Do I need a wedge for Meade 14"

[tooth_dr]

I need some advice regarding a 14" scope.  If this is going to be used for public use, in an observatory, mostly just with a camera to give live images on a screen, do you need a wedge?  It wont be used for long exposure imaging.  Is there any advantages to fitting a wedge?

 

Thanks in advance.

 

[Cosmic Geoff]

1 hour ago, tooth_dr said:

Is there any advantages to fitting a wedge?

Future proofing.

I have seen the 16" LX200 Meade at the Open University observatory, and that sits on a wedge.

[tooth_dr]

2 minutes ago, Cosmic Geoff said:

Future proofing.

I have seen the 16" LX200 Meade at the Open University observatory, and that sits on a wedge.

Thanks Geoff.  In term of future proofing - is this solely for deepsky imaging with long exposures?  I'm just trying to rationalise the spending versus what benefits it brings.  It would raise the overall height of the scope for viewing too - not sure if this is an advantage or disadvantage?

[Cosmic Geoff]

6 minutes ago, tooth_dr said:

In term of future proofing - is this solely for deepsky imaging with long exposures?  I'm just trying to rationalise the spending versus what benefits it brings.  It would raise the overall height of the scope for viewing too - not sure if this is an advantage or disadvantage?

I was thinking of the deepsky imaging with long exposures option.  IIRC the eyepiece height of the OU instrument is suited to standing observers - a bit high for a child.  The wedge is triangular (a fixed welded sub-frame) and I don't think removing it would make the instrument significantly lower.

[tooth_dr]

1 minute ago, Cosmic Geoff said:

I was thinking of the deepsky imaging with long exposures option.  IIRC the eyepiece height of the OU instrument is suited to standing observers - a bit high for a child.  The wedge is triangular (a fixed welded sub-frame) and I don't think removing it would make the instrument significantly lower.

Thanks Geoff.  I doubt it will ever be used for deep sky stuff, but you know what, it's better to have it for sure!

[Davey-T]

For visual and live video it's better on alt / az , also more accurate, at least mine was, the GoTo was always spot on, not so good on the wedge, it can be a bit tricky aiming / viewing straight up in alt/az.

Long exposure imaging is possible but took a bit of fetlling of the gears etc and needs a custom balance system and OAG, my 10" can do up to 30 minutes depending on where I'm aiming but usually only do 10 minutes due to local light pollution.

There are many scare stories on tinternet about the Meade wedge caused by the original design with plastic gears, later mounts have different design of motor mounting /gears but people still keep repeating the original problems as a reason not to buy one.

Theoretically at least a wedge fork mount should be a much better thing than an EQ mount especially for bigger scopes.

Dave

 

Edited September 20, 2019 by Davey-T

[tooth_dr]

@Davey-T thanks the the reply. Although I’ve used much smaller alt as mounts, this looks like a different league in terms of size!

[Cosmic Geoff]

An equatorial mount (wedge) will get any images in the correct RA/Dec orientation, which may be a consideration for your purpose.

I took an image of the 'africano' comet with an alt-az mount and it is skewed by about 45 deg which made the image harder to interpret.

[Davey-T]

27 minutes ago, Cosmic Geoff said:

I took an image of the 'africano' comet with an alt-az mount and it is skewed by about 45 deg which made the image harder to interpret.

Doing a time lapse of it the other night and had to start in the centre of the frame because I couldn't figure out which way it was going to go 😂

Dave

[baggywrinkle]

If it is just for visual and video but not astro - photography I would stick with the AZ mount.

I have the LX850 12" SCT and that is a beast, I've seen the 14" OTA at Norwich Astro Soc' and then realised I had made the right choice for my home obsy.

[Louis D]

Alt-Az tends to be more stable on consumer grade mounts.  Many wedges are not sturdy enough and tend to add another place for vibration to emanate from during visual observations leading to longer settling times after focusing or someone bumping the eyepiece.

[Cosmic Geoff]

The wedge seems to be getting the thumbs-down here. As an engineer, I can appreciate that using a wedge could add more stress to a consumer-grade mount.  Perhaps the best answer is to mount it as an alt-az but design the setup/pier so that a wedge can be added later if desired.

The wedge for the OU LX200 telescope is a fixed one, apparently welded up from angle iron.

[tooth_dr]

13 minutes ago, Cosmic Geoff said:

The wedge seems to be getting the thumbs-down here. As an engineer, I can appreciate that using a wedge could add more stress to a consumer-grade mount.  Perhaps the best answer is to mount it as an alt-az but design the setup/pier so that a wedge can be added later if desired.

The wedge for the OU LX200 telescope is a fixed one, apparently welded up from angle iron.

I will hopefully have access to this scope so I guess there is the potential for doing some nice deep sky imaging myself! I think having the option to use it or not is sensible. 

[tooth_dr]

Thanks to everyone who contributed to the thread. @Cosmic Geoff @Davey-T @baggywrinkle @Louis D 👍🏼