Home :: ASTRONOMICAL TELESCOPES :: Apochromatic Refractors :: Primaluce Lab APO Refractors :: Primaluce Lab Deluxe 0.8x Reducer-Field Flattener for Refractor Telescopes with T-thread

Primaluce Lab Deluxe 0.8x Reducer-Field Flattener for Refractor Telescopes with T-thread

Manufacturers View products from this brand

low Low stock (1)
0.80 kg
Our price:

By reducing the focal length of a telescope (for example, 500mm focal length becomes 400mm), this 0.8x reducer/flattener increases the area framed by the camera sensor.

In addition, decreasing the focal ratio of the telescope (for example AIRY APO80 f/6.25 becomes f/5), allows you to record weaker details. Designed for photographic use with AIRY telescopes, it offers extended correct field and it can be used with various refractor telescopes.

Focal reducers are used in long-exposure astrophotography of deep-sky objects like nebulae, star clusters and galaxies, and in order to get the best images, it is important that the field of view framed by you camera to be flat (that is, the stars have point shape in all the field). Since reducing the focal length also the field is generally reduced, in this table you will find not only the focal length and focal ratio created by the use of the 0,8x reducer/flattener but also the size of the corrected field. This way you can check whether your camera sensor will be suitable for use in astrophotography (eg Atik 460EX CCD camera has 15mm diagonal sensor so it needs at least 15mm of flat field to have images with pinpoint stars in all over the field):

focal length
focal ratio
Focal length with
0,8x reducer/flattener
Focal ratio with
0,8x reducer/flattener

Flat field
diameter (mm) 

AIRY ED72 432mm  f/6  345mm  f/4.8  15mm
AIRY APO80  500mm  f/6.25  400mm f/5   15mm
AIRY ED90 500mm  f/5.5  not available  not available  
AIRY BLACK 90T  600mm f/6.7  480mm  f/5.3  19mm
AIRY ED100  600mm f/6   480mm  f/4.8  17mm
AIRY APO104T   650mm f/6.25   520mm f/5  16mm
AIRY APO120   900mm f/7.5   720mm f/6   16mm
AIRY APO130T  860mm  f/6.6  688mm f/5.3   15mm









The 0,8x reducer/flattener into 50.8mm connection of the focuser (in front it has a thread for connecting 50,8mm diameter filters). Rear (camera side) it has a T2 male thread and therefore it can be screwed directly onto the DSLR cameras ( using a T2 ring of the camera brand) or to a CCD camera (with T2 female thread).

700Da camera connected to the AIRY ED100 refractor with reducer/flattener

This reducer/ flattener, in order to offer the best performance, requires that the camera sensor is positioned at 55mm distance from the reducer thread. This is precisely the distance provided by connecting the DSLR camera with T2 ring. For the use of CCD camera (that offer a sensor placed in more front position than the one of a DSLR camera) it is necessary to add a T2 extension. To calculate the required thickness, you can use the formula: required T2 extension = 55mm required distance - CCD camera back focus.

So, for example, if you use a QHY8L CCD camera that has 20 mm backfocus, the T2 you need will be: 55 - 20 = 35mm.

: *
: *
: *
Type the characters you see in the picture:

Vixen Porta II Altazimuth Telescope Mount
Primaluce Lab XP 90° 50.8mm 2" 99% Dielectric Mirror Diagonal
Primaluce Lab Deluxe 2.5" Field Flattener for 90T APO
Primaluce Lab 140mm PLUS Vixen Plate - Dovetail Bar
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 cookie settings on this website are adjusted to allow all cookies so that you have the very best experience. If you continue without changing your cookie settings, we'll assume that you are happy to receive all cookies on our website. However, if you would like to, you can change your settings at any time using the Change cookie settings link in the Special menu.