EagleEye?

[ytreland]

I bought a "EagleEye OpticZoom 5 X" earlier to use on my Kodak dc280, I have now sold my Kodak (but not the lens) and bought a Canon G2, but when I try to use the Zoom with my Canon I get a "Lens alarm" does that mean I can not use it, or is there a way around it so I can use it?
Thank's in advance for any help.

[Hyun]

Have you checked the G2's manual to see what the error means? Maybe it has nothing to do with the EagleEye.

Anyway, you can always check out the EagleEye website--they do tell you exactly what you'll need to attach the 5x teleconverter to your camera:

http://www.eagleeyeuk.com/what_do_I_need.htm

[steve]

With any camera that has a lens that extends during powerup you must make sure that anything you mount on it will not impede the lens extension. There are specially made tube adapters for the G1, G2, G3 etc that allow other lenses to be put on them safely.

See my G2 review, we list some lens adapters:

http://www.steves-digicams.com/2001_reviews/g2_pg2.html

Another consideration is that those monocular tele adapter lenses only work with certain focal length zoom lenses. It's best to check the EagleEye home page for the list of recommended cameras it can be used with.


-Steve

[Lin Evans]

Good advice from Steve - The OpticZoom 5x isn't a good match for the Canon. Large lens cameras in general don't do well with higher powered teleconverters like the 5x. There will be significant vignetting (black fringe around the periphery) even at full zoom. My suggestion would be to go with a good 1.7x like the Olympus B-300 or the new TCON-17 (same essential lens). Trying to get 5x on the Canons is not really practical.

Lin

[shene]

Originally Posted by Lin Evans

Large lens cameras in general don't do well with higher powered teleconverters like the 5x. There will be significant vignetting (black fringe around the periphery) even at full zoom.

Well, this is actually not exactly the reason. As long as the view angle of the on-camera lens is contained in the exiting ray bundle of the monoscope, no vignetting will occur. It does not matter if the on-camera lens is a large zoom or not. Just mount a 2X or even 1.5X teleconverter when the camera is zoomed all the way out to the wide end, and you will see vignetting due to the above reason. Generally speaking, monoscopes such as the EagleEye 5X, CrystalVue 8X and Kenko 6X and 8X have small rear elements and thread size. To mount it on a larger diameter lenses such as the Sony 717, Nikon 5700 and Minolta 7i, one or more step-rings are required. As a result, the on-camera lens sees the step-down rings and/or the surrounding ring of the rear panel of the monoscope. This is the major cause of vignetting when using a monoscope.

CK
http://www.cs.mtu.edu/~shene/DigiCam
Nikon Coolpix 950/990/995/2500/4500 user guide

[shene]

Sorry, submitted my post twice. This one is removed.

[Lin Evans]

It does not matter if the on-camera lens is a large zoom or not.

Hi Shene,
I think you misread my statement. I said "large lens cameras" not large zoom. Large lens digicams do not do well with available 5x teleconverters, at least not any of the 20 or so large lens digicams I have which include the F707, S602Z, E10 etc.

The Eagle Eye OpticZoom 5x does really well with the smaller lens cameras in general, but not with "any" of the larger lens cameras which I've tested it with which include representative models from Minolta, Canon, Fuji, Sony, Epson, and Olympus.

Best regards,

Lin

[shene]

Lin,

Originally Posted by Lin Evans

I think you misread my statement. I said "large lens cameras" not large zoom. Large lens digicams do not do well with available 5x teleconverters, at least not any of the 20 or so large lens digicams I have which include the F707, S602Z, E10 etc.

In fact, "large zoom lens" here is exactly identical to "large lens" in your post. I used "zoom" because most consumer digicams have zoom lenses. I would use large-ratio zoom lenses for those lenses with a large zoom ratio (e.g., 5X, 8X, 10X, etc). The key, as was not made extremely clear in my previous post, is that no matter how large the prime lens is, as long as some optical characteristics (e.g., FOV of both lenses, the size of the exit pupil of the converter, the size of the entering pupil) match with each other, one can use that converter. When a zoom lens has very high zoom ratio, its FOV could be narrow enough to be contained in the exit pupil, even though the front glass of the prime lens is very large. In this case, only the center portion of the prime lens is used. So, whether the EagleEye can be used on a large lens actually depends on the exit pupil of the EagleEye and the FOV of the prime lens. Don't want to get into too technical. If you are interested, let us discuss off this forum. :lol:



CK
http://www.cs.mtu.edu/~shene/DigiCam
Nikon Coolpix 950/990/995/2500/4500 user guide

[Lin Evans]

Hi Shene,
Thank's, I understand optics. My point is that it won't work. There is no currently available digital camera with a large lens which will work without vignetting on currently available 5x or greater teleconverters, I'm not speaking from a theoretical perspective, we test them. I presently have 24 digicams with models representative of each major manufacturer's basic lens configuration which we test with currently available teleconverters. I have multiples of Eagle Eye OpticZoom 5x, CrystalVue 8x, Kenko 8x32, and a complete line of Nikon, Olympus, Kenko and a few off-brand tele converters which have cropped up over the years. Also we test a wide variety of spotting and astro-telescopes with available digital compacts as well as dSLR's. See the digiscoping forum here.

Best regards,

Lin

[shene]

Lin,

Originally Posted by Lin Evans

My point is that it won't work. There is no currently available digital camera with a large lens which will work without vignetting on currently available 5x or greater teleconverters.

Then, we are talking about the same thing. I provided a semi-theoretical explanation why converters may not work with some lens. Some calculation can be done to determine the level vignetting if technical data are available.

Originally Posted by Lin Evans

I presently have 24 digicams with models representative of each major manufacturer's basic lens configuration which we test with currently available teleconverters. I have multiples of Eagle Eye OpticZoom 5x, CrystalVue 8x, Kenko 8x32, and a complete line of Nikon, Olympus, Kenko and a few off-brand tele converters which have cropped up over the years.

It would be interesting to know your testing results. I also test some lenses; but, only serves my own purpose. Anyway, a higher zoom ratio and smaller gap between the the front and rear elements reduces vignetting significantly. A negative power rear elements will also alleviate vignetting. Let me show you an example. The following image is a Raynox MSN500 close-up lens mounted on Nikon's TC-E2. Both have negative rear elements. The large diameter of the TC-E2 (62mm) and the small size of the MSN-500 (37mm) may cause us to anticipate significant vignetting. In reality, there is virtually none!

http://www.cs.mtu.edu/~shene/FORUM/4...camera-1-s.jpg

Since these converters, the monoscopes included, are afocal systems, optical characteristics play a major role rather than the size of the prime lens. The following thread shows the results of using TC-E2 and TC-E3 with the MSN-500. None of them shows vignetting. Note that the zoom lens with the TC-E2 or TC-E3ED is quite large, in size.

http://forums.dpreview.com/forums/re...essage=5021937

Originally Posted by Lin Evans

See the digiscoping forum here.

Thank you for the pointer. I will go and look at it when I start digiscoping, perhaps soon, because a Zeiss Diascope 85T* will be ordered soon. I normally use my 35mm gear with 400mm or 500mm lenses. I may ask you questions over the digiscoping forum.

CK
http://www.cs.mtu.edu/~shene/DigiCam
Nikon Coolpix 950/990/995/2500/4500 user guide