Skywatcher Explorer 250px vs 250pds

[jon-owen]

I've been trawling various pages and cannot find the difference between these two OTAs.

They both appear to be F/4.8 - is the difference optical coating / secondary mirror size?

Thanks!

[russ]

Coatings are the same i think. The only differences i can remember are a dual speed focuser (hence DS), the larger secondary and some extra inward focus travel due to the reposition of the secondary.

[fatwoul]

Coatings are the same i think. The only differences i can remember are a dual speed focuser (hence DS), the larger secondary and some extra inward focus travel due to the reposition of the secondary.

Does that also suggest that the one with more inward travel might be better suited to astrophotography? Astrographs generally seem to have more travel close to the OTA.

[Digz]

I have read that the DS is better suited for AP but I have still found insufficient inward travel without a Barlow attached. Despite that I have yet to try with the disassembled 1.25" adapter which should solve this problem. Also I think your supposed to be able to adjust the secondary mirror to resolve this issue as well.