Look left

thanks for the advice. Then I would need a 2" tube lens fitting to go into the Crayford with an SCT screw thread so I could then fit a spacer to get the 105 mm focal length and screw camera to it taking into account the focal lens position? Would this still work? As the focus isn't great I as its about 5 mm too long, I thought it would still focus but as suggested the f ratio would maybe 0.6 anyreason whyfocus should be out.

Cheers, this is where I,m at present. I,be read it's 105 mm back focus which is what yours look likes. I,ve got the Crayford Motorised so I still get that ability to auto focus . It's 110mm so it's out a bit. I,m going to get a thinner 2" fitting with a 42mm thread so can fit Camera directly onto it so will get it around 6 mm closer . Hopefully that is enough. Will keep everyone informed. What's your thoughts on that!

Cheers Robert, from camera focal point to reducer lens is that 105mm .is that right.

Cheers mate.

What size of thread is on the Celestron 6SE SCT visual back ?

Has anyone got the Shoestring FCUSB to run on Autofocus in a free app. NINA,APT,Sharpcap etc. I,m not looking for repeatability re stepper motor. i know there are several comments on forums where it cannot be done because it's a 32 bit driver,not64bit as generally required. NINA has a relative Focuser ability but I cannot get it to work. I followed someone's advice and downloaded Bahtinof Grabber and in here you can run it in Poth mode for an Ascom driver and use 32 bit driver. Downloaded NINA as 32 bit and thought relative Focuser through Ascom would be the answer. So as the ap

Szymon i realise this is an old post however i,m now at the position to try out both the Hitec and or Shoestring FCUSB to gain Autofocus . How do I go about it? Can you assist please. i,m looking at Autofocus through any free app so NINA comes to mind. image shows the shoestring however I,ve also got the Hitec unit.

Does this mean that the 105 mm from the reducer to the camera focal point? Would this also take into account the travel of the Crayford, or go for 105mm ish and then use Crayford just to nail it.!

Thanks very much guys for coming back. Here's the setup and thanks to Callup and M40 for the distance. Stash _old ,s link shows the Reducer fitted to the FC on the SCT with a spacer between the reducer and the camera. However that means yourbrelying on the OTA focus knob to gain focus. On my Celestron 6SE you cannot get a great focus on it hence going with the Crayford. Now I know what I,m trying to achieve with the distances I,ll experiment.

Cheers Mike I,m trying to run before I walk, however by asking the questions now I can hopefully save a lot of frustrations later.

Sorry forgot to add that if I use an UHC filter with DMK41 or DMK 21 would this be of benefit on some targets? forgive me if these questions seem inappropriate or silly but we all have to learn somehow.

You've mentioned filters. If I,m Mono with a DMK41 I haven't done it yet due to weather but I have a Astronomix Planetary 642 filter. Yes it more for Planets naturally but it does cut out unwanted light and goes into some narrowband areas. Would I be cutting out on too much of the imaging info from the source to get any other benefit? i,m using a Celestron 6SE SCT with a 6.3 reducer to bring it to f6.3

Thanks a lot guys you've put some effort into this topic and wrote out quite a bit,I,m still absorbing it all.

I,m looking to put a 0.63 Celestron Focal Reducer on my Celestron 6 SE to reduce FL to speed up OTA for imaging in EAA. Do i put Reducer directly onto scope,then fit Crayford to this then ZWO 120 mc onto this. all assuming I have the right back focus to do this. If so I can use motor focus on the Crayford. or do I have to put Crayford onto scope,reducer ontomthis then Camera. Or forget Crayford and install reducer directly onto scope fir spare and the camera and use the course original focus knob ?

Can I ask what the 20H2 means?