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Digiscope to objectively compare binos?

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shaocaholica View Drop Down
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    Posted: July/22/2009 at 17:56
Would using a very controlled digiscope setup be acceptable for comparing binos objectively?  Are there any impartial places that do this already?

All you'd need is a decent DSLR with a lens that has good to excellent distortion control, sharpness and CA control so as to not pollute the results.  Although I'm not sure exactly how the 2 different optical systems will interact with each other which may produce some unwanted results that otherwise would not be an issue.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote koshkin Quote  Post ReplyReply Direct Link To This Post Posted: July/23/2009 at 18:17
What exactly are you trying to compare?  What metrics do you plan to use?

ILya
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Post Options Post Options   Thanks (0) Thanks(0)   Quote shaocaholica Quote  Post ReplyReply Direct Link To This Post Posted: July/23/2009 at 18:20
Sharpness, CA, distortion.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote koshkin Quote  Post ReplyReply Direct Link To This Post Posted: July/23/2009 at 18:31
You can do that, but you would be better off getting a camera without a lens, where the imager can be placed where the eye would be otherwise.

I've done that kind of analysis at work, and, while very interesting, it is ultimately not very practical unless you do this full time.

ILya
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Post Options Post Options   Thanks (0) Thanks(0)   Quote shaocaholica Quote  Post ReplyReply Direct Link To This Post Posted: July/25/2009 at 22:44
Originally posted by koshkin koshkin wrote:

While very interesting, it is ultimately not very practical unless you do this full time.
So I guess there are no places that review binos objectively periodically?  I guess the market isn't that big.  I wouldn't mind trying it but it seems tricky technically.  Seems like you can't just have a sensor where the eye goes because the eye is not just a sensor but also a lens.  So you'd also want to use a lens perhaps, one thats similar to what the eye is doing when looking through binos and also robust enough not to introduce any artifacts that would mar the results.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Duce Quote  Post ReplyReply Direct Link To This Post Posted: July/26/2009 at 13:19
I would think you would need a very high resolution camera to get meaningful results, something like the Hassenblad 60 mb digital photos. Cost could be a consideration  the camera is over 30 K not including the adapter and lens.
 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote shaocaholica Quote  Post ReplyReply Direct Link To This Post Posted: July/26/2009 at 13:58
Originally posted by Duce Duce wrote:

I would think you would need a very high resolution camera to get meaningful results, something like the Hassenblad 60 mb digital photos. Cost could be a consideration  the camera is over 30 K not including the adapter and lens.
 
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Those hassies are medium format cameras so the actual density of the sensor isn't really that high.  Theres no way binos made for human eyes would be able to fill the entire medium format sensor.  We I'd need is something to simulate the human eye.  I would be surprised if current top end binos could out resolve a current moderately priced APS-C DSLR.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote koshkin Quote  Post ReplyReply Direct Link To This Post Posted: July/26/2009 at 17:54
I have used sensors with 2.0, 2.7, 4.25 and 5.0 micron pitch to look at images through riflescopes and binoculars.  You can see a touch more detail with top end models with the smallest pixels, but not by much.  Ultimately, 2.7 micron pixels gave me the best combination of dunamic range and resolution for higher end optics.

Most modern day DSLR sensors have pixel pitch between 4.25 and 7 micron, so that would work pretty well.

As far as replicating the lens that is in the eye goes, good luck with that.  We are quite a few years away from being anywhere near that.  Besides, the wonder of human vision is not in the lens.  The lens itself is interesting due to its adaptabbility, but that is it.  We see the way we see because our bran provides absoultely unrivalled (for now) DSP.

ILya
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Post Options Post Options   Thanks (0) Thanks(0)   Quote shaocaholica Quote  Post ReplyReply Direct Link To This Post Posted: July/26/2009 at 22:27
Koshin, when you talk about ~3 micron photosites, are you talking about a compact camera?  Did you take the pictures with the lens removed or still attached?  I suppose a mirrorless compact would work well since you can get the sensor to within the eye relief distance.  Perhaps the new micro four thirds mirror less cameras will allow the same thing with a bit more control than a gutted point and shoot but thats a bit beyond what I was planning on.  I just wanted to see if I could re purpose my DSLRs.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote koshkin Quote  Post ReplyReply Direct Link To This Post Posted: July/27/2009 at 00:17
Originally posted by shaocaholica shaocaholica wrote:

Koshin, when you talk about ~3 micron photosites, are you talking about a compact camera?  Did you take the pictures with the lens removed or still attached?  I suppose a mirrorless compact would work well since you can get the sensor to within the eye relief distance.  Perhaps the new micro four thirds mirror less cameras will allow the same thing with a bit more control than a gutted point and shoot but thats a bit beyond what I was planning on.  I just wanted to see if I could re purpose my DSLRs.

I work for a company that makes CMOS imagers for high end photography and digital cinema applications, so I have access to bare sensors.

Trying to do it with a commercially available point-and-shoot or DSLR camera is a bit difficult since you do not have access to raw output from the sensor.  Also, even if you keep the mirror up, there is still AA filter and IR filter in front of the sensor which mess with the resolution and contrast a fair bit.  Basically, you so not know how much fltering has been done to the original image by the imaging pipeline while reconstructing the colors, sharpening, etc.

Additionally, if you are tyring to compare a couple of binoculars you need to have access to studio conditions where you can set up consistent lighting and scene sufficiently far from the binocular for the focus to work properly.

ILya
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Post Options Post Options   Thanks (0) Thanks(0)   Quote shaocaholica Quote  Post ReplyReply Direct Link To This Post Posted: July/27/2009 at 01:21
Originally posted by koshkin koshkin wrote:

 I work for a company that makes CMOS imagers for high end photography and digital cinema applications, so I have access to bare sensors.

Haha, you work for the mystery company that supplies RED?Cool

Yeah, the AA filter can get in the way but its not a show stopper.  There are plenty of SLR lens reviews done on commercial equipment and it works out pretty well.  Quite a few compacts and all DSLRs can give you raw sensor output, maybe with a little processing, but for the most part negligible for my purposes.  I'm going to try it with a micro four thirds cam (which can output raw) and see what happens.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote koshkin Quote  Post ReplyReply Direct Link To This Post Posted: July/27/2009 at 12:12
Originally posted by shaocaholica shaocaholica wrote:

Originally posted by koshkin koshkin wrote:

 I work for a company that makes CMOS imagers for high end photography and digital cinema applications, so I have access to bare sensors.

Haha, you work for the mystery company that supplies RED?Cool

Yeah, the AA filter can get in the way but its not a show stopper.  There are plenty of SLR lens reviews done on commercial equipment and it works out pretty well.  Quite a few compacts and all DSLRs can give you raw sensor output, maybe with a little processing, but for the most part negligible for my purposes.  I'm going to try it with a micro four thirds cam (which can output raw) and see what happens.

There is no particular mystery about who supplies RED, and I do not work for them.

As for SLR lens reviews, the lenses are designed to work on a camera body, so that is how they are reviewed.  With scopes and binoculars it is a bit different, but give it a shot and see how it works for you.

ILya
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Post Options Post Options   Thanks (0) Thanks(0)   Quote shaocaholica Quote  Post ReplyReply Direct Link To This Post Posted: July/27/2009 at 12:56
Considering how theres no consumer analog for a human eye, I have to go with the next best thing.
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