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Old Jul 9, 2003, 7:51 AM   #1
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Default CP 4500 ordered and looking for spotting scope suggestions.

I sold my F707 and my CP 4500 will be delivered Monday. I am leaning towards the ETX 90 and Williams eyepiece but wanted to get some other suggestions. Can anyone suggest a combination (scope, eyepiece, adapter) , that would fall in the $400 -$450 range.

I am not very clear on how much magnification the Meade ETX 90 is going to give or what I really need. My main use is going to be wildlife, mostly deer and birds. I might also use the setup for investigation purposes where I might need an image that would clearly identify a person at 100-200 yards away. Would the Meade do this or would it be to much magnification or not enough?

Of course I want a quality image, as little vignetting as possible throughout zoom range and portability would be nice. Thats one thing I noticed the ETX 90 might be somewhat cumbersome compared to an actual spotting scope.

Thanks for any input.
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Old Jul 9, 2003, 7:59 AM   #2
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I was looking into the magnification question myself just few days ago. I saw that Lin had posted an image or two using the ETX 90 which was around 2000mm and the other was about 5000mm. I'd like to think that is enough magnification for the job!

How dry is the air where you live? A problem can be that you are taking the picture through so much air that things like moisture and heat can effect the quality of the picture.

My bet, althought I could be wrong, is that the combination you name might be the only thing which keeps you in that price range you name. I am rather ignorant in what works and doesn't... but from the comments I've seen posted here, that is consistantly the combination which is mentioned.

Eric
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Old Jul 9, 2003, 12:33 PM   #3
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Quote:
Originally Posted by eric s
My bet, althought I could be wrong, is that the combination you name might be the only thing which keeps you in that price range you name. I am rather ignorant in what works and doesn't... but from the comments I've seen posted here, that is consistantly the combination which is mentioned.

Eric
Your most likely correct. I was really just looking for a little more portability, even it meant sacrificing some magnification, if I can afford to sacrifice it. I have no idea what I need only what I need it to do.
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Old Jul 9, 2003, 2:40 PM   #4
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You could look into asking on the digiscoping forum/group at yahoo. I have heard good things about it, but I've never read it. In some ways, thought... the problem is that they are so good there I wouldn't be surprised if they just don't have experience with the cheaper setups. I bet most use Swarovski, Lecia and other top-of-the-line spotting scopes.

Eric
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Old Jul 11, 2003, 11:43 PM   #5
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I am not very clear on how much magnification the Meade ETX 90 is going to give
Three factors determine magnification. First, the inherent combination of the fixed focal length tube of the telescope, then the focal length of the eyepiece, and finally the amount of zoom and focal length of the camera being used.

With the CP4500 you start with an effective 38mm wide and zoom to 155mm telephoto. The Meade ETX-90 has a fixed focal length of 1250mm at F13.8. When you add an eyepiece you determine the overall "power" of the scope itself. For example, adding a 24mm eyepiece would give you a total of 52.083x (1250/24). At the full wide angle of your CP4500 (38mm) you would then have a focal length with this scope and eyepiece of 1979.04mm (38mm times 52.08x). At the full telephoto of 155mm you will have 8072.86mm (155mm x 52.083x).

In between these values of full wide angle to full telephoto you will have to convert the focal length reported by the EXIF file to 35mm equivalent then use that to multiply by the "power factor" of 52.0833 to get the equivalent focal length for the particular shot.

In practice, you can shoot in good lighting up to about 6,000mm with excellent results. So with the 24mm eyepiece, you would not use the full 4x zoom on the CP4500. To adjust the entire spectrum of focal lengths downward, you would choose an eyepiece of longer focal length.

For example, let's say you were to choose a 40mm eyepiece - let's do the math:

1250/40=31.25x (this is the "power factor" with the Meade and a 40mm eyepiece). Then multiplying the 38mm wide angle by 31.25 you have 1187.5mm at the wide angle end. For the full telephoto you would multiply 155mm times 31.25x = 4843.75mm.

Personally, I use the CP4500 with both my Swarovski ST-80HD and Meade ETX-90 with a William Optics 24mm eyepiece.

Lin
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Old Jul 12, 2003, 12:02 AM   #6
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Your most likely correct. I was really just looking for a little more portability, even it meant sacrificing some magnification, if I can afford to sacrifice it. I have no idea what I need only what I need it to do.
There is not a lot of difference in the "portability" of the Meade versus the various spotting scopes, but there is a difference in ruggedness and weatherproofing.

The Meade is a precision instrument, but because it uses a mirror objective, there are inherent advantages as well as disadvantages. For pure image quality in digiscoping, it's difficult to beat the Meade ETX-90. I see little or no differences between my $1600 Swarovski and my $199 Meade as far as image quality is concerned. The Swarovski, however, is waterproof, dust proof, built like a tank and can take a hell of a lick and still function perfectly. The Meade is much more delicate, is not weatherproof or shock proof and is not nearly as rugged as the Swarovski. But in all fairness, the spotting scope you are looking at for $199 is most assuredly NOT going to have the image quality of the Meade ETX-90. It just costs WAY too much to make ED (APO) glass. This $199 scope does NOT have corrected glass and I guarantee you that it will induce chromatic aberration. The "least" expensive true quality terrestrial spotting scopes of non mirror design will set you back about $1000 at the best available prices. The least expensive one which I would consider at all is the Pentax 80.

You really need to decide whether you need image quality and light gathering (90mm) or an inexpensive and assuredly mediocre spotting scope. The old saying "there ain't no free lunch" is generally true. The Meade ETX-90 is truly an exception to this general rule. It used to cost $500-600 and was a bargain at that price. The barrel is easily separated from the yoke assembly and has its own tripod mounting access. It's quite lilght (aluminum construction) and extremely good from the optics perspective. Mirrors can't cause chromatic aberrations so only the eyepiece quality is an issue. The $199 terrestrial spotting scope you are considering does not have APO corrected glass so it absolutely will induce chromatic aberration. The CP4500 has a bit of CA itself, so the combination will be worse.

It's a situation of an unknown versus a known good digiscoping combination. Here are two images I like to use as samples simply because they demonstarate the extremes from about 2000mm to 6000mm (5989mm precisely). These were taken with my Meade and CP990 before I bought the CP4500. The Robin was at about 2000mm and the Starling at 5989mm.


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Old Jul 12, 2003, 8:55 PM   #7
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Default Thanks for the infor

I really appreciate all the feedback. I did order the Meade 90. Should be here this week. Although I should not, and the wife is going to have a fit, I am ordering the Eagle Eye 5x.
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