First Light - LXD75 SN10

[martinss]

Hello everyone,

Having ummed and ahhed about what to buy as an upgrade to my current 8" newt, I settled on a Meade LXD75 SN10 which is a 10" Schmidt Newtonian on a GOTO mount (in case you didn't know already!).

To say it's a bit of a monster would be about right - it weighs a ton and looks like it means business.

Well, the weather forecast tonight looked promising (cloudy and a smidge windy) so I got setup at about 9pm and began the alignment process. This was not as easy as the instructions make out. Meade don't know I live with a restricted view of the sky and that it was a tad cloudy. Nonetheless, I completed a rough alignment and got down to some observing.

First off was the moon, as it was there, not far about the brewery and gagging to be looked at. So, using Autostar on the laptop, I plumbed in moon...and sure enough, the scope slewed round to the moon - it was a bit off, which was fine (I was only roughly polar aligned and did a dodgy 2 star alignment anyway!!)....the view was awesome - it was clean, crisp and wonderfully bright. So I plugged in the Phillips webcam using their VLounge software - wicked! Live views of the surface of the moon...complete with rubbish seeing. Had a little stroll around the moon like a kid in a toy shop until it went behind a chimney.

Next up was Jupiter...again Autostar was pretty spot on (remember the dodgy alignment earlier)...through the webcam it was a bright disk, but just as I was about to play with the exposure, it too disappeared from view.

Not to be put off, I thought I'd give M57 a go...Autostar went right to it. and the view through the EP was amazing....the stars had colour and even (dare I say it?) the Ring Nebula appeared to have a tiny bit of colour in it!

Very impressed at the sight of M57, I thought I'd find M31 (well, Autostar did at least) and take a butchers at that. As the scope slewed noisily (even in quiet mode) round to the fabled galaxy, the clouds rolled in for about half an hour, so I used this time to tidy away the webcam and make a cup of coffee.

Coming back after the clouds had moved off, I was dumbstruck by M31 (not ever having found it before because of location and weather issues!) in the Eye Piece....simply stunning.

Now, at this point, I dashed in doors to get my DSLR out and try to capture it. I did have varying success, but was beaten off by clouds again - and the wind was picking up a touch. Focus, as always with a DSLR is a bit of a hit and miss affair, and didn't manage to attain a decent focus for a decent shot. Hence why I've not posted it.

As time was ticking along and desperate to get a picture of something through my new baby, I slewed round to Deneb and got the shot below. It's a single 12 second exposure at ISO3200 with a 2x Barlow on the front of a Neodymium filter through the light cloud in between the big heavy 'blot everything out clouds'. I really pleased with it for a first light effort.

After that, I packed up and came in feeling very satisfied indeed.

A few notes on the LXD setup...firstly, the focuser (as is well known I believe), is pretty pants. It does the job pretty well for EPs, but for a DSLR? No - it doesn't cut the mustard. A lowprofile Moonlight should do the trick nicely. Also, it does not allow enough inward focus to attain any sort of focus in the DSLR without the use of a barlow which is not ideal if you image a lot.

Now, there has been talk on the net I've noticed about the LXD75 and the SN10 possibly being too big for it. Well, on my first go, with rough alignment and generally rushing things a bit, I did not find this to be so...there is a bit of wobble, but every large newt is going to wobble a little bit...plus it was perhaps too windy for serious imaging, but nonetheless, properly balanced on the mount and locking the mirror open for a few seconds to dampen any movement in the OTA as the mirror flips seems to have done the trick.

The Autostar Suite is pretty good I think, not having used any software like that before, but could be a little more intuitive to use. I've got a copy of RedShift 6 coming tomorrow (hopefully) and will give that a go and see if there is any difference in ease of use.

Just looking through the EPs at random stars, they appear to be pin sharp and positively glisten in the sky so I am looking forward to checking out some clusters soon as well as....well, everything I can over time!

Dew was a bit of a problem on the corrector plate. I did make a temporary dew shield out of some thick black paper, but that got damp and sagged so I took it off, but my wife's hairdrier put pay to any further problems...so a dew shield will be on the next shopping list...as well as some of the dew control tape things I know nothing about....

Using the laser collimator in the dark was very easy indeed and can see that I will be checking the collimation before every observing session. And, the resulting star test proved very positive in the inward and outward check, although did exposure the fact that the mirror needs a good cleaning!

My personal (fairly inexperienced) point of view of this scope is excellent if used patiently and it is balanced properly. Certainly not a grab and go scope (although I currently have no choice but to use it as such), it would certainly suit someone with reasonable experience and a place to put it! The Autostar Suite is very good, if a little 'backward' to use in certain instanced and could do with an overhaul. I thoroughly enjoyed this first light experience and look forward to getting to know this setup better in the coming months.

Thanks for reading and I hope we all get some proper clear nights soon!!

Martin

[Brinders]

Excellent review, Martin. I consiered the LXD75 10" when I purchased my Celestron C9.25 and EQ6 Pro earlier this year. I was put off by reports I had read (like you) of the focuser not being up to the job and possibly the SNT 10 being too heavy for the mount. Seems from your review that I needn't have worried. The other thing that put me off was the reported problems with collomation; it appears you have to collimate both the primary and secondary rarther than just the secondary as in the case of an SCT, but again from your report, you seem to have good collimation.

The attraction of the Meade is a lot of aperture on a goto mount at reasonable cost. All the best with your new scope and thanks for posting an enlightening review. :salute:

[The Warthog]

Congratulations on a great first light! A friend of mine had an SN10 which was a great scope for him, until he traded it in on a LB12. Good choice.

[Andrew*]

Great first light review, Martin,

I'm interested to know what the coma's like on a SN?

I believe it's at f/4, as opposed to your 8", which I assume is f/5 - do you notice a difference in optical quality?

Cheers

Andrew

[martinss]

Hi Everyone,

Thanks for your feedback about the SN10, glad you liked it. I'm not too techy minded so a light review suits me down to the ground!

Andrew, to answer your question about coma - to be honest, I didn't notice much, if any, when looking through the eye piece which was a Meade 25mm, but like I said in the review, things were rushed. I'll post a better review when the weather cheers up a bit and I'm not quite as keen to see as much as possible before getting down to some serious stuff.

On the image of Deneb I posted, there is some coma towards the edges of the image, but because the focuser does not give enough inward travel, I had to use a 2x barlow to gain focus, I would suggest that the small amount of coma would be from the barlow and not the OTA.

That said though, a more thorough evaluation would be needed, but again, to be honest, if I didn't see too much, if any, then it's a good thing!! The stars are absolutely pin sharp though - a sight to behold!

As for the 8" in comparison (yes it is f5)...not sure if it is a fair test as it is an inferior scope optically, but still pretty good. There is more coma than the SN10, yes, considerably but less since I moved the mirror up the OTA to compensate for the new focuser I put on it late last year. The stars in that are pin sharp too, but not as bright (for obvious reasons) as the SN10. It's for sale on e-bay with some images of it and some taken through it if you'd like the link. Here's a picture of the 8", and one taken through it:

Hope this helps!

Martin