2 replies to this topic

[WoogsNuts]

Hey everyone. Apologies if I didn't reply to my last post. I ended up going in a different direction and saying 'to hell with my budget' lol.

For my first astrophotography rig, I've purchased the following:

Canon D90

Canon 300mm F4 L IS

Sigma art 18-35mm f1.8

I know prime lenses are preferred but, felt this will still be very nice and more dynamic than a fixed focal length.

Eqm35 mount plus dove tail slide

I know this will sound silly but, this should all just slap together, right? Haha. I'm just trying to make sure I have everything I need, so I can no-life my new hobby and rig when it shows up.

Are there any other small pieces of kit that you might recommended? Any phone apps you would recommend as quality of life improvements?

Thank you so much for your help and time, I'm getting excited🙃

[alanturner]

Other needs?

1) power for the mount?

2) camera control: intervalometer, snap port or other computer + software?

[EPinNC]

To alanturner's list, I'll add:

 

3) focusing method

 

These are mostly about technique rather than special equipment, but there is one piece of gear that can help.

 

Focusing a conventional camera lens on the sky and getting pinpoint stars can be a surprisingly difficult task.  There are at least 5 different concerns here:

 

a) Autofocus likely will not work.

 

b) In the old days, camera lenses had hard stops at infinity focus.  Many current lenses can focus "beyond" infinity.  So, you'll still need precise control.

 

c) You probably aren't going to be able to look through a viewfinder, so you'll be using the rear display.  While you can probably zoom in on the rear display, it will still be difficult to judge whether a star is focused to its sharpest possible state.  A strong magnifying glass will likely help.  A suitable "Bahtinov mask" that goes over the front of the lens can help you achieve sharp focus better than your eyes.

 

d) Periodic re-focusing can be necessary.  Glass and metal change shape as they change temperature, and you can lose that sharp focus you got at the beginning.  (This is true of telescopes too.)

 

e) Beware of "zoom creep" in zoom lenses.  Some zoom lenses are susceptible to sinking back into the lens body when pointed upward.  If that's a problem for you, a piece of painter's tape can help stabilize the zoom setting once you have it set the way you want.

Edited by EPinNC, 04 November 2024 - 02:52 PM.