Focusing with DSLR

[xanthic]

I've taken a few shots with my camera (lunar and solar). I don't seem to be able to get the focus quite right. Does anyone have any tips?

[dawson]

Turn the knobs marked "focus"; i find that helps

Jd

[Perkil8r]

Are you using the 150p newt?

 

If so there are two methods you can use.

 

1, buy a Bahtinov mask. They cost around £15 and will make focusing a piece of cake. You use them to focus on a bright star (not a planet though) and when the pattern becomes symmetrical you are at focus.

 

2, if using the 150p newt there is a trick. Pick a nice bright star, say Vega. Take about a 30 sec exp. The spider in the newt should cause a diffraction spike pattern in the form of a cross. Sticking with the 30 sec exposure time, adjust focus until you get the longest thinnest lines you can get. That will be a cheap way, not great and not 100% accurate but close.

 

Once focused by either of these two methods you should be pretty close for the moon and sun. I focus mine in this sort of way and lock it off before slewing to the target, in the case of the sun I leave it locked in position from the previous night and keep my fingers crossed.

 

If you are specifically going fr the moon or sun, try and pick a star close to the moon to focus with, with the sun try and pick one somewhere where you think the sun will be when you intend on focusing. If you're not sure about that, use one say 50 degrees elevation and due south. The reason being that the atmosphere acts a bit like a weak lens, therefore focus may alter slightly between a low down object and one higher up.

[dawson]

Leigh, you have a Canon, so have a look at se software called BackyardEOS; Ron showed me this when i went for my introduction to astronomy session at his. It allows you to see the image in live view on the laptop and also has a focus help which you could use. You can also set up how many subs etc you want to do with that software. I used it for the few solar images i've attempted so far, but my camera kept shutting down which i never got to the bottom of so i've not done any more since. Doing it that way also allows you to look at your images in a more shaded area if say imaging the sun (as long as you've got an active usb extension for the camera (i've got some if you want to borrow one)).

James

[+Graham]

Leigh, you have a Canon, so have a look at se software called BackyardEOS; Ron showed me this when i went for my introduction to astronomy session at his. It allows you to see the image in live view on the laptop and also has a focus help which you could use. You can also set up how many subs etc you want to do with that software. I used it for the few solar images i've attempted so far, but my camera kept shutting down which i never got to the bottom of so i've not done any more since. Doing it that way also allows you to look at your images in a more shaded area if say imaging the sun (as long as you've got an active usb extension for the camera (i've got some if you want to borrow one)).

James

 

 

James I had exactly the same problem with the camera shutting down.

I did get to the bottom of it and have cured the problem.

I found out through a trial and error process that it was being caused by the auto update part of Adobe reader program.

When I image with the canon and BYE I make sure the computer is not connected to the interweb and ALL auto updates are turned off.

Problem solved.

[xanthic]

Thanks all. That's given me plenty to consider (It also reminds me why I despise Windows so much)

[dawson]

"(It also reminds me why I despise Windows so much)"

 

You still need to come and sort my Windows-related issues out.... Hahah

[xanthic]

Also I think using a prime EP instead of my zoom will probably help. It never stops, does it?

[dawson]

You can borrow one of mine and the ring to attach a Canon if you want tonight.

 

James

[Guest]

Leigh, you have a Canon, so have a look at se software called BackyardEOS; Ron showed me this when i went for my introduction to astronomy session at his. It allows you to see the image in live view on the laptop and also has a focus help which you could use. You can also set up how many subs etc you want to do with that software. I used it for the few solar images i've attempted so far, but my camera kept shutting down which i never got to the bottom of so i've not done any more since. Doing it that way also allows you to look at your images in a more shaded area if say imaging the sun (as long as you've got an active usb extension for the camera (i've got some if you want to borrow one)).

James

Is Backyard EOS free and, if so, does it work with other cameras, such as Minolta?