Wide-T-Ring Fuji X with D52 to T-2i

55 to 60mm is a good approximate value for APS-C with a short flange-focal length like the X-Mount. In this case we recommend a 40mm and a 15mm T2 extension.

In any case, you need either S52 / M48 adapter #2958552 or the S52 barrel #2958551 to insert the camera plus T-ring into the 2" focuser of your telecope. The required back focus is 26mm - that is, the camera sensor will be 26mm behind the telescope's 2" clamp. To see if it works with your specific telescope, please perform the following test: Point the telescope at the moon, hold a piece of paper behind the focuser (without an eyepiece) so that the image of the moon is sharp on the paper. Now check, if there are 26 mm (better a bit more) of space between the fully retracted focuser and the paper. If yes, then you can use it on your specific telescope.

The Wide T-Ring features an S52 Dovetail which by default has an S52/T-2 (female) adapter inserted. So you can use all T-2 accessories out of the box as well as S52 accessories, which would offer the widest possible aperture. If you want to use the M48 standard, you would indeed need to purchase the S52 / M48 adapter #2958552 Please check also the application images with many explanations and examples as well as the product description.

Our Wide T Ring puts the Fuji XT3 26mm away from the sensor, while Celestron has designed the RASA for a distance of 25mm. So, the ring is 1mm too far away and does not work - officially. But as the image of Mr. Voltmer shows (https://www.celestron.de/ce_de/rasa-8-erfahrungsbericht-mit-fujifilm-x-t3-sebastian-voltmer/), it is still inside (or close enough to) the tolerances, so that the Wide T-Ring can actually be used and produce very nice images. But unfortunately, there is not enough space to use an additional filter drawer. We are working on a very flat filter holder and tilter for the RASA 8, the Baader FCCT (Filter Changer and Camera Tilter), but it will only work with astronomical cameras which need less backfocus than a DSLR/mirrorless camera. But please remember that there is not much use in using narrowband filters with a colour camera, as then only one fourth of the pixels is used (usually those sensitive for red, while those for green and blue get no signal). For monochrome astronomical cameras, the FCCT will be an interesting solution. We hope that it will be available in spring 2020.