Thread: any backyard astronomers here?

Originally Posted by Noisykids

what i'm looking at is only 700 bucks and has a 10" primary. that seems huge for that kind of cmuf. it's not motorized but has encoders in the mount which you don't have to use so you can do it like they did in the old days by star hopping. i've found the andromeda galaxy by doing that. then again, there is a 10" dobsonian with no bells and whistles almost brand new on craigslist a couple of towns away for really short money.

the biggest problem with my current scope is the finder is a half a binocular screwed to the tube. plus the whole thing is jiggly even after being rebuilt. at one point during it's life the duct tape wedging the spider in place dried out, and the whole thing fell onto the primary, damaging a minimal area. i don't know where the tool is anymore so even if i had the psychic energy i don't know if i could repolish it, or god forbid, have to go back to fine grinding and repolishing.

i guess i've done enough observing to know that i'm not going to get national geographic quality views. I made a 4" dobsonian out of a purchased mirror before i committed to making a mirror and was walking home with it one night after looking at a spectacular view of saturn. i got accosted by a drunk down the street who wanted to know what i had. i set the scope up, let him take a peek, and he came away from the eyepiece saying, "Wow, that's really real."

Star hopping is the tried and true method. Even with the encoders it's not fool proof so sometimes you have to nudge the tube a bit in the right direction to center the desired object. I had to learn where stars and other objects were back before there were encoders so I have kind of a biased opinion on those. I think it's best to just know where all the major naked eye objects are in relation to each other. Then if you're out somewhere and see someone new at the hobby with a little scope or a pair of binoculars having a hard time you can say, "No, it's over there."

An 8" is a huge improvement over a 4". It has over twice the light gathering capacity. Things start getting exciting with an 8" mirror. A 10" is even better. As you've noticed the other accessories make a difference. I know how frustrating a bad finder scope can be. They don't have to be an actual telescope themselves. They just need to be steady and aligned correctly. A cheap 10" dob that is sturdily made is a great find. Bells and whistles don't help that much but good quality does. Remember that magnification not only increases the view but it also increases the wobbles. Check any scope you can see in person to make sure the wobbles are kept to a minimum.

Lori

Just checked the scope. It is Sky-Watcher Skyliner 200 with a Dobson mount. Probably not the best there is but ok for the kids 1st scope. We've been considering getting an adapter for Canon SLR mount. Any recommendations where to get such with reasonable price?

I've only ordered from Orion but that's in California. I don't know what's available in Europe. Orion might be willing to ship there though.

Lori

I've had both a large 12" Dobsonian and an 8" Schmidt-Cass. The Dob had Intelliscope, and the S-C has Goto. I preferred the Intelliscope, primarily because it was faster just to push the scope around rather than wait for the Goto motor to find its target. And the Goto only goes in one direction, to the right, so if your next target is 5 degrees to the left, it'll make a full 355 degree turn to get there! S-Cs also have a problem with fogging up much earlier in the evening than a Dob will.

The problem with the Dob was that it was huge. I used to have a Jeep Cherokee, and I could barely get the whole getup inside. A 10' is a bit more manageable but still large. It's hard to get a sense of how huge they can be from just pictures in the catalog. The Dob, being a Newtonian, also had a lot of maintenance issues. The mirrors had to be collimated a lot, and the larger the aperture the more sensitive the mirrors were to getting knocked out of place. I assume because they were heavier.

My current 8' Schmidt Cass works well, though. It doesn't have the maintenance issues and is very portable. If I had a stationary viewing area, though, I'd prefer a Dobsonian.