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Dob height?


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Any recommended ways of raising the hight of a Dob mount for the taller person? It is really awkward and a pain in the neck using a straight finder scope directly overhead.

If Warthog reads this then thanks for the post about aligning the finder scope on Polaris. i have no view over 500 yds in my garden(45'at the most) or the front street.

ken

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You're welcome! :) I have a right-angle finder on my Newt, which save me a lot of neckstrain. I use a bog-standard RDF to get the scope in the general area. If it is very high overhead, I use a small, bright mirror to position the scope with the RDF. I understand Telrad has a diagonal mirror for their finder.

OH, some people with shorter dobs put the base on a box of some sort to raise them to a more comfortable height. You could do the same.

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Ken

I'm a tall dobsonian user with the same issues. Personally I prefer to stand when observing and the eyepiece height of my Skyliner 200P always causes stooping.

I'm currently thinking about making a solid 3 legged stand to sit the whole thing on and raise it up about 18 inches or so.

John

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Could a Plinth not be easily made to stand the Dob. on. Some sort of register could be included so it has no chance of sliding off. Bending for long periods is not recommended, and decidedly uncomfortable. :)

Ron.

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There is no reason wh you could not mount the finder base further forward - even mounting an extension beyound the front of the scope. You would need to add a counter balance weight at the back of the scope.

If it's a new scope you might void the warranty drilling new holes so check first.

A right angle finder certainly make life a lot easier.

Mike

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I'm intrigued that some users prefer to use a dob from a standing position - the idea of putting the eyepiece at 45 degrees from vertical came from William Herschel, who did it so that it would be most like sitting at a desk. I use a folding stool with mine and get on my knees when I need to use the straight-through finder for objects overhead, though I agree it's a pain and makes a right-angle finder better for those situations. Larger dobs obviously necessitate standing or using a step-ladder though I've always thought of that as a disadvantage rather than the opposite - a matter of personal taste.

Fixing the finder beyond the scope opening would be a solution but a plinth sounds a lot easier. Also be aware that if the finder eyepiece were beyond the opening then you'd be breathing a lot over the end of your scope and might cause dewing on the secondary. A more satisfactory solution might be a rigid dew shield extending over the opening and a finder attached to that (with necessary counterbalancing).

Personally I'd go for plinth and/or right angle finder.

Only right-angle I've ever used was an 80mm refractor that I mounted on the dob - but I soon learned this wasn't a great idea, because a refractor with mirror diagonal gives a left-right reversed image which makes map-reading very hard. It needs to have an Amici prism rather than mirror diagonal so that you don't get reversal - ordinary right-angle finders do have this.

Andrew

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You still got the skywatcher 250 dob Ken? Same 1200 length as my skywatcher 200? Do yourself a favour - sit down.

If you REALLY must stand up then build a stand like John says.

Although I've never used it for the scope yet I have a big motorcycle box stand in the shed that my old crosser used to sit on - might try it one day;

http://www.rpamx.co.uk/acatalog/Motocross_Box_Stands.html

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Darn tootin mate! I'd stand at a 16" lightbridge, wonder how Andrew gets on though :D

Maybe a rotating gallery with comfy chair and desk attachment - and a bus to fit it all in for dark-sky trips :)

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It's not the observing I am bothered about, i sit or stand whatever is easiest at that moment, it's that i have a north facing garden so i have been trying to findobjectsaroundCassiopeia....try using a straight through finder on a 10" Skywatcher dob whenCassiopeiais high up and you are 5'11"and have a dodgy neck. Anyhow i have a really big heavy plant pot, i would say it weighs about 30lbs that i have just tried placing it on. Works ok and is very solid. I am considering making it permanentby filling the pot with sand an cement and plonking it in the middle of the lawn. Or another solution, for anyone in a similar situation, would be to buy some kink of large plastic container to use as a mold for a sand and cement mix.

Thanks for the feedback everyone.

ken

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You could dig a hole to stand in, thus lowering your height rather than raising the scope! :D

Oh, you must be from Newfoundland! Welcome aboard! :)

On the question of the orientation of the image in the finder vs. the Dob: I bought a correct-image RA finder for my Newt. It is less confusing to use than the regular finder.

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I do a bit of both in my 16" dob.

When looking straight up I'll stand and anything between 30-80 degrees say I'll sit on a telescopic stool.

Anything below 30 degrees I'll kneel on the floor.

Got a Telrad and never had a problem with looking in it.

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