Telescope Reviews: Ah criminy. Not again

I'm a "portable setup" Atlas/Canon user and can offer the following thoughts for you:

1. You'll be using a computer for imaging so there's no reason not to use it to control the mount. This eliminates all differences between hand controllers.

2. Your deck, if supported on posts, isn't the ideal base for an imaging scope but will definitely work better if you run the scope and camera(s) from inside the house. Vibration dampening pads under the tripod legs can also help here. A deck that's on top of part of the house (ie the garage) will probably have vibrations from people moving around inside the house.

3. EQMOD, a fabulous tool for running an Atlas mount, has an unbelievably accurate pointing mechanism that works best with a permanently mounted scope. If you're setting up every evening, then you'll need to build a new pointing model every night. I usually build mine as I image, with only two or three initial alignment stars. EQMOD's polar alignment routine, combined with the Atlas polarscope, should give you a good enough polar alignment that your guide scope and camera will easily give you 3+ minute exposures with the Canon camera. I'd expect that your light pollution will limit you to shorter exposures than that.

4. If you're not using your deck for other things, you could consider a simple waterproof cover for the mount and tripod and occasionally leave it out during the daytime. If you do this, you'll need a way to attach the tripod to the deck to prevent its being blown over in a high wind. I have a dark site in SW New Mexico and cover my scope this way when I'm there for a week or so.

The Ioptron mount is quite a bit lighter than the Atlas. Its high weight limit is most likely a visual use limit. The Atlas, also known as an EQ6, has a number of weight limits depending on who is selling it. Orion's 40lb is at the lower end of the weights. The general weight rule for imaging with these mounts is to image at not more than 50% of the mount's maximum limit. In all cases, good balancing of the mount is critical to obtaining good images.

The Ioptron is still a relatively new mount, only a few years old. The Atlas has been around for a much longer time and there's been a lot more time to get its kinks worked out.

I suspect that whichever mount you get, you'll have a learning curve to climb before you become somewhat happy with it. Like many things, you'll always suspect that the grass was greener on the other side of the hill and you should have gone there first.

Phil