Jump to content

Message from meade about LS 6 ACF


Gaze Away

Recommended Posts

Hi all, just a note to say that Meade have suggested that my scope is good on deep sky images. I quote.....

Hi Andrew,

The LS will work just great visually on deep sky objects as the optics are as you say quite good.

The issue with deep sky imaging is that there is no means of doing the requisite polar alignment for this sort of photo work. You can however do quick exposures of say the Moon and planets using a Meade Tele-Extender and a DSI or other camera of your choice. Exposure times on these sorts of objects are typically no more than a few seconds. Beyond this with any alt-azimuth mounted scope such as the LS you encounter an effect called field rotation. The usual cure for this is polar alignment, meaning the scope would need to be on a wedge or have a German Equatorial type of mounting.

Best Regards,

John Piper

Manager, E-Commerce

Meade Instruments Corp.

Just wanted to ask, as my scope is 6" would you all agree its powerfull enough for deep sky objects and if so then maybe its worth me getting a wedge ?????

im a newbie, I just thought this may interest some of you, thanks,

A.P

Link to comment
Share on other sites

From what I know about the LS6, the scope itself sounds pretty good. It's a smaller version of the newer ACF SCT's that Meade produce so it should have a flat. coma free field which is great but in imaging terms, it's the focal ratio that matters for DSO imaging, not aperture and unfortunately the focal ratio of the LS6 is f10 which is pretty slow. You'd need to buy a reducer for it to operate at a sensible speed.

I'm thinking that time you add a reducer and you may well want to get into guiding (I'm not sure if the LS6's mount has a guide port), the mount just won't be up to the job so if you're planning for the long term you want to look at taking the tube off of the the mount and putting it on an equatorial mount.

Tony..

Link to comment
Share on other sites

Meade appear to suggest it would be good visually on deep sky objects and yes, 6" is a good start for observing DSOs, but the bigger aperture the better.

However, they say that to image DSOs it needs a wedge, but they don't specifically say that with a wedge it will be good at imaging DSOs.

The aperture is fine for imaging DSOs, afterall it can be done with a camera lens or a 60mm scope, but the long focal length of your scope makes the focal ratio very slow (f10). ie. the object will appear larger (be more magnified) on the camera sensor and it will need long exposure, compared to a short focal length f5 scope (the f10 will need 4x the exposure time for the same brighness of image). You can get a f6.3 focal reducer which will help enormously.

Wedges are difficult to use and polar align, especially if you have to set it up each time. Also, is the scope compatable with a wedge, the handset needs to be told it's on a wedge.

In fact wedges aren't necessary for short exposures up to about 2mins depending on which was the scope is pointing in the sky. If you want to give imaging a crack with your scope, I would suggest getting a focal reducer first, instead of the wedge, and doing some 2min images. See how the scope tracks. Work on you image processing skills. And buy "every photon counts". It's really as good as everyone says.

(Whippy beat me to some of this!)

Link to comment
Share on other sites

Well im starting my imaging soon so I will keep you all posted.I was just interested to see what people thought about Meade's answer to my question. As you say does the handset know its a wedge. I think he was quite clever in his answer by saying the scope needs to be on a wedge or have a German Equatorial type of mounting!!!. looking on their site, they dont or dont look like they do a wedge to fit this scope.I have asked so we will see.

Regards A.P

Link to comment
Share on other sites

Meade have at least been honest. Always a good point as far as I am concerned.

A 6" scope will pick out a wide range of DSO's. The Alt/Az mount will give field rotation. Taking short exposure images and stacking them will be the way around the problem, at least to some extent.

Give it a go with a webcam type camera and see how well it comes out. That is the quickest way to seeing how well it all does. At this stage cost nothing other then time, you have everything.

A wedge may be a solution but wedges are costly. Will say not sure how good/bad any images you get with the present A;t/Az mount will be. It all depends on the alignment accuracy and the tracking accuracy and on something like an f/10 scope they both need to be very good.

Still more impressed that Meade answered and gave an honest statement of the scopes limitations.

Link to comment
Share on other sites

Hi ronin,

Yes they have been very helpful and I dont think from his answer that I can get a wedge or at least one that the scope will recognise.

Im very happy with the scope and as I slowly learn about imaging and the solar system it will be a great help. I'm just waiting for some cloudless skies to try out my new Revalation eyepieces and to start down the road of Imaging. Lots of sound advice and friendly people on the site....I love it.

Regards Andy

Link to comment
Share on other sites

Not sure about the LS range but on the older ETX offerings you told the scope that the mount was an equitorial (as would be when on a wedge) and that was it.

Will say that switching from Alt/Az to Equitorial was so bad that I had to press the reset option on the scope and start again. I couldn't "switch" from Eq to Alt/Az when I wanted to make the change.

Other then that there isn't as best I know anything to recognise.

Link to comment
Share on other sites

Thanks Ronin, I think I will just have to accept the fact that I cant switch from Alt to Eq. I will learn a bit more about imaging and then see if I can sort a way around it. I am however going to take a good look through the settings of the scope before I totally give up.

Regards Andy.

Link to comment
Share on other sites

Archived

This topic is now archived and is closed to further replies.

  • Recently Browsing   0 members

    • No registered users viewing this page.
×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue. By using this site, you agree to our Terms of Use.