I've been kicking around taking some star/sky shots, something that I have never attempted before. I was curious which one of my lens would be my best bet and any other suggestions or tips you might be willing to offer.
I have:
nikon 18-55mm f/3.5-5.6G AF-S Dx
nikon AF-S DX Micro 40mm f/2.8G
nikon AF-P DX 70-300mm f/4.5-6.3G ed vr
You want the wide field of view. The wider the field of view... the easier (more forgiving) it will be as you acquire data (as you get used to how this is done, and if you have a tracking head, you can start to use narrower fields of view... but any movement (vibrations or alignment errors) will be more noticeable at narrower fields of view.
You want a moonless night (nights near the "new moon" phase ... just check the moon rise & set times to make sure that the hours you plan to shoot wont have the moon in the sky. The amount of light pollution created by the moon will wash out a lot of faint objects.)
You want to get away from urban light pollution and into dark skies.
Ideally... get a "tracking" head for your tripod. Sky Watcher's "Star Adventurer" and the iOptron "Sky Guider Pro" are popular ($300-400 price range). The idea here is that you adjust the angle of this tracking head so that it's axis of rotation is parallel to Earth's axis of rotation (in other words you point it toward the celestial pole). You can still point the camera in any direction you want. The idea is that as the Earth spins from West to East, the tracking head spins from East to West ... at exactly the same rate. So if these two axes are parallel, they cancel each other out. You can take extremely long exposures with no motion blur (I've done 8 minus exposures ... no problem.)
To take exposures longer than 30 seconds... you probably need a remote shutter release (ideally get an "intervalometer"). Depending on your camera, there may be computer apps that can control the camera to do image acquisition (e.g. "Backyard NIK" is compatible with many (but not all) Nikon models. This is software specifically designed for astrophotography image acquisition. You can pre-sequence your entire capture run and let it do the work (some guys go take a nap if they set up a capture run that will take hours to complete)).
This is far from complete ... but I did this last Saturday night (this is 20 x 4-minute exposures stacked). It still needs a lot of work (I also shot 20 x 60 sec and 20 x 10 sec exposures so I build an HDR and not blow out the core of the nebula. I have not yet integrated the other shots to build the HDR). And it needs some work with color (it was shot through a light pollution filter in an urban location... so colors are a bit whacked out) and needs a bit of deconvolution and I need to shrink the stars (processing typically takes longer than capturing the data). I also need to work on neutralizing the background color casts... if you check closely you'll see an orange/red cast in the "black" background of space near the top half of the image... and a blue/green cast on the bottom half of the frame... thank you urban light pollution <sigh> (yet another reason to get away from the city).
All-in-all it was nearly 2 hours of exposure time to get all the "light" sub-exposure frames. (There is also about 1 hours worth of "dark" flames, plus flats and bias frames.)
This was shot through a 480mm apochromatic telescope.
View attachment 167724
Here's one I shot a couple years ago ... but this one was shot using a 135mm lens (camera on a tracking head). This one is also a bit more true to correct colors.
View attachment 167725
This one was much easier to process. I captured this while in "Science City" (this is the area in Maui on top of the Haleakala Volcano where the professional observatories are located. There is a national park, but the area I was in is closed to the public. I only had access because I was the guest of another astronomer.) As such... there was NO light pollution of any kind, no filters were needed, and hence it's truer to correct colors and did not need an obnoxious amount of post processing.
Clear Skies,
Tim