pfrancke Loc: cold Maine

hi guys, sorry for my question if it has been discussed elsewhere. I've used a rokinon 24mm and have a canon 400mm prime coupled with a canon 6d. My question is about hooking such up to an EQ mount like the Orion skywatcher.

dumb question 1: With 24mm would I see a lot more with camera mounted at longer than 15 sec exposures and avoid star trails?

dumb question 2: With 400 mm and perhaps a 1.4 extender hooked to a small eq mount, could I find and get long exposure of a nebula?

In short, is there any value in hooking a camera up to such a mount directly or is such simply futile and frustrating?

skylane5sp Loc: Puyallup, WA

What mount are you talking about? Is it driven?

pfrancke Loc: cold Maine

hi skylane, I guess that's part of my questions too. I take it that if it wasn't driven, it would just be a sturdy tripod that you could aim with. I was thinking about orion skywatcher pro at 850 or since my wife would kill me anyways, perhaps orion Sirius.

skylane5sp Loc: Puyallup, WA

Take a look at the iOptron Sky Tracker...

pfrancke Loc: cold Maine

thanks, with the price,I really have to consider that. Place on a solid already owned tripod and it becomes a perfect camera accessory. Portable and would get taken to upcoming trip to southern Utah where a larger mount would be left behind.

Straight Shooter Loc: Newfoundland, Canada

Yes, the Ioptron is great for portability. However, a 6D + 400mm lens would be overloading it. It's great for Milky Way shots with a wide-angle lens (around 15-25 mm), and you may get good results with a moderate zoom (maybe up to 150 mm). If you want to use a longer lens, you would probably need to piggy-back it on to a guided telescope - or connect the camera directly to the scope.

pfrancke Loc: cold Maine

thank you Mike, that is good to know. I'm still considering the Ioptron for it's portability and as a learning tool that would let me know if I like doing this enough to warrant a larger purchase - but for now I'm probably safest just seeing if I can find something interesting to point the camera to with the telephoto lens and what it gives me. Depending on what the telephoto lens is capable off... that would help me determine if it is worth investing in something that could handle it, or if I would be better off sticking to shorter lenses..

I just found an app for my Android tablet called SkySafari4 which lets me know what is up there and when it is there. If the sky is clear I'll try to take a few 10 sec exposures with the 400 mm just to see what it is capable of seeing - recognizing that it would sense more if given more time.

On a slightly different topic, I'd been reading that light pollution filters can be a very effective tool. Is there such a filter for cameras or are these available only for telescopes?

pfrancke Loc: cold Maine

Using sky Safari, I thought I was able to identify Spica. So I took a shot at it and got four 5 second captures. Then I quickly, poorly, and manually stacked/blended the four images and messed with levels.

Even at 5 seconds, with the 400mm I see quite a bit of star trailing (though some of that might be stacking error). I see more stars than are on the sky Safari screen so I must be doing better than magnitude 9.6.

Now I have to mess with other lenses and see if I can find a nebula out there. I'm torn between cheap and better, and I'm torn not knowing how hard it would be to set up and calibrate a tracker.

I am left wondering what a tracked 5 minute exposure would look like regarding how "deep" the camera can see.

(Download)