Further question on Losmandy Plate and ed120 scope

[Carl]

Any chance of a fast reply appreciated.
Thanks for all of your replies before but i think i have missled everyone with the wrong question so i'll try again.

What concerns me is the bowing effect of a scope and how that bowing effects an image.

Scope: Skywatcher ed120 APO
Mount: Skywatcher EQ6 Wide 'D' style mount
Camera on back of scope: Canon 500d plus field flattener ect.

I currently have an ADM Losmandy D style Universal plate 11" long 4" wide. When i attach the scope rings the distance between rings is 8".

On top of the rings i have a mini dovetail plate attached. This screws on and secures to the main scope rings, forming a rigid assembly. The mini dovetail only supports a modified 9x50 finder/guidescope using an Orion auto guidercamera (very light).

Flexure between guiding and imaging scope was not an issue when imaging with an 80ed refractor.

So my question i think, should have been the following:
Taking into consideration weight at the front and back of the ed120 do i need a longer base plate to avoid bowing the scope? Or am i being an absolute tool and worrying over nothing?

Regards
Carl

[Poita]

I'd say worrying over nothing, but just to be sure, how long is the ED120? Take a picture of your setup so we can get a look.
I have a longer losmandy plate sitting on the shelf here if it worries you overmuch.

[Carl]

Hi Peter
All up it would be about 1000mm when you extend the focuser and add the camera. Thank's for the offer on the Losmandy plate, how wide is it and how much do you want for it?

Regards
carl

[adman]

Hi Carl, with that setup, the scope mounting is not going to be a significant source of flexure. The places you want to pay attention to are the focuser and the camera attachment as both of these can move slightly as the scope moves when tracking an object. If you are guiding, then any relative movement of the imaging scope and guide scope can give you problems as well.

At your focal length which is less than a metre, it will be reasonably forgiving. Have you taken any images with this setup yet which you think might show some flexure happening? The rule here is if it ain't broke don't fix it. Worry about flexure if you are getting it, but if you are getting good images, then don't spend money chasing problems that might not exist.

Adam

[Poita]

You shouldn't be getting any 'bowing' with your current setup.
Give it a go and see if you get any flex related issues.

[Carl]

Thanks everyone for your advice
You're right, set it up and see how it goes.

Merry Christmas to you all