Spacer Question

[Sarum]

I'm in the process of upgrading my current  setup to one more up-to-date and more portable.  The new setup is a Sky-Watcher Evolux 82ED OTA on a Sky-Watcher AZ EQ5-GT Go-To GEQ & Alt-Az mount.  I intend this to be an imaging setup, and to that end the scope is fitted with a Sky-Watcher .9x Reducer/Flattener .  The imaging camera is an ASI1600MC with a back spacing of 6mm between the camera case and the chip.  My difficulty is deciding what spacer combination is needed to achieve the required 55mm backspace between camera and reducer.  I wonder if any kind soul has any advice on what spacer combination I will need ?

Thanks in advance for any help,

Roy

[Elp]

When imaging it's always useful to have a set of these at hand as well as less than 1mm rings to fine tune, they also do the below as a set in 5mm increments:

https://www.firstlightoptics.com/adapters/astro-essentials-t2-m42-extension-tube-set-4mm-5mm-6mm-7mm-8mm-9mm.html

From the bottom of the thread of the reducer (the physical stop) you need to make up the 55mm minus the 6.5mm from your front of camera to sensor distance with the extension rings, then attach your camera. The 1600 should have come with an 11mm female to female m42 ring to fit onto the nose of the camera making the distance remaining to make up 55-17.5 = 37.5mm. if youre using filters you need to add approx 1/3 of your filter thickness to the 55mm, most use around plus 1mm.

[Budgie1]

Could you confirm the camera you have? There is no colour version of the ASI1600, just the mono version which is the ASI1600MM and has a 6.5mm distance between the sensor face & the front of the camera body. 

If you have the ASI1600MM Pro, are you using any filters or a filter wheel with the camera? 

There is the ASI2600MC Pro camera, but this is 17.5mm from the sensor face & the front of the camera body. The links on both these cameras have diagrams for setting the correct distance to your scope and a list of the required adaptors, so I hope that helps.  

Edited February 21 by Budgie1

[Sarum]

Thanks Martin,

I should have been more precise,; there is a colour version of the ASI 1600, though it is no longer in production.   The ZWO site does indeed quote 17.5 mm, but that also includes an 11mm threaded collar .  My question was really about the number and thread sizes needed to link up with the flattener   

Sorry if my question wasn't very clear, but thanks for the response.

Roy

[Sarum]

Thanks Martin,

I should have been more precise,; there is a colour version of the ASI 1600, though it is no longer in production.   The ZWO site does indeed quote 17.5 mm, but that also includes an 11mm threaded collar .  My question was really about the number and thread sizes needed to link up with the flattener   

Sorry if my question wasn't very clear, but thanks for the response.

Roy

[Sarum]

Sorry Elp,

For some reason I completely missed your post., but many thanks that's exactly what I was looking for. 

Cheers,

Roy

[Budgie1]

2 hours ago, Sarum said:

Thanks Martin,

I should have been more precise,; there is a colour version of the ASI 1600, though it is no longer in production.   The ZWO site does indeed quote 17.5 mm, but that also includes an 11mm threaded collar .  My question was really about the number and thread sizes needed to link up with the flattener   

Sorry if my question wasn't very clear, but thanks for the response.

Roy

Sorry Roy, I wasn't aware of the ASI1600MC camera and I note it doesn't have the set point cooling.

In that case, the distance is 6.5mm from sensor to camera body, plus the 11mm spacer, making your 17.5mm. ZWO also supply M42 x 21mm & M42-M48 x16.5mm extenders, when added to the 17.5mm on the camera it takes the distance to the required 55mm. 

As Elp has said, it's always handy to have some 1mm thick spacers for fine tuning if necessary.