Is the 174 mini too big?

c131frdave

Will the 174 mini work with the standard size OAG? I have the regular OAG and the prism looks to be too small for the 174 mini's chip. I don't want to buy one and then have to send it back. Thanks.

w7ay

c131frdave I don't want to buy one and then have to send it back.

Find a better OAG.

If you look through this forum, you will find at least one thread where a user had to file the opening in the stem to make it a better match to the IMX174 sensor size.

Chen

WalterT

w7ay a user had to file the opening in the stem to make it a better match

Guilty as charged. The OAG opening is not even big enough to work with the advertised cameras. I filed and enlarged the opening by about 2X and that was barely enough to accommodate the sensor off my 290MM Mini without vignetting.

If you must use the 174 just get a Celestron OAG if you have the backfocus to accommodate it.

w8xn

As one who went from a ZWO OAG and 290MM mini to a Celestron QAG and 174MM mini, I can say that the differences are huge. I even tried the 174MM mini with the ZWO with little success, the 8x8mm prism is just too small in the ZWO. The 12.5x12.5mm prism on the Celestron OAG perfectly fills the 174MM sensor. Guiding at 2000mm FL is superb with the Celestron/174MM mini combo.