Dslr Or Telescope Focus?

[stargazer16]

I got out my old telescope from the attic.  my interest is to get my dslr connected to my telescope in hope to get a better picture of moon then my 210mm lens on my camera ( telescope is Tasco f=700mm d=76mm ) .

This may be a dumb question. But when i have it all connected and i have the moon in view which does the focusing on the moon , the camera or telescope?

[RichM63]

Actually it will be you. You will have to use the camera on manual mode and you then physically focus the telescope in the same manner as if you were using an EP for viewing.

or, as you should already be doing manually with your 210mm lens.

(PS, sadly even if you get things hooked up, I'm not convinced that the illustrated device will handle any of the weight of a DSLR)

Rich

[stargazer16]

so the focusing will be done by me on the telescope not the camera

[Cornelius Varley]

If you are connecting a DSLR body to the telescope then you adjust the focussing on the telescope. Please be aware that with this form of imaging (camera body attached to focuser) you might not be able to achieve focus, you might need to use a barlow lens in the imaging path to do this.

[LukeSkywatcher]

Hmmm!!!!!!!. Maybe this is where ive been going wrong. Whenever i've attached a DSLR to a scope (very rarely). I normally adjust the focus only on the camera. I dont recall ever having to adjust the focus on the scope. I get sharp images non the less.

If i do any imaging.......its only ever widefield of constellations. 

P.S.~I agree. I dont think the scope/tripod in the opening post could take the weight of a DSLR.

I may be wrong here, but that mount is a German EQ mount. The scope tube to me looks like its the wrong way round.

I'm not seeing any slo-mo controls, so maybe i'm totally wrong and its an Alt-Az. Tube still looks the wrong way round to me.

[Cornelius Varley]

Hmmm!!!!!!!. Maybe this is where ive been going wrong. Whenever i've attached a DSLR to a scope (very rarely). I normally adjust the focus only on the camera. I dont recall ever having to adjust the focus on the scope. I get sharp images non the less.

If i do any imaging.......its only ever widefield of constellations. 

P.S.~I agree. I dont think the scope/tripod in the opening post could take the weight of a DSLR.

I may be wrong here, but that mount is a German EQ mount. The scope tube to me looks like its the wrong way round.

I'm not seeing any slo-mo controls, so maybe i'm totally wrong and its an Alt-Az. Tube still looks the wrong way round to me.

If you connect a dslr body to your telescope how can you focus the camera ?

The mount is an alt az and the telescope is mounted the right way round. If the telescope was mounted the other way around in the yoke you wouldn't be able to point the telescope at the zenith.

[LukeSkywatcher]

If you connect a dslr body to your telescope how can you focus the camera ?

The mount is an alt az and the telescope is mounted the right way round. If the telescope was mounted the other way around in the yoke you wouldn't be able to point the telescope at the zenith.

Ive only ever attached the DSLR to my 70mm refrac . Ive focused using the live view. Honestly cant say i have focused the scope.

[Uranium235]

As Peter mentioned, you will probably need to use a barlow to get focus. If it has a 1.25" focuser (which it looks like it has), you will encounter a fair bit of vignetting (darkening of the corners) in your images - so you will probably end up cropping the image.

If you have one, use a remote shutter release so you dont have to touch the camera when taking a pic (touching the camera is a bit of a no-no, whatever type of AP you do).

[Hackleby]

The biggest problem you will have with astrophotography or even just viewing on this set up is going to be the mount and tripod. I would strongly recommend that these be upgraded to enhance your experience. I converted the same scope for my son last year using a pair of 90mm tube rings that I picked up off of ebay for £5 and a spare dove tail bar. The scope now fits straight onto my old EQ5 that I handed down to him but will also fit a wide variety of other mounts. 

The focus tube is 1.25" and would require both a T ring and adaptor to enable a DSLR to be connected. I have not tried to obtain focus with a DSLR on this scope mainly due to the fact that I wouldn't trust the build quality of the focus tube with my camera.

[happy-kat]

A webcam would be very light and would allow you to create great images of the Moon, suitable webcams can be picked up for under £10. I bought one for £5 it works connected to my android tablet. I can create videos on that and then push then to the pc to process.

[RichM63]

Ive only ever attached the DSLR to my 70mm refrac . Ive focused using the live view. Honestly cant say i have focused the scope.

To avoid any possible confusion. A telescope does not contain any Autofocus or Electronic Focusing mechanisms that could work in the same way as a modern lens when directly attached to a camera body. There is no electronic link between camera body and telescope, nor are there any motors inside the telescope to move the focuser, lenses or mirrors (dependant on type of telescope).

Thus even when using Live View as an aid, it is the telescope focuser that must be moved by hand when trying to achieve focus.

An expensive and sophisticated Electronic Telescope Focuser could be used via the camera and laptop from such as a remote observatory and or a dedicated 'eyeless' imaging rig, but this is a simple Newtonian Telescope in its most basic form.

Thus hand focusing the telescope is the only option available, and even then may not work, largely due to back focus issues, hence the suggestion to increase the length of the focus train with a barlow lens to move the camera sensor outwards.

I use an empty Barlow tube with my ST80, when I use it as a camera lens for photography, but I have to manually focus via the telescope focus wheels. Can be quite a challenge.

Best,

Rich

[stargazer16]

A webcam would be very light and would allow you to create great images of the Moon, suitable webcams can be picked up for under £10. I bought one for £5 it works connected to my android tablet. I can create videos on that and then push then to the pc to proces

A webcam would be very light and would allow you to create great images of the Moon, suitable webcams can be picked up for under £10. I bought one for £5 it works connected to my android tablet. I can create videos on that and then push then to the pc to process.

Sounds like a interesting Alternative to taking pictures with my dslr!

[happy-kat]

There are many webcam threads a little diy on the webcam is needed, members have tried a cheap ASDA cam, the old XBox one is another very cheap and popular to have a go with.