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Old Oct 21, 2002, 5:53 PM   #1
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Default Digiscoping with Kowa TSN-823 & Dimage 7Hi

I'm interested in Digiscoping, I have a 82mm Kowa TSN-823 with a 20x60 zoom eyepiece. I'm think of buying the new Minolta DiMAGE 7Hi to adapt to my scope. The Kowa people tell me I need a (1) TSN DA1 Digital Camera Adapter, (2) TSN-DA1-ARZ7 Zoom Extension Ring, and (3) a Adapter Ring to fit the 49mm Minolta Lens, be it a Step-up to 52mm or a Step-down to their 43mm.

I have no previous experience in Digiscoping and could sure use some help and advise as to wheather anyone is currently using this set-up, or any general advise about using the 7Hi for Digiscoping. I also need information about a extend-a-shade for 7hi LCD.

Thanks :roll:
A new member,

Gary Aspenall
San Jose, CA.
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Old Oct 23, 2002, 6:14 AM   #2
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The Minolta may be a very unwise buy as far as digiscoping goes... (from looking at the specs rather than any first hand experience), sure someone will be happy to sell you an adapter to fit the two together....but they won't be promising any results.
Nikon cp990/995/4500 are the cameras that will produce good results, a few other cameras can produce good results.... those with large diameter lenses and powerful built-in zooms (often one and the same) usually result in frustration for digiscoping.
Regards,
Andy B
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Old Oct 23, 2002, 5:56 PM   #3
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Default Kwoa & D7Hi

Thanks Andy B for your quick response and opinion.

I'm hoping this was'nt a mistake, As of today, I now own the Minolta 7Hi and are awaiting the ordered adapters from Kowa, I know I'm going to have some vignetting problems with a 52mm step-up but hope to be able to edit or crop out the black on the computer. I guess I'm in for a dime in for dollar at this point. However I will be reporting on my success or problems for others to learn from.

Thanks again,

Gary Aspenall
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Old Oct 24, 2002, 1:56 AM   #4
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Good luck, Gary. Hope it works out with the Minolta (damn good camera), be nice to recommend a non-Nikon for digiscoping..... and you're right about cropping away the vignetting being easier with cameras with a big pixel count (and for web/monitor pics especially).
Andy B
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Old Oct 24, 2002, 12:45 PM   #5
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Hi Gary,

I agree with Andy that the Minolta probably won't be a great digiscoping tool, primarily because of extreme vignetting and greatly reduced range of zoom, but it is a great digicam and offers many other superior features.

My suggestion would be to try it, but if it doesn't appear to do what you like - consider getting a second digicam for digiscoping purposes. There are two primary uses for digiscoping: wildlife, including birding - and astronomy. The Minolta may prove to be an excellent camera for photographing the moon and some planets, especially if used in conjunction with "stacking" software which reduces noise and increases relative signal. But, for birding or wildlife use the lack of zoom range would likely be an issue.

You might consider looking for a used CP990, or even a CP950 - either of which makes a great digiscoping camera. Rather than spend too much trying to "fit a square peg in a round hole" it might be better to concentrate on getting a second camera for the digiscoping tasks.

Best regards,

Lin
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Old Oct 24, 2002, 1:44 PM   #6
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Default 7Hi Digiscoping

Thanks Andy & Lin for your responses,

Lin, could you please tell me more or what to expect about the lack of zoom range you mentioned or why it would be an issue?. I'm mostly interested in Digiscoping as it pretains to Birding. Will I always be using the wide angle setting or 28mm setting on the camera?, also will I be using Auto Focus or Manual Focus?. I also picked up an 18" remote shutter release button. Do you first focus your scope than mount your camera and then attempt to use Auto Focus if the bird is still there?. I know these sound like dump questions, but it's like being on the edge of space and there's such a huge-huge new world of digiscoping out there to discover. The Camera people can tell you anything and the Spotting Scope people can tell you anything.

Thanks again,

Gary Aspenall
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Old Oct 24, 2002, 2:42 PM   #7
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Hi Gary,

In all probability, you will always be using the full telephoto function of the camera, and even then will likely have significant vignetting.

The reason zoom is an issue for birding is simply that depending on the type eyepiece on the telescope and degree of vignetting on the camera, it's usually necessary to zoom back from full telephoto in order to frame the entire bird. With a camera like the Nikon CP series (CP950, 990, 995, 4500, etc.) you have a relatively tiny lens which, with one or more wide angle eyepieces, will let you zoom nearly the entire range of up to 4x without vignetting. The wider the angle of view (less telephoto) the greater the propensity for vignetting. With many of the larger lens cameras, at full wide angle you would only have a tiny "tunnel" of visible image to work with. To get even a usable image you often need to zoom in to full telephoto.

The procedure used with the Nikon CP series is a little different than what you would use with the Minolta because the Nikons don't have an EVF (electronic viewfinder). Because the telescope totally blocks the optical viewfinder and in no way is representative of what the camera is "seeing" when attached to a telescope, Nikon users use a combination sunshade/loupe which allows them to use the LCD as a viewfinder.

With the Minolta, you can simply use the EVF because it's actually looking through the lens of the camera, and thus through the telescope as well.

First adjust the telescope's focus for the best possible image, then with the camera set for focus at half shutter press, depress the shutter half way and let the autofocus lock. Finally, if necessary, touch up the telescope's fine focus and shoot. This is the procedure I use, but you will want to experiment to get the best combination for your individual equipment.

When at all possible, shoot with a reasonably small aperture to get best depth of field. This will depend on lighting conditions, but even with a prosumer camera like the Minolta, which normally has much greater depth of field than a 35mm film equivalent, depth of field will be greatly shortened when using a high power telescope as a lens. Sometimes the conditions are such that this isn't possible, and at these times, the ability to zoom back from full telephoto lets you increase available light and increase depth of field.

I don't want to sound discouraging about using the Minolta for digiscoping, but the probabilities of doing it well with a larger lens camera with greater zoom on the lens is minimal. That's why I think you might want to consider the possibility of getting a second camera if digiscoping is going to be a large part of what you do photographically.

Best regards,

Lin
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Old Oct 24, 2002, 3:19 PM   #8
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Default 7Hi for Digiscoping

Lin, Thanks for the information and advise,

I'll keep you posted as to any successful results or if I can pickup a used CP4500 just for Digiscoping. Too bad I was trying to love two birds with one camera. Sounds like I'll just have to own two Digicam's.

Thanks

Gary Aspenall :
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