Last update 99-6-25

Experiences with the Meade LX10, part 2


LX10


98-6-20 Today I had I look to my LX10 hand controller. For people who want to make there own hand controller or who want to connect an electronic guider via a relay, here is a sketch of the electronic circuit:


electronic circuit of the lx10 hand controller.


98-6-21. Last month, at the yearly astronomy market (Astronomie boerse in Bockmoehle) here in Germany, I bought an focal reducer from Celestron and a JMB visual Sun filter for my ETX. Today the sky was reasonably clear and had some time to play with it. The Sun showed some nice sun spots but what is the environment light bright !. I felt like a night animal suddenly awakened in the middle of the day. At one moment I used a towel to cover my head and telescope to keep the bright light away. I made some direct focus slides. I also tried to make some slides using eye-pc projection, however I could not focus due to the bright day light. At the end if this hot day, the wetter turned cloudy again, so I have to wait again.

I bought an Sun filter for the ETX and not LX10 due to the fact, that in the heat of the SUN the performance of a large (standard) telescope is not much better then a small one. Secondly the ETX is nice transportable telescope and a filter for the ETX is cheaper then one for the LX10.


98-6-25 New LX10 photos, made from my garden in Bruehl (50.000 inhabitants):

Galaxy M51:


M51 from garden

M13 from my garden:


M13 from garden

M57 from my garden. Small but clearly visible on the right side of this slide:


M57 from garden

My LX10:

LX10 at home

The Celestron off-axis guider: This picture show clearly the small prisma:

Celestron off-axis guider

98-10-11 A month ago I bought an 2 inch eyepc and a 2 inch diagonal mirror. The eyepc was not an original 2 inch but surplus from disassembled Russian optical equipment. It was machined a little down till 2 inch , so it fits in a 2 inch slot. A nice 5 ? element design focal length 33 mm with a view of about 76 or 70 degrees.

The view is marvellous. It is like looking trough a window of a spaceship. The field is wider then my Meade 40 mm ploessl. I can recommend these type of eyepc's to everybody. Get a 2 inch wide field instead of the standard 1,25 inch ploessl peepholes.

Here are some photo examples of one of the seldom clear/cloudless nights. This time I used an standard negative film the Fuji Superia 400 asa. The results of the deepsky shots where not so good. Maybe due to the low position of M8/M20 but the result of Saturn, Jupiter are not bad.


jupa9-98.jpg


sata9-98.jpg


moona998.jpg


moonb998.jpg

Comparison between the LX10 and ETX telescopes:

Comparison between the LX10 and ETX. In general. After using the LX10 and the ETX, my impression is that an 8 inch telescope gives only 1,5 better views then a 3,5 inch. It becomes more and more critical to have a stable atmosphere and also the telescope is reaching the maximum resolution the atmosphere on Earth is allowing. This limit is under the best conditions about 0,5 arc seconds. This limit will be reached under very very good conditions (not here). The big advantage of the LX10 is it relatively stable drive. This allows to make astro photo's with an additional guider. The amount of light (focal ratio = 10) is just enough to make deepsky photo's within 10 or 30 minutes, but gives also enough magnification for observing planets. The ETX is nice for viewing but the amount of light (focal ratio 13,8 plus losses aluminized spot) is not enough to get something on film. The drive of the ETX is humming too much to make photo's with an exposure time longer then 5 or 10 seconds. For long exposures a stable worm drive like the one in the LX10 telescope is essential. The ETX is ideal for visual observing and mobile work.


So here some example of pictures made with a standard negative film, Fuji Superia 400 asa. They where made from my window un a urban area:

m42-9811.jpgm27-9811.jpghorse991.jpg

Here is a picture of Mars made with the LX10. It is the best result of a few clear days. The biggest problem is to have a stable atmosphere. Most days, the atmosphere/air is just to unstable. During the bad days, you I could recognize that mars is a planet and not a point source, but it looked like somebody was holding a candle just below the front of mine telescope:

Focus tool for telescopes: There are several tools for finding the focus on the market. They all consist of a telescope cover with two, maybe three holes. I found out that an ordinair piece of paper, A4 size will do exactly the same. I just fold the paper till the width is about 2/3 (smaller holes seems to work better) of the telescope diameter. The length should be more then the telescope diameter. Then I bend a small part and hang it vertical in the front of the telescope. Any de-focussing will result in a nice double view of stars and planets ! (post note, later I used a 3 holes contruction see lx10_5) Here a small illustration sketch:

focus.gif