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What to do?


Kaptain Klevtsov
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The night of 3rd to 4th of April saw me playing out under the 20% or less clouds. I had fun and got some things sorted with the equipment. I discovered that the HEQ5 goto thingy DID work, it points at things that I can't see because its not dark where I set up the kit. Hanging the DSLR on there and just trusting it gets me a picture of the faint fuzzy that I swore wasn't there.

My method of imaging with the DSLR is to point the 'scope at Saturn or the moon to get a good bright thing in the frame, then snap away adjusting the focus until it looks good in the preview display. For this the Orion electric focus doodah is great as I can put it in slow and dab the button each way until the focus is asd good as its going to get. My current problem is with the degree of zoom on the preview, as I have got 20 each of M51 and M101 with no clouds in the way, usual light pollution and I should be ready to go.

When the pics get into the system and I can see them full size, the stars are all circles, and the Messiers are messier than they should be. Waste of time (but fun) doing the fiddly bit then.

So today's how much do I need to spend question is:-

1) Modified webcam for long exposures so that I can see the full image on screen to get the focus right.

2) Stiletto focusser to get the DSLR focussed right.

3) Long cable to dump the DSLR onto the laptop to check focus before doing lots of pics.

4) Something even cheaper ( I think the options above are in reverse cost order).

To add a bit here, I think that the really good focussing that I did on Saturn went away a bit as the 'scope moved. Could be the tube flexed or the camera settled into a different position. The way I did it has worked before (or so I thought) so this might be something that I have learnt tonight.

With the webcam option, I would prefer a single cable option, if one is available, as falling over the wires is bad enough already.

Your opinions and thoughts are welcome and I look forward to them arriving as I sleep. If you are still up, good luck, if you're not, bad luck, shame about the clouds.

Captain Chaos

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lots of people use external screens plugged into the dslr to see the results on a larger screen rather than a laptop. something like a portable dvd player or psp with video in should work. i use the moon to focus as its BIG. you could try a hartmann focuser as its free. cereal packet type thingy with holes cut in it.

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Thanks Gordon for the screen idea, I'll look into that. What happens when I focus is I pick something bright (Saturn) and snap away at that until the fully zoomed image on the preview is in focus. It was last night, in focus, on Saturn. Then I told it to goto M51, which is the other direction if you will, and snapped away at 30S exposures. These DSO images are too faint to see on the preview screen - hence the planet. When I later put them on the computer the M51 and M101 images were enough out of focus to be annoying.

I'll have another play tonight if the clouds stay away, I think I'm going to have to dump to the laptop to check focus so I'll investigate today what logistically I need to do.

Captain Chaos

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OK so now I need to spend some more dosh, what else is new?

Well this:-

image.jpg

The first processed result of my out of focus image. Definitely a could do better one, thats a job for tonight.

BTW anybody know where I can lay my hands on some sort of DSO camera for not too much dosh?

Captain Chaos

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HI CC, if that image had been taken in focus - it would have been blumming superb!

Hope you not after a new camera because of this image? It's a fine image with the only issues being focus!

Managed to remove some of the glow and the slight start trails... Hope you don't mind!

Ant

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Nothing wrong with that apart from focus as Ant says. You've got the exposure right, and the detail is there wanting to appear. I would have been well chuffed if i'de taken that! Explore the hartman mask idea as then you can use a nearby bright star to focus and you shouldn't have too much trouble. You can also look into DSLRfocus software but then you need your laptop and cables and it starts to get messy.

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M101 didn't do as well as M51:-

image.jpg

And yes it was because of the frustration that I contemplated throwing more money at it. Spitdummyitis is the technical term I think.

Tonight I'm going to try linking the D50 to the laptop for download while its still on the scope. That way I think I can get better focus. I'm also going to position the scope so that the street lights don't pour down it's throat as they did last night. More filters might be on the shopping list as well.

Captain Chaos

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Hi CC,

Images look pretty good to me, a light pollution filter will help loads (I swear by the CLS), as for focussing I always try and focus on a star rather than a planet or the moon allways seems sharper to me, I went through the same process as you, found using the viewfinder of the 350D quite difficult and time consuming so made a hartman mask, made things alot better, toyed with the idea of a screen for checking focus, but decided to get a Stiletto focuser can honestly say it's a wonderful bit of kit, simple to use and focus is allways spot on, only point I will mention is that when using it, it helps if your scope focus can be locked as removing the stiletto without focus locked it would be possible for you to shift focus withut knowing you'd done this, other than that it's a fine piece of kit, well made and at a good price.

Hope this helps

Alan

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  • 3 weeks later...

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