Initial Scope set-up / alignment

[Aramcheck]

Hi,

We've recently upgraded from an EQ2 to an EQ6 with GOTO & have bought our first DLSR. So far we've only used the new scope for visual observation, but I'm hoping to have a first go tonight with the DLSR.

Should I set attach the DLSR to the OTA straight away, or do I need to do the 3-star alignment process first with an eye-piece & then replace/fit the DLSR and re-balance?

I'm guessing it would be best to have the DLSR already fitted, before doing the alignment & to use the live view to fine-tune the 3-star alignment?

Many thanks

Ivor

[don4l]

1 hour ago, Aramcheck said:

Hi,

We've recently upgraded from an EQ2 to an EQ6 with GOTO & have bought our first DLSR. So far we've only used the new scope for visual observation, but I'm hoping to have a first go tonight with the DLSR.

Should I set attach the DLSR to the OTA straight away, or do I need to do the 3-star alignment process first with an eye-piece & then replace/fit the DLSR and re-balance?

I'm guessing it would be best to have the DLSR already fitted, before doing the alignment & to use the live view to fine-tune the 3-star alignment?

Many thanks

Ivor

I wouldn't worry about rebalancing at this stage.   My EQ6 isn't half as sensitive to balance as many other  mounts.

 

If you are happy doing the alignment using an eyepiece, then do it that way first.

The first problem with the camera will be finding focus.  To get the camera into focus you will probably need to move inwards from where the eyepiece was.  However, if you are removing a diagonal to fit the camera, then you will probably have already moved in too far.

The first time that I tried to find focus, I was so far off that I had no idea if there were any stars in the field at all.  For me, the thing that helped was to make absolutely certain that I could trust the finder scope.  Before putting the camera on, I would align the finder so that I could use it to put a bright star in the centre of a high powered eyepiece.

Once you know where the focus is, then aligning with the camera is likely to be more accurate.

 

[rockinrome]

Hello!
To start I would use the eyepiece and then connect the camera afterwards.
Use a Bhatinov mask to obtain exact focus - a must for astro photography.
So...

1. Polar align
2. Mount and balance scope with eyepiece (without Bhatinov mask)
3. Do star-align, making sure the last star you go to is "roughly" in the area of your image target
(Mount will start to track at this stage)
4. CAREFULLY remove eyepiece and attach the camera and use the last align star with the Bhatinov mask to focus the camera. Using Live View is helpful, but I would just take (say) a 10 second exposure at ISO3200.
5. Carefully adjust focus to obtain the tell-tale diffraction spikes
6. Remove Bhatinov mask and slew to image target
7. Do a test exposure like in (4) to make sure the image target is framed correctly.
8. Make a brew
9. Start Imaging

Clear skies
MJ

Edited October 1, 2019 by rockinrome

[CedricTheBrave]

also depends if you are going to control the camera from a laptop.

i found that aligning with an eyepiece  gave a slightly different position when i attached the camera also you may need to re-balance a little with the camera attached.

 

[DougM43]

Personally I would balance everything and use the finder to do your star alignment, obviously that would need to be aligned with the telescope correctly first, there’s a good chance your first alignment star could be quite a way off so the wide angle of the finder is quite helpful. It’s the way I do it and seems to work fine.

[Ouroboros]

8 minutes ago, DougM43 said:

Personally I would balance everything and use the finder to do your star alignment, obviously that would need to be aligned with the telescope correctly first, there’s a good chance your first alignment star could be quite a way off so the wide angle of the finder is quite helpful. It’s the way I do it and seems to work fine.

Yes, same here. I balance up first with camera attached even if I subsequently replace it with my eyepeice to do the three star alignment.  I nearly always find I have to adjust the pointing of the finder to that of my eyepeice or camera. This is easily done by pointing the scope at a bright star. 

One hint if using the DSLR camera at the scope for the first time .... it's worth setting a delay of 10s before the shutter opens to allow any vibration to dissipate after pressing the shutter button. Or use a cable release if you have one. 

 

[Aramcheck]

Thanks everyone - responses much appreciated!