in a ...

Using a laptop at the scope is not that big of a deal once you get past the learning curve, and it will give you more flexibility. You want to take your astrophotography to the next level.  Like ...

Here's a single 30-minute frame of M31, the Andromeda Galaxy shot with a Nikon D810a. Click on the link for more technical information. This was also shot on a night in July when the ambient ...

Yes, that's correct. And you can work it backwards for camera lenses where they only specify the focal length and focal ratio to determine the aperture. Say you have a 200mm f/2.8 lens... 200/2.8 = ...

Hi Marco, Yes, in my book on astronomical image processing for beginners, I use DeepSkyStacker for aligning and stacking, and then take the image into Photoshop for removing sky glow and light ...

Thanks! I can sympathize! Jerry

Thanks!

Thanks! You should have tried putting a single cut gas-hypersensitized film frame into a cold camera in a changing bag, and then totally defrosting the camera and warming it up to put the next cut ...

Yes, that should be pretty dark... :-) Except for the mystery Marfa lights... :-) You should get some good results from there. Jerry

No, F/6.5 is f/6.5 no matter on a telescope or a camera lens. Of course, like everything else, it's actually more complicated than that because T stops are what really matter, but for a beginner, ...