Jump to content

Banner.jpg.b83b14cd4142fe10848741bb2a14c66b.jpg

Something obstructing view


Recommended Posts

The Moon images look over-exposed and the focus is not good. 

I suggest some research on the advanced controls for your smartphone's camera. Can you manually control the focus or exposure? Can you lock it at focus on infinity?

Note that the size of the Moon is about 1800 arcseconds and the size of Venus (at present) is 41 arcseconds.  

Link to comment
Share on other sites

18 minutes ago, phantomgod_06 said:

But I still don't understand how to not get the secondary vane when observing 

You must still be out of focus. The secondary essentially disappears when the target is in focus, you should just see bright diffraction spikes (four of them) coming off the target, most noticeable on bright stars. If you still see the dark shadow of the secondary then you are well out of focus.

You could try focussing on a bright star, you are in focus when the star is at its smallest/tightest. Just to echo the point from earlier, if you are in focus for the Moon then you will be in focus for Venus and other targets, you may just need a small tweak on the focuser but won’t be wildly out.

Link to comment
Share on other sites

Did you use the same eyepiece for Moon and Venus? 

If you changed eyepieces it could well mean focus needs adjusting. But if the Moon is crisp and you can see sharp craters you should also see a sharp Venus if you change nothing besides what the Moon is pointing at. In fact if Im struggling to focus on something like Mars that being a small fuzzy ball can be tricky to focus,  I will first point at a nearby star and get that sharp. 

If I defocus significantly on a bright star I get a similar image to your first image with my 150mm four vane reflector.

As noted above, what your eye focuses correctly is key, your phone could be looking at anything in the tube and trying to focus on it.

Link to comment
Share on other sites

What eyepiece are you using? I it’s like a stock eyepiece (one that came with the telescope when you bought it) depending on what type it is sometimes they can provide a good visual but be impossible to take a photo through.  If it’s not that try adjusting the distance of the camera from the eyepiece and also adjusting the exposure it looks like both of those are possibly off, though I would adjust your exposure settings first and then adjust the backfocus

Link to comment
Share on other sites

To backup what has been said.

If Venus is in focus when you look down into the eyepiece.

Then the autofocus on the camera is failing to find the tiny dot that is Venus, and has latched onto a much bigger and closer object, the secondary.

As Geoff suggested, try to lock the phone's focus onto a fixed focus setting.

And a phone holder if you're going to continue using the phone.

Michael

  • Like 1
Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.