Home :: PHOTOGRAPHY :: Astrophotography :: ZWO ASI CMOS Cameras :: ZWO M42-M42 (T2-T2) 21mm Extender Ring

ZWO M42-M42 (T2-T2) 21mm Extender Ring

Manufacturers View products from this brand

in In stock (5)
Model
Z461-T2-EXT-21
Weight
0.15 kg
Our price:
£15.50
including VAT 20.00 % ( £2.58 )
Qty

B2-2

ZWO M42-M42 (T2-T2) 21mm Extender Ring

This adapter might help you to achieve 55mm back focus with your camera.

Example 1:

ASI071MC-C has got a sensor to flange distance of 17.5mm, then you add this 21mm T2-T2 extension and then you add a 16.5mm M42-M48 adapter or a ZWO OAG (off axis guider) that has got the same thickness of 16.5mm. So basically if you use an OAG then you don't need this adapter, but if you don't use a ZWO OAG then this adapter/extension is necessary to achieve 55mm back focus. Basically, this adapter replaces the OAG and provides a M48 connection to the telescope.

 

Example 2:

The ASI1600MM-COOLED camera has got 6.5mm focal flange distance, add a 11mm T2 extension, add this 21mm T2-T2 extension and finally add a 16.5mm M42-M48 extension to achieve 55mm back focus to the sensor with M48 connection to the telescope.

Here is a bit of history...  Many optical elements like coma correctors, reducers, field flatteners etc. have been designed for Canon cameras that require 55mm back focus to the sensor, so this is how we ended up with this figure: 55mm, however we should note that a 55mm back focus is not always a requirement and some optical elements might require a different distance or in some telescope systems you might not even need to worry about back focus (i.e. when you don't use additional optical elements...)

SPECIFICATIONS

  • Colour: black
  • Optical length: 21mm
  • Overall length: 25mm
  • Telescope side attachment: female T-thread (M42x0.75)
  • Camera side attachment: male T-thread (M42x0.75)


Images are for demonstration purposes only.

: *
: *
: *
 
Lacerta Variable Locking T-2 Extension 24mm - 34mm Optical Length
£30.40
365Astronomy T2 40mm Extension Tube - 40mm T2 Extender - BLACK
£14.70
365Astronomy T2 20mm Extension Tube - 20mm T2 Extender - BLACK
£13.80
365Astronomy T2 10mm Extension Tube - 10mm T2 Extender - BLACK
£12.60
ZWO M42-M48 Adapter 16.5mm Extender Ring
£15.50
There have been no reviews

Only those who bought this product are allowed to add review
If you've already bought this product, please sign in and add your own review!
 
The website uses cookies to allow us to better understand how the site is used. By continuing to use this site, you consent to this policy. Click to learn more.