Viewing the moon with a Meade LPI

[Chris Stacey]

I wasn't sure where to put this so I apologise if it's the wrong section.

I thought I'd have a go and looking at the moon through a Meade LPI, (maybe take the occasional image.) Set it up today, lined it up to a few trees about 200 yrds away and got a lovely piucture on my laptop screen. I went out this evening, lined up the moon in the dob, focused, changed the ep for the lpi and......nothing! Just a big unfocused blob on the screen. I had a clear outline of the moon but no detail or discernible image to speak of. I played around with some settings, played around with the focus on the scope but nothing.

Any ideas what I'm doing wrong (apart from buying it to begin with ), far short of a quick modification with a claw hammer I'm at a lose at what to do?

[barkis]

Unless you have the eyepiece you used to focus the scope parfocal with the LPI, then you will not get a focused image.

Does the software not allow you to use a focus mode whereby the camera keeps taking images until you stop it. This allows you to tweak the focus until it is spot on. Once you have it focused to your liking, lock your focuser in position, then carefully remove the camera. Put your eyepiece into the focuser, and without moving the focuser itself, slide the eyepiece in and out to find the focus, once you have it, you should have a ring that should fit the eyepiece barrel. This ring should be positioned against the focuser. IE, buttet up against it, then a screw in the ring tightened onto the eypiece barrel.

That eyepiece can be used to focus your camear in future, as long as the parfocal ring is left locked in place.

I hope I have explained that in a way you can understand it Chris.

Ron.

[Chris Stacey]

You have Ron, thank you. I wondered what the ring was for, that makes sense now.

I'm using the software it came with. When you click on the telescope tab it has focus buttons but when I clicked on them it came up with a message about not being connected to the scope (or something similiar). Looking at it again I'm wondering if accidentally hit the connect button and not the focus button.

Cheers Ron, you've given me something to try now.

[Mel]

Hi Chris,

Hope you dont mind me adding my four penn'th, but I started out with the LPI on my ETX - it's not the easiest bit of kit to use, particularly the Meade Envisage software. I haven't used it much lately, but here are some tips from the back of my mind.

1. Make an eyepiece parfocal as suggested above. It really helps to be near focus when you start. I think I used a 26mm as suggested in the manual.

2. As soon as you drop the camera in, centre the image then hit the auto exposure tick box (I think its a tick box, it may be a button). This puts the software into a loop where it samples the image at different exposures up to 1s and picks the best one for the brightness of the target. Since you may be imaging targets ranging in brightness from the Moon to Mars, the exposure required varies enormously.

3. Play with the contrast controls. Once a reasonable exposure is chosen by the software, dont change it, but rather move the two sliders representing the contrast of the image. You should start with the Auto box ticked, but when you move one of the sliders, it will automatically untick. Usually I found moving one of them by just a small amount improved the image drastically. Once this was done, you can change the exposure setting and try it all again. You can also play with the gain to see if that helps the adjustments.

4. Remember to draw a box round a dark feature so the software has a reference point to stack the frames. I would recomend saving as TIFF if you have the disk space, and save all frames so you can restack at a later date with Registax which usually does a better job than the Meade software.

Hope that helps you.

Iain

[Chris Stacey]

Thanks Iain,

I don't appear to have a manual, all I know about the LPI is what I found on-line on Meades main page about it, hence I didn't know about parfocal. I've just been playing around and seeing what happens. Because I got a nice crisp image in daylight of trees a few hundred yards away I assumed it would be that easy when viewing the moon, I was mistaken. I still think I'm missing something though, I used my electric focuser to run through the whole focus range slowly as well as playing with the contrast controls but still no joy - just a big white unfocused blob.

I'll try again tonight, weather permitting.

Thanks for your advice, all tips are welcome

Edit - found the manual, it's on the disk. D'oh.

[Mel]

Hello again,

Stick at it, I remember my first few outings with the LPI as nothing more than exercises in frustration, but I did eventually begin to get to grips with it and also understand it's limitations.

The 'manual' is just a PDF which you can download from Meade:

http://www.meade.com/manuals/TelescopeManuals/LPI_Imager/LPI_Manual.pdf

Have fun.

Iain