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BerzerkerNerd
19-01-2006, 10:43 PM
Hello ice persons, Bintel will shortly have available the Johnsonian equatorial tracking platform for dobmen and women. Retail is supposed to be around $1100.
It sits under your dob. base and what i am guessing is that it may be suitable for some tracking and imaging ?
Does anyone know anything about this american platform? i had a look at the Johnosonian website at a few picky's and info but would like to know more. At $1100 i could easily buy an eq. mount that may track better for DSO's so am unsure, as always/perpetually circumspect.:help:

We are not alone...

BerzerkerNerd
19-01-2006, 10:48 PM
Oh #@&% This thread existed some time ago- but any new insight and advice welcome- nerdwerx

Starkler
19-01-2006, 11:23 PM
For $1100 you could not buy an eq mount new that would be heavy enough to carry a 10 or 12 inch newtonian well. With the eq mount you also loose the intuitive push-to and eyepiece position convenience factors.

I feel a lot of people consider eq mounts etc because of frustrations in tracking objects at high power due to poor movements in their dob.
Perhaps a bit of time and $100 spent on teflon sliders/ ebony star type laminate could be enough to satisfy.

BerzerkerNerd
19-01-2006, 11:28 PM
Thanks Starkler, Well, as in all things related to life compromise rears its head again. Base is fairly sorted, but am curious as to alignment of Johnsonian platform, i assume it is a simple level/ true north or polar align ??

iceman
20-01-2006, 05:52 AM
I've got an EQ platform, a custom made one from www.roundtableplatforms.com

It cost me about AU$700 thanks to expensive shipping costs from america.

I'm not sure about aligning the johnsonian, but for mine, yeh point it SOUTH and get it level. For visual stuff, that's about as accurate as you need it, and you can keep the object in the FoV for several minutes with some tweaking of the speed controls.

For planetary imaging, it's important to get it aligned more accurately so the object stays in the very small FOV for a long enough time.

For DSO imaging, i've found that the EQ platform is not smooth enough or accurate enough at this stage. But I haven't spent a lot of time on it.

It's great for widefield shots with a long exposure on a DSLR.

How big is the johnsonian? Will it support up to 16" dobs?

Roger Davis
20-01-2006, 08:46 AM
Why don't you just Google like the rest of us?
Type 6 will take up to 90lb (36kg) up to 12"
Type 5 will take up to 180lb (72kg) up to 16"

BerzerkerNerd
20-01-2006, 08:59 AM
Thanks iceman, round table platforms hey.- Will consider. Would you buy one again with hindsight? They are cheaper than the John. for sure. All i want to do is begin the long learning process of hobby imaging, starting with local system bodies. The type 5 John. at $990 US will take up to 16" dobs and 180 pounds, or roughly 86 Kg. The smaller and less expensive type 6 will handle up to a 12" scope. But that is all i know about them as yet.

BerzerkerNerd
20-01-2006, 09:53 AM
Also , how do you opt to power this device either at home or away, there are many options- is there an astronomy favourite or preference : push/pull and dial wind caveman, hope this isnt all old news to most members.I am new to forum, but not entirely to astronomy and navigation- so forgive me.