Skywatcher 250P Dob OTA on an HEQ5Pro mount?

[craigg]

Hi All,

Just a hypothetical question at this stage, but I currently have a SW 200P on an HEQ5 Pro mount.  I have used this with reasonable success for AP using DSLR and guide camera on the finder.  I've come across someone selling a SW 250P Dobsonian OTA and was wondering if anyone has experience with one of these on an HEQ5?  I have already got a counterweight extender bar but my concern is around the overall weight and I believe the dob versions are longer that the EQ OTA's.

Any thoughts/comments much appreciated.

Many thanks,

Craig

[Spikey]

For visual yes, for AP I wouldn't consider it. Too heavy, too big.

[Tinker1947]

Bit heavy for AP, stick with the 200P

[craigg]

OK, thanks.  Out interest, do you think it's too heavy because it's a dob OTA or is the 'regular' 250P too heavy?

[Tinker1947]

Its to heavy....

[brantuk]

I've used a ten inch on an NEQ6 and it struggled - too much vibration - under/over shooting objects - hard to balance effectively - useless in the lightest of breezes. I can only imaging these type of probs will be worse still using an HEQ5. Hth

[tich]

I'd imagine if it were used with the HEQ5 then it would struggle although I do use one to image with on an NEQ6 & had no issues with it apart from when its breezy but then most Newts act like sails anyway.

The Crab Nebula by tich_dude, on Flickr

[craigg]

Nice setup tich.  The NEQ6 is a fair bit more stable from the ones I've seen out in dark fields at night.  I think I'll stick with the 200P for now.  

[Jonk]

I have a 250p-ds and have used for AP on an AZ-EQ6.

Although not perfect, it was ok for practising.

It's ok for visual on an HEQ5 pro, but I agree it's too heavy for AP.

[ollypenrice]

Nothing is worse than being under-mounted in AP. I would consider your present setup to be on the marginal side so I would never try to push it further.

What would be the advantage? There's no great difference in focal length and optical resolution is unlikely to be what limits your final image resolution. (This will be down to guiding and seeing in all probability.)

Olly

[craigg]

Nothing is worse than being under-mounted in AP. I would consider your present setup to be on the marginal side so I would never try to push it further.

What would be the advantage? There's no great difference in focal length and optical resolution is unlikely to be what limits your final image resolution. (This will be down to guiding and seeing in all probability.)

Olly

Yes, sounds like it wouldn't be the best return on the investment (gotta think of these things in this game, unless very well-to-do).  Maybe I'll put the money into the astro camera fund instead.

Thanks again for all the feedback folks, much appreciated.

[zicklurky]

If you're doing planetary or lunar imaging you may be OK. It's not ideal, but I use a C11 on my heq5 and it does just fine. DSO imaging you will probably struggle though.

[Tinker1947]

You might get away with one of these  there around 4Kg lighter, choose a 1/10 wave mirror for AP.....or the 8" would be lighter still.....

http://www.orionoptics.co.uk/VX/vx10-10l.html

[phil125]

I use my Orion Optics Europa 250 on a HEQ5. For visual you can get away with it, but it does move around a bit when focusing. I have not even tried for any imaging, I'm sure it won't be steady, plus putting a DSLR in the focuser seems too much. I have though you might get away with a webcam for some planetary imaging - its on my to-do list. I think my Europa is a few Kg lighter than your SW though.

[craigg]

Interesting.  HEQ5 Pro load limit is 16Kg, I'm assuming that doesn't include counter-weights, with 2x 5Kg weights that would put the standard  HEQ5/200P setup overweight straight off the shelf?  My flocked 200P with rings, finder, Tetrad, and motor focuser weigh in at 11Kg (just weighed it with a luggage scale).  Add the SLR and guide camera we'll be approaching 12Kg, so comfortably within the 16Kg load limit.  With this setup, providing i take care to balance both axis, i have no problem with long exposure AP.

Phil125 - the VX10 with rings and finder are 11Kg, so you're right, with all the same things added it would be only marginally heavier than the 200P.