About the 200P

[Matthew]

When i had a 200p Ant i used to use elasticated shower caps to cover the ends of the scope,Steve and Peter have 200p Dobs why dont you have a look at them during the the next observing session ( i know they wouldnt mind )

[John]

Would the view at 5min cooling time still be better than the view through my current telescope at 30min cooling time?

Small refractors cool really quickly - your 70mm is probably usable almost straight from the house. One of the things that comes with larger aperture scopes, of all types, is the need to allow them to cool to something closer to the outside temperature.

An 8" newtonian is usable at low power after just a few minutes but if you want to examine the planets / moon / binary stars at higher powers then the tube needs to have cooled to allow the warm air currents within it to dissipate either though the walls of the tube or out of the open end. A scope full of air currents will not show good high power images of anything.

[Ganymede12]

My only concern is that I normally only get around 1 and a half hours in my garden observing and I don't feel that my telescope would be safe in the garden for 50 min without me there.

It's not too big a worry though as I know that I will be getting a 200P indefinitely.

[stevetynant]

When i had a 200p Ant i used to use elasticated shower caps to cover the ends of the scope,Steve and Peter have 200p Dobs why dont you have a look at them during the the next observing session ( i know they wouldnt mind )

At the moment theres me, Pete, Lenny and Clayton that I know of in our group with 200p's as well as the Celtic Deacon who hopefuly can join us this year - theres bound to be one or all at the meets over the next few weeks so like Matt said Ant your welcome to try before you buy. I keep mine in a spare bedroom wardrobe with no issues at all. Take it outside by the time you get your gear together, collimate it - theres just enough time for a quick scan of your books and charts and away to go - or if your at the observing meets in Blaenavon- set it up and then start gossiping with the rest of us for an hour - plenty of time to cool down - definitely not one to worry about.

[Ganymede12]

Is there anyway to check the collimation during the daytime or do you need to focus on a star?

[jimmyjamjoejoe]

Is there anyway to check the collimation during the daytime or do you need to focus on a star?

You can do it in the day with a cheshire or laser, but when you move the scope outside later that night you'l need to check it again.

[RikM]

Using a Cheshire, it is easier to check in the day time, or at least evening before it gets really dark. You can shine a torch on the reflective plate and do it that way (actually I often do this with a red LED headlamp) but it is not as easy.

[Ganymede12]

Thanks, I was planning on getting a Cheshire collimator anyway

One more thing. In my garden I am surrounded by walls and houses so looking at things 25 degrees altitude is impossible with my current scope - and that's on a tri-Pod! The dobsonian will be closer to the ground and because of the parallax effect I will be able to see less of the sky! How much of a problem will this be?

[Naemeth]

Thanks, I was planning on getting a Cheshire collimator anyway

One more thing. In my garden I am surrounded by walls and houses so looking at things 25 degrees altitude is impossible with my current scope - and that's on a tri-Pod! The dobsonian will be closer to the ground and because of the parallax effect I will be able to see less of the sky! How much of a problem will this be?

As long as you observe things above that, you will not notice any difference .

[dtr42]

use stellarium it will tell you whats avaiable at what height and when [use the forward button to work out what is viewable [altthough i think mars and saturn may not clear your roof at the moment as thye dont clear mine at all from back garden [have taken to going to a field opposite my house with clear views above 10 degrees ]

[jimmyjamjoejoe]

I see what you're saying, but i dont notice ~much~ difference between my tripod mounted frac or the dob. It is a little lower, but i generally dont look at things when they're that low anyway. Sometimes i find i just have to move a few paces back etc to catch something over the fence.

[Ganymede12]

What is the cheapest mount (which has a tri-pod) that will support a Skyliner 200P?

[RikM]

For visual use HEQ5, for imaging NEQ6. It is a little heavier and a fair bit longer than the Explorer 200P.

The nice thing about having a Dob is that you can just pick it up move a bit to avoid obstructions.

[Ganymede12]

Would an EQ 3-2 not suffice?

http://www.firstlightoptics.com/skywatcher-mounts/skywatcher-eq3-2-deluxe.html

[RikM]

No. An EQ3-2 can only just about handle an Explorer 150P. The Explorer 200P is a whole lot bigger than that and a Skyliner 200P is even bigger again than that.

[Ganymede12]

Fair enough.

So why is the HEQ5 better for visual and the NEQ6 better for imaging? What's the difference?

[Naemeth]

Would an EQ 3-2 not suffice?

http://www.firstligh...3-2-deluxe.html

I don't think an EQ3-2 would hold it without the mount wobbling or collapsing, there is a reason the standard 200p explorer is supplied with an EQ5. Better to get it on the Dob base now, and save up for a very sturdy mount in years to come .

[Ganymede12]

That's my plan

So why is the HEQ5 better for visual and the NEQ6 better for imaging? What's the difference?

[RikM]

For visual use you can get away with the mount being a bit less stable, so the HEQ5 would be fine. The NEQ6 would be more solid and stable all round, so would actually be 'better' all round, but it is a heavy lump and if you only planned to look through the scope, then you wouldn't need such a beast.

[Naemeth]

If you were ever planning for AP though, the NEQ-6 is fairly future proof. Safer bet than spending ~£700 on a HEQ-5 and then realising you want to do AP, and a NEQ-6 is ~£1000 I believe.

[Ganymede12]

The're both pretty expensive

I'm still going for a 200P though.

Could I buy a portable platform that would raise the dob higher so that it can see things closer to the horizon?

[estwing]

The're both pretty expensive

I'm still going for a 200P though.

Could I buy a portable platform that would raise the dob higher so that it can see things closer to the horizon?

no wait for it to get higher in the sky

[RikM]

I guess you could get a sturdy table or something and then use a step ladder to reach the eyepiece, but that kind of defeats the object of having a Dob. I find with mine that if an object is low enough that I can't see it with the Dob, then the air is usually all soupy and I wouldn't get a good view anyway. It is much better to view objects higher up because you have less atmospheric muck to look through.

[Naemeth]

The're both pretty expensive

I'm still going for a 200P though.

Could I buy a portable platform that would raise the dob higher so that it can see things closer to the horizon?

I don't see any need to buy one, you could probably use a stable wooden box or anything you have lying around that it can stand on. It just needs to be stable and solid enough to support the weight, so I wouldn't recommend cardboard .

[dtr42]

yip gotta agree closer to horizon your view can be pretty bad due to the atmosphere also in one post you say you cant see a lot below 25 degrees with a tripod [usually about 3-4 foot high extended ] so you would need a platform at least 5-6 foot high [your getting into piers at that height ]