dyximan

I am looking for advice on how to find the North Star,Milky Way, and other constellation for photographing, And not being all that Knowledgeable in this area I understand the milky way is only visible in the Northern Hemisphere part of the year yes? I live in Other California Also suggestion and advice on how to shoot the star trails a the world turns looking at the North Star time lapse length of time to open shutter and frequency etc.
Thank You

JimH123 Loc: Morgan Hill, CA

A good app that I found is called Mobile Observatory. There is a free version, and a few dollar Pro version. This app provides lots of aids such as best objects tonight, and many others. I use it with an Android tablet. Don't know if it has been ported to iPhone.

Another useful one is Stellarium. It actually provides more stars than the previous app., and I go to it when this is important to me.

There are more than these if you look.

Europa Loc: West Hills, CA

For a iPhone app, I use Sky Safari.

For star trails, it depends on your sky/light pollution. I shoot 20-30 seconds, with a delay long enough to download the image. shoot until the sun comes up. If you are pointing at the north celestial pole, you get partial circles, but you don’t have to point at the NCP, you can point other directions for arc type streaks.

The Milky Way is not a winter object.

Fstop12 Loc: Kentucky

I use the Photopills app to plan my night shots. It's a very impressive app. Something to think about before you embark upon shooting Star Trails. It's time and labor and weather intensive! As someone else suggested, shoot all night. I have achieved some pretty decent star trail RAW images in 3 hours. The work begins in Post editing, getting rid of plane trails that come through during your shoot, stacking images, tweaking etc. It can take hours. The results can be rewarding. I shoot with a Nikon D7000, Tokina 11-16 2.8.
using a remote timed shutter release. Usually 30 sec exposures @ F4. FYI, know your weather conditions and moon phase. Nothing worse than driving to a site, setting up, and then 1 hr into your shoot, the clouds start rolling in or a big full moon rises right up in your field of view. I hope I haven't discouraged you. I love shooting startrails. The more you do, the better you get at it. Here are the apps I use for planning. https://www.photopills.com/ for Clear Skies forecast. https://apps.apple.com/us/app/clear-outside/id921555752 Good luck and hope to see your results here in the hog.

juan_uy Loc: Uruguay

I do almost this.
With D7200 instead, all the rest the same.

tomad Loc: North Carolina

I use photopils. Works great.

SonnyE Loc: Communist California, USA

I've use Stellarium for years now. It's free and constantly under refinement.
You can use it a lot of ways, to learn where things are, and to control a mount and telescope. (which I realize is beyond your needs right now.)
It looks scary at first. But there are a lot of tutorials on it, and on how to set it up to search with it.
It's menu's pop up from the bottom, or in from the left side.
But it is fun to just use your mouse and mouse wheel to zoom in and out, or browse around the night sky anytime.

https://stellarium.org/

JimH123 Loc: Morgan Hill, CA

Here is a review on the "Mobile Observatory".

https://www.commonsensemedia.org/app-reviews/mobile-observatory

A few screen shots are shown. But there are a lot more. I use this app first since it is so plain and easy to understand. When I want to see even dimmer stars, I switch to Stellarium or SkySafari. But this one is so well designed, that it is a no brainer to find one's way around the sky.

Here is a youtube review also:

https://www.bing.com/videos/search?q=mobile+observatory+app&view=detail&mid=CF1D6CAF17B12060FA7FCF1D6CAF17B12060FA7F&FORM=VIRE