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Enough said

Started by fblue, 07/10/2009 07:13PM
Posted 07/10/2009 07:13PM Opening Post
I have decided to let this whole thread go. I am in a no win situation here, no way to prove my points and no one is willing to grant my request to name a scope that meets the 1.2 criteria posted by Roland, to show what optics I am trying to compete with on this.

I guess that only the higher end brands of scopes are good enough for amateur photography and unless you are willing to pay huge amounts of money, your attempts are futile. wink

No disrespect was intended in any of my posts, just my attempts at trying to get the facts about the situation.

[SIZE="Large"][/SIZE][COLOR="Blue"][/COLOR] Floyd Blue grin
Amateur Imager
Posted 07/10/2009 08:21PM #1
Floyd the post you originally wrote was fine and made a good argument that Chinese instruments are good enough for most. I've seen these kind of post's escalate like this one did where now economics in the US and China are being discussed and I can definitely see the reason why. What's happened is that 90% of the forum post's are being written by a handful of Astromart users and most of them have pretty nice stuff and definitely have an opinion. Enjoy your equipment!

Clear skies, Martin

"In the beginner's mind there are many possibilities, but in the expert's there are few." Shunryu Suzuki[COLOR="Blue"][/COLOR]
Posted 07/12/2009 04:07AM #2
Floyd Blue said:


I guess that only the higher end brands of scopes are good enough for amateur photography and unless you are willing to pay huge amounts of money, your attempts are futile. wink


That is most ASSUREDLY not the case...and I don't believe that was bein' suggested. If somebody _was_ suggestin' that, they was DEAD WRONG.

Uncle Rod

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Waste it with Uncle Rod's Astro Blog!

http://uncle-rods.blogspot.com/
Posted 07/14/2009 05:00AM #3
Hey Floyd,

My heart goes out to you. I read the other thread and was surprised such an off topic and aggressive comment was allowed to be posted and then continue. Your point is straightforward and what's more the success of the Chinese products proves your point in spades. Nothing like reality to clear up misunderstandings.

I would also like to know what that company is doing to help save the American worker. Seems to me they should be hiring more people to increase manufacturing and thereby walk the talk. Seems I recall a decade long backlog that needs some attention.

john
Posted 07/14/2009 10:03AM #4
name a scope that meets the 1.2 criteria posted by Roland

I think there is only a very weak connection between the
FWHM on images and optical quality. Some criteria like
1.2" makes almost no sense. The FWHM will mostly depend on
seeing conditions high in the atmosphere, mount tracking
accuracy, mount vibration, pixel size, tube currents,
and probably lastly optical quality. Provided the optics
are diffraction limited (Strehl ~80%) the image FWHM is
going to be determined by something else.

The best "image quality" usually results from setting the
pixel size to roughly the seeing FWHM (i.e. minimizing the
CCD read noise per resolution element). Hence, as a matter
of observer practice, you are not going to see many FWHM much
smaller than 1". Reasonable observer choices are going to set
the FWHM, not the optical quality.

Is there a correlation between use of high end equipment and
resulting small FWHM? Perhaps. But it is probably related
to an overall effort to push the image quality (best
locations, waiting for good seeing, solid high $ mounts, large
format CCDs, etc.). The $ spent on the OTA is probably
the smallest contributing factor.

Anyway, theres my personal (and professional) take on this.