Choosing between IMX455 and IMX571 cameras.

[tooth_dr]

I see there is a thin 10mm OAG from QHY, but this needs to be used with the 3mm spacer 020079 as it appears to be a connecting adapter adding an M42 thread or M54.  So this still leaves me at 21mm 

 

Edited November 16, 2020 by tooth_dr

[DaveS]

The 17.5mm is the distance from the sensor to the end of the circular dovetail.

BUT

There is no thread on the dovetail so you have to use the supplied adaptor which gives you the 23.5mm figure. From what I've been able to work out from the Astrograph site, and after emailing Rupert, the adaptor is screwed on to the rear face of the FW using the six small screws.

The adaptor itself also has a 54mm thread for attaching to other filter wheels etc.

[tooth_dr]

2 minutes ago, DaveS said:

The 17.5mm is the distance from the sensor to the end of the circular dovetail.

BUT

There is no thread on the dovetail so you have to use the supplied adaptor which gives you the 23.5mm figure. From what I've been able to work out from the Astrograph site, and after emailing Rupert, the adaptor is screwed on to the rear face of the FW using the six small screws.

The adaptor itself also has a 54mm thread for attaching to other filter wheels etc.

Thank you Dave. I’ve emailed Bern too with a few questions too. I was planning on using my existing Atik EFW3, it’s 7 x 2”, but if QHYs screw fitment is bespoke to QHY, this means I need a new EFW and a new OAG. However the OAG says it’s only compatible with the M filter wheels not the L, and the M one doesn’t come in 7 x 2”.   👎🏻

[DaveS]

Have a look at This page on the Astrograph site. The FW and OAG have some further drawings and dimensions.

[Laurin Dave]

Whatever dual scope you choose make sure the adjustment saddle (JTD or whatever) can handle the load or you’ll be in differential flex territory ..  although short CMOs exposures will help mitigate this 

[tooth_dr]

48 minutes ago, Laurin Dave said:

Whatever dual scope you choose make sure the adjustment saddle (JTD or whatever) can handle the load or you’ll be in differential flex territory ..  

That’s a good point though as the 120 is probably heavy, I hadn’t considered that 👍🏼

[tooth_dr]

I ended up putting in my order for the 2600MC this afternoon.  I plan to use this on the Epsilon.  I also ordered the M48 filter drawer, and the NBX filter.  This decision was highly influenced by the recent amazing images from this camera and the camera/filter combo.   I'll have a nice image scale of 1.55"/px too.