Posts Made By: Charles Peterson

Keith Lawson said:

I just got a Meade 178 ED a couple of days ago. I have had many refractors over the years but this was my first APO! What a beautiful beast Put everything together on the evening of the 21st. First light revealed the dreaded comatic star image in the center of the field of view in a medium power eyepiece (160x). I had made sure the lens and focuser were aligned earlier so this was not the problem. I had seen this in other refractors before. Looks like the lens elements had shifted during rough shipment. Crap :C Well..... I dreaded a trip to Meade (wait, wait, wait) and did not want to return the instrument after finally finding one in excellent shape. After getting over my initial dissapointment I found a way to fix it and I'm now having a ball. Second light was a blast. Textbook star images 8) Mars was "off the hook" at 320x The tiny polar cap was easily visable during moments of steady seeing. This 50 year old man was laughing like a little kid on a new bike!

I found that the collimatable lens cell has a collimation setup for the second element. It's tricky to use but it works. It's a lot like trying to collimate a Chromacor which can be a pain but this took me about 20 minutes using my daytime artificial star. Last nights tests confirmed about a 1/6th to 1/7th wave overall correction (ronchi[250 line grating] & star test). I pushed the instrument to 426x (Antares 7.5 & barlow)and the image remained crisp and well detailed. Not bad at all I'm glad I was able to fix it "in house". My question is: Has anyone else had the same expererience?

Keith

Darian Rachal said:

Is there any company making quality 'planetary' newtonians? I believe Starsplitter once made a 6"F9(?) Dob optimized for planet observing.