First refractor for imaging

[alexbb]

4 minutes ago, Paolo Silvestri said:

So, should I go for the WO Z61 (360mm) even though there is a quad for about only 50€ more? Anyway thanks for the suggestions.

I saw a few good results at focal lengths longer than 300mm, but there were just a few. Personally, I'd rather choose a shorter lens

[Paolo Silvestri]

40 minutes ago, moise212 said:

I saw a few good results at focal lengths longer than 300mm, but there were just a few. Personally, I'd rather choose a shorter lens

The star adventurer seems to perform good at focal <400mm as shown by some samples on astrobin, as it can easily keep tracking for about 2 mins. The Ioptron shown on Astrobackyard goes the same, my only doubt is about which refractor to buy, tbh I don't know much about other options but the Z61, which is a bit expensive cause it does not come out with the flattener (and it costs a lot too).

[alexbb]

There's an even smaller TS ED doublet, the 60/360. Coupled with the 0.79x reducer/flattener, you get a final ~285mm focal length.

[Paolo Silvestri]

2 hours ago, moise212 said:

There's an even smaller TS ED doublet, the 60/360. Coupled with the 0.79x reducer/flattener, you get a final ~285mm focal length.

Gosh, just the field flattener is 235€...including the recommended extension tube it's 700€. With 10€ less there is the Tecnosky quad 65/420.