Glare in my first moon shots

[Andremz1]

Hello All, 

Recently I got a telescope as a Christmas gift (Celestron 8se) and I am a beginner in both telescope world and astrophotography. I bought a Canon T6i several weeks ago and took some moon photos couple of days ago using 2x barlow and my camera in manual mode with low ISO and 1/125 shutter speed. Took me almost 20 shots before I figured out how to get the photos focused with correct exposure. The thing that I start noticing was  a certain glare/light in the middle of the photos. Can anyone tell me what that is and how to correct that? See attached photos. Thank you so much

[Owmuchonomy]

Do you get the glare problem if you image without the Barlow?

[celestron8g8]

Definitely internal glare . 

[ollypenrice]

The 8SE has a native focal length of 2 metres so I'd start without the Barlow. Focus will need a lot of patience. Also, make your last adjustment to focus in an anti-clockwise direction so that you are pushing the mirror up the tube. If you do it in a clockwise direction the mirror may continue to settle down the tube after you've stopped turning the knob.

The glare may well arise from the Barlow.

Olly

[Andremz1]

On 08/04/2018 at 11:35, Owmuchonomy said:

Do you get the glare problem if you image without the Barlow?

Hi Chris,

Sorry for the late response. No, when I remove the 2x Barlow the moon shots don't have that same glare. They are all good. I tried last night again and I even used different size of extensions between Barlow and DSLR (Canon 6xi), and still the moon pics had that damn glare. I think it is the Barlow, but then again when the same Barlow attached to eyepiece, there is no problem. The problem shows up on when I attach a DSLR. It has been a frustrating  experience. 

 

Thank you for you time and feedback.

 

Andre

[cjdawson]

from your description the glare is definitely light bouncing between the barlow and the sensor.

If you remove the glass from the barlow (don't do it)  the glare would dissappear, put it back and you'll get the glare back.

The way to solve this, if you really want to use a barlow is to use a different barlow.  I've got a couple of them, a short tube, and a long tube.  This changes how the barlow brings light together.  There's also another thing that the spacing between the barlow and the camera sensor is important.  If it's wrong, you'll get artifacts in your image, like the glare that you are talking about.   Maybe try an extention tube between the barlow and the camera sensor?

[Stu Wilson]

Also if you use the Canon software to grab a video and stack in Registax or something alike you could try ditching the Barlow and use the available 5x magnification within the software.

I've used this feature on moon shots lots of times with very good results.

Clear skies

Stu

[cjdawson]

If you use BackyardEOS, they say to put the camera into liveview, then zoom that to 5x, as that's pixel for pixel!

[newbie alert]

As suggested don't use the barlow..id recommend a planetary camera thou .. opens up a new world in imaging..moon mosaics..other planets on a bigger image scale..you won't go back to your dslr