Posts Made By: Greg Nowell

I just read the "New Apos" thread and was struck that maybe many of the threads in this particular sub-forum should be moved down to "religion."

(I do own two refractors)

OK, that's all....

(ducking and covering and running out the door)

GN

I feel a bit naked doing this but I thought I would put OMI's specs on the mirror I just purchased (used) up for review:

http://tinyurl.com/yele62q

The link takes you to a pdf of the report (or at least it should). This is a ten inch f/6. My take is there is some TDE but maybe not enough to bother worrying about. I have read it is difficult to eliminate. Club members who look at these things say they are puzzled by the number of lines in the interferometer report, that usually there are fewer lines.

The Strehl of .96 looks pretty good to me, I don't know what to make of the RMS and I don't know how to translate this into "wavefront error" etc.

I'm sure a lot of people here can read this in their sleep.

OMI puts all its mirror reports on the 'net which I think is a great commitment, helps prevent the kind of nonsense that Dick Nelson did with Optical Craftsmen back in the 60s (all of that is in two threads lower down).

I'm hopeful that this is a very very good mirror without necessarily being the peak of the peak. I bought it here on the 'mart and got a good price.

OMI has a good relationship with Obsession and is one of the more conspicuous names in the upper end market these days, I think possibly with higher output than some of the other zen masters. Some people may for that reason feel shy about posting a critical opinion, so PM me if you want to say something private. But as y'all may gather from my having posted the Optical Craftsmen Foucault, I'm pretty hang loose. Things are what they are.

regards
Greg N

OMI has the remarkable and laudable policy of posting test information on every mirror it sells, including interferograms. I just bought an OMI 10" f/6.

I posted the link to the test report and a request for help reading it in EQUIPMENT and I would be grateful if a few of the folks here who are smarter than me (of which there are many) would be so kind as to stroll up to EQUIPMENT and help me read/understand the report.

I won't say more as I'd like to push the discussion North into equipment. I probably should have chosen REFLECTORS but I did what I did.

thanks
Greg N

I'm curious to know whether anyone in this vast hobby of ours has taken three or four Chinese mirrors and subjected them to rigorous analysis. I'm thinking of interferograms not in the field, but I guess in the field counts too.

I'm just wondering, in effect, whether we know that investing in a U.S. premium make really does deliver a noticeable improvement in quality.

I'm really, however, more after DATA than opinions.

thanks Greg N

This finder "made in Japan" was on my recently acquired Optical Craftsmen 1968 vintage. To me it looks more recent than 1968--Optical Craftsmen's finders were, I think, black and white.

But I'm not sure. This is a very nice finder with rear focus which you don't see every day. Seems more similar to my Tak finder than anything else. But it's not illuminated.

I did check the objective but didn't see a name. I will try looking more closely.

were products sometimes marketed here just as "made in Japan"?

Greg N

Does anyone recognize the circle emblem on this finder? It seems that a number of Japanese vendors in mid to late 20th c optics used a circle type emblem. This one is kind of like a peace symbol except the middle leg is missing, so the circle is divided into three equal parts.



thanks

Greg N

http://www.astromart.com/common/image_popup.asp?image=/images/forums/687000-687999/687768.jpg

The above link is to a picture posted in EYEPIECES, where I am trying to identify to which Japanese company the circle emblem is attached.

My question to the Newt mavens here: I have a Moonlite 2" focuser on the way for this OTA, is this a recipe for head banging? The finder looks very close to the focuser.

thanks
Greg N

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Lawrence Aldrich said:

The tip off for me is the "loose lenses" comment...this is a common complaint among inexperienced buyers of even new widefield eyepieces, and is of little or no consequence.

I'm rescuing this eyepiece comment from the terminating fraud thread.

That's just y'all Televue rattle people. XWs are waterproof and they don't rattle. If they do rattle they ain't waterproof so there's an issue. Not EVERYONE should be expecting a rattle.

I think that the expect-a-rattle thing is really a comment on an area where Televue cuts some corners. I would expect that an Explore Scientific 100 degree wouldn't rattle either, if it is in fact waterproof.


Greg N

On vacation at the California Academy of Arts and Sciences (natural history museum) with a big honkin' T-rex reconstruction near the entrance.

Got into a friendly debate with my friend about whether a .45, properly aimed, could stop a t-rex.

Thoughts?

Greg N

I had a very nice Nikon coolpix 995 that I scored off ebay for $200 a few years ago and took a few thousand pictures with. It also took movies with no sound.

This camera appears to have died. It no longer takes movies and the focus has stopped functioning on the stills.

Although I used it to take some pictures of the moon, this has been a general purpose camera for putting items for sale up on the 'mart and taking family pictures etc.

I am hoping that people here will be able to give me some recommendations for good quality used models that I might look for on the mart or on the bay for around $200, on the theory that a well-recommended used model in that price range will be better than a a brand new $150 to $200 whatever camera.

thanks

Greg N