Why don't telescopes have electric focusers
Category: Astronomy Equipment
Posted by: Tom How
A thought struck me today. Why don't telescopes have electric focusers?
If you are doing serious astrophotography with your telescope then a motorised focuser is a must have. An ASCOM compatible motorised focuser combined with some software like FocusMax makes focusing a telescope a joy. FocusMax learns the parameters of your telescope and automatically brings your CCD camera to prime focus automatically under computer control.
This means a lot of astrophotographers end up fitting an electric focuser to their telescope.
It is a mystery to me why expensive telescopes never seem to come fitted with built in electric focusers. Take for example the AG range of corrected newtonian telescopes from Orion Optics. These telescopes cost in the region of £5000, yet only have a manual crayford focuser. It would add about £100 pounds to the cost to fit an integrated geared stepper motor system along with a usb interface. Most astrophotographers have a USB hub on the telescope, so you could just plug the scope in! These scopes already have some wiring for their fans.
Why don't they do it? The usual excuse is probably that most people will want to fit their own choice of electric focuser. Actually, Orion think you should spend another £2000 on the Finger Lakes in-line focuser. I suspect most people would be much happier to have a packaged, integrated USB controlled electric motorised Crayford focuser built in rather than having to add one. This especially applies to the £1000-£2000 price range of scope.
The USB connection could be used for other things such as a built in video camera on the finder scope. Heck, for not very much money you could add 3 stepper motors to the collimation screws and use some software feedback from the CCD camera to collimate the scope automatically. Come on telescope makers, let's have some imagination!
If you are doing serious astrophotography with your telescope then a motorised focuser is a must have. An ASCOM compatible motorised focuser combined with some software like FocusMax makes focusing a telescope a joy. FocusMax learns the parameters of your telescope and automatically brings your CCD camera to prime focus automatically under computer control.
This means a lot of astrophotographers end up fitting an electric focuser to their telescope.
It is a mystery to me why expensive telescopes never seem to come fitted with built in electric focusers. Take for example the AG range of corrected newtonian telescopes from Orion Optics. These telescopes cost in the region of £5000, yet only have a manual crayford focuser. It would add about £100 pounds to the cost to fit an integrated geared stepper motor system along with a usb interface. Most astrophotographers have a USB hub on the telescope, so you could just plug the scope in! These scopes already have some wiring for their fans.
Why don't they do it? The usual excuse is probably that most people will want to fit their own choice of electric focuser. Actually, Orion think you should spend another £2000 on the Finger Lakes in-line focuser. I suspect most people would be much happier to have a packaged, integrated USB controlled electric motorised Crayford focuser built in rather than having to add one. This especially applies to the £1000-£2000 price range of scope.
The USB connection could be used for other things such as a built in video camera on the finder scope. Heck, for not very much money you could add 3 stepper motors to the collimation screws and use some software feedback from the CCD camera to collimate the scope automatically. Come on telescope makers, let's have some imagination!
