http://www.astrobin.com/152306/0/ maths reports the full size image as 0.454 arc seconds per pixel (T3i DSLR at prime)
Since I wrote my previous review I've had this Frigate of a telescope out on the DX six times. Each time something about its weight, balance or focal length has been able to frustrate me until I gave up and got a full length D rail and rings. TBH the best use I've found for the short included dew shield is to strap a much longer wrap of black poster board around it. With that enormous corrector up front you end up with a razor thin balance between dew-zapping and expanding the tube out of good focus. In the cold with gusty wind you can watch it do this so adding more shield length I'd consider mandatory. If not adding insulation around the whole telescope... f12 is just a tad deep for portable astrophotography. The light path's exit diameter is bleedingly close to the full 2" of the rear tube, OAG is a definite go and pretty much mandatory unless you get one of Orion's Mak for a guiding telescope. The ONLY negative I have about this telescope is that the mounting arrangement is a flimsy little piece of extruded aluminum with Allen bolts that go through the accidentally threaded scope body into a pair of cheap lock-nuts. In order to mount it on the rings I had to accept a rolling nut on the inside. Easy to correct if you're careful but just poor design on iOptron's part. It could well be worth it to use risers under your mount rings instead of removing the supplied ***** short rail then having to remove the nuts at a later day (they WILL come off inside if you try to put the bolts back through them). A clean 4.7 stars imho. Having only one (correctable!) bug in the whole works makes an excellent product!
This OTA offers very high optical and mechanical quality for a modest price. Collimation was spot on out of the box. Optics provide high contrast and bright views. With the supplied 2 inch visual back and a 38mm 70 degree eyepiece, you can get a near 1.5 degree FOV. The OTA is robustly built and the dew shield is a nice touch. The focuser is very smooth with very little image shift. The only negatives would be a moderate cool down time and weight. I guess the tank like construction has its price. All in all, it really good where it counts... optically and mechanically. The listed specs are off though... it's a 150mm f/12. Thanks for the head's up! iOptron initially introduced this scope as a 152mm f/12.5. I have changed everything to match the current product specs. - Penny