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Old Jun 23, 2004, 3:36 PM   #1
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and 3040mm (max shutter speed is 1/2000" but the camera has IS so maybe I could go to 5000mm possibly, and btw I have been able to handhold 380mm shots at 1/8" with IS on and 1/25" with IS off if I'm lucky, and more like 1/20" with IS and 1/60" without under fairly normal conditions) seems very attractive. Considering that, how long of a lens could I use and still have a reasonable chance to handhold shots at 1/800" to 1/2000" with IS on?

A couple concerns I have would be I'd prefer one that has a little vignetting as possible, and loses as little light as possible. I understand that I'm not going to get something perfect, for example I'm not going to have a vignetting-free F/8.0 picture at the camera's 38mm zoom, nor am I going to get an amount of light comparable to F/3.1 at the camera's 380mm tele, but as close as possible would be nice, without having to spend more than $200 or so. Also the ability to manually zoom the digiscope independently of the Canon S1's telephoto would be nice.

(from above) if lucky, able to handhold 1/8" at 380mm (35mm equivalent; actual is 58mm) with IS on. 1/2000 / 1/8 = a factor of 250. 250*380=95meter focal length, 250*58 = 14.5 meter actual focal length, which would make my lens 47 feet 7 inches long approximately, which would be much too long. I guess I could settle for an actual (in terms of the 1/2.7" (5.27x3.96mm) sensor) focal length of around 7 feet.

Also, I would like to be able to focus close enough so that at full zoom (and preferably also full wideangle) I can fill the frame with the pupil of someone's eye, with the iris being partially in the frame, and have it be sharp and in focus.

most of my gigazoom fast shutter shots will probably be taken either under daylight conditons, or of fairly bright objects. Also many of my superzoom shots might be at not quite kilometer-size-focal-length settings, with shutter speeds of "only" approximately 1/160" to 1/500" or so.

Any suggestions?
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Old Jun 24, 2004, 3:12 AM   #2
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Pianoman said; "...Any suggestions?"

You did not really explain what you wanted except that $200 was about what you wanted to spend, so I'd suggest the new Raynox DCR2020 2.2x teleconverter.

http://raynox.co.jp/english/dcr/dcr2020pro/index.htm


I should add that if you really want to try digiscoping simply take your camera and hold it up to theeyepiece of a binocular and see if it produces a good image. If it does you might take it with you to a store that sells telescopes and try it again. If not you may be better off to buy a different camera rather than needing to buy an expensive lensed adapter such asthose sold by Scopetronix.com.
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Old Jun 24, 2004, 6:55 PM   #3
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I'd like an optical reach of at least 2000mm if possible, so a 2.2x teleconverter won't cut it. That would only get me somewhere around 836mm. I am fairly good at holding the camera steady at 380mm with IS on - I was able to get shutter speeds down around 1/10" to 1/20". Most of the shots I will probably take would be around 1/500" to 1/1000" in daylight settings at F/3.1 and I'd like a zoom that will go out quite far.
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Old Jun 25, 2004, 9:16 PM   #4
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2.2x isn't enough magnification for me. I will be taking telephoto shots from a much farther distance, and would like a maximum telephoto focal length of at least 2000 to 3000mm. Considering I have been able to handhold 380mm shots at around 1/20 sec, I should probably be able to handhold shots at around 1/200" to 1/320" with IS on with the Crystalvue 8x scope. (8x * 380mm = 3040mm)
What do you know about that scope, or is there something better for a comparable price that has at least the same magnification, and preferably less vignetting at wideangle?
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Old Jun 25, 2004, 9:51 PM   #5
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I think 2.2x is about all you are going to be able to add to the S1 IS. Lenses such as the Crystalvue just don't work well with 10x cameras. Ask the Crystalvue salesman and that is what he will tell you.
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Old Jun 26, 2004, 12:09 AM   #6
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Pooperdog wrote:
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I think 2.2x is about all you are going to be able to add to the S1 IS. Lenses such as the Crystalvue just don't work well with 10x cameras. Ask the Crystalvue salesman and that is what he will tell you.
I don't think 2.2x is going to cut it. At the bare minimum I'd like something to equal the camera's digital zoom, which would be 1216mm or 3.2x, not 836mm or 2.2x. A longer ratio, like around 2000mm to 3000mm, would be nice. I can handhold fairly slow shutter speeds, so I would think up to 2 meters or 3 meter focal length would be ok for handholding daylit shots.
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Old Jun 26, 2004, 8:31 AM   #7
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Basically $200 isn't going to buy youmuch. Go to http://www.scopetronix.com/and just look at the price of the S1 IS cameraadapters.


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Old Jun 26, 2004, 3:52 PM   #8
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I might be willing to go up in price some, but I would still prefer that the combination of the price of the lens and the 4GB microdrive I recently got (which works fine btw) would still be less than the cost of the camera.

At the bare minimum I would like a teleconverter that will have the equivalent power of my digital zoom (3.2x).
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Old Jun 26, 2004, 4:11 PM   #9
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Well there is a guy who uses the Crystalvue with an Oly C7xx but he has to tolerate some significant vignetting. Maybe he has done some more testing by now. See;

http://www.timotk.net/crystalvuetest.htm

If you are willing to ignore those black circles you could try it. That is about your only option above 2.2x without an adapter or a different camera. Of course there are other things you could also try that would also give you the same black circles;

http://www.jayandwanda.com/coolpix/captain/captain.html


Let me add that digiscoping is mostly limited to a few known cameras and others that are tested by individuals and found to be adequate. The basic features of a desirable camera are a small diameter lens and a non-moving lens. The favorites are the old Coolpix models that have 28mm diameter lenses. Other cameras with larger lenses can be used if you buy the rather expensive adapters such as those sold by http://www.scopetronix.com.

The favorite cameras and the basic technique is described here;

http://digiscopingukbirds.homestead....opingInfo.html


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Old Jun 26, 2004, 10:32 PM   #10
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I did a few tests on my S1 with a pair of 7x50 binoculars.

all pics are unedited, straight from camera, shot at exposure compensation -2, in aperture priority (F/2.8 or F/3.1 if I remember correctly), and various ISOs ranging from 100 to 400.

camera - wideangle

camera - full optical zoom

camera - digital zoom


camera with binoculars - wideangle
(I would like somewhat less vignetting at wideangle than this - more like what I have at full zoom would probably be acceptable)

camera with binoculars - full optical zoom
(btw I was temped to do a "levels" command on this but figured it'd be easier to analyze performance if all shots were unedited, also, I'd prefer much less if not no vignetting at telephoto. I should mention that the binocular eyepiece is somewhat smaller than the end of the S1 lens.)

(camera with binoculars & digital zoom - not shot)

Although the binocular shots are probably the absolute WORST super-tele shots you have EVER seen, that's actually a decent representation of the amount of preferably good quality magnification I'd like to get. (although a little bit more would be nice.)

btw, all the shots were handheld, in near-daylight. The sun had recently gone behind the hills to the west, but there was still quite a bit of light to see by.

As far as full zoom vignetting goes, I don't mind if the corners are cut off or a little dark, but I'd prefer not to have the top, bottom, left, or right cut off.

a few resized examples (taken from my full-optical telephoto no-binocular shot):

unacceptable at telephoto, still more than desirable at wideangle:


I could probably use this at telephoto for a few shots, at wideangle this would probably be quite OK


Telephoto with this would be quite acceptable under most circumstances, and if I could get this at wideangle it'd be really nice.


there isn't really much of a difference between the last 2. It's just that only the top & bottom are not cut off on the first one, whereas the second one all 4 sides are visible)

At full telephoto, this much vignetting would be REALLY nice to have. I don't think there is ANY lens that will get this at wideangle, right?
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