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Canon DSLR Challenge | all galleries >> Challenge 77: Single Light Source (Host: Michael Puff) >> Challenge 77: Eligible > Hobo Baby
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24-SEP-2006 Jim H.

Hobo Baby

A few baby hobo spiders decided to descend on their silk from a lamp on my desk. The nearest thing I had to catch them on was a CDR. The light from a single flash head caused the colors in this due to the diffraction of the light by the "groove" in the CD. Although the tiny spider appears to be suspended in air, it's actually resting on the front face of the CD. The space you see is the thickness of the CD separating the spider from the back (data) side of the disc. The spider was quite tiny as this is a full-frame at 4 to 5X. At this stage, these spiders are fairly translucent. They appeared to be white when viewed by the naked eye.

Canon EOS 20D ,Canon MP-E65mm f/2.8 1-5X Macro
1/250s f/13.0 at 65.0mm iso200 full exif

other sizes: small medium original auto
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Guest 03-Oct-2006 18:34
Great idea and execution. The rainbow of colors is wonderful. -Michael
Eric Delmar29-Sep-2006 00:18
Jim,
First off, exceptional (and voted) image. I enjoyed reading about this lens. As a Nikon shooter and macro enthusiast, I continue to be frustrated by Nikon not having anything optically similar. That said, I'm glad there are people such as yourself that explore these wonderful optics and have a blast with them. Enjoy, Eric
Canon DSLR Challenge26-Sep-2006 15:30
Great spider pic, really sharp - the details are amazing, and the colors are terrific. The spider looks as if he's floating in air - rather surreal. Are they poisonous? CJ
Michael Kilpatrick26-Sep-2006 09:55
If a spider can look cute........ this one almost does. This is a stunning image - I love the sharpness of the spider and the colour combination.
jnconradie25-Sep-2006 15:22
Thanks for the detailed explanation of the lens and how you work with it, Jim. I appreciate the information very much. And of course the photograph is stunning - as per always! Regards ~jnconradie
Guest 25-Sep-2006 14:21
WOW awesomeeeeeeeeeeeee!
Cherylm
Canon DSLR Challenge25-Sep-2006 13:20
Fabulous, creative and creepy! As far as I understand it (still fairly new to this), the diffraction limits are theortical calculations based on perfect optics/construction, I'm not sure they should be taken too literally with regular photo lenses. -Najinsky
Canon DSLR Challenge25-Sep-2006 12:30
Thanks!

Forgive me for this longish post. I thought about posting this in the challenge thread, but then I figured that people could just skip over this if they’re not interested in the lens. So skip this if you’re not interested in my thoughts about this lens :)

I just love this lens. I think it's always a bit of a challenge to use, but not so much in focusing as in finding the target in some cases.

To me, this lens is just like having a macro lens on a set of bellows. You don't really focus it so much as you just dial in the magnification that you want and then move the camera/lens until you've got the subject focused where you want. When you turn the adjustment ring, you're actually extending the length of the tube so you cannot really just focus on something in a conventional way.

But in a way, this is a lot like the way I'd use a "regular" macro lens at higher magnifications. I sort of set the focus (which sets how far you can be from the subject) and then move back and forth a bit until the image seems to be focused where I want. It's the back and forth movement that achieves the final focus for me with any macro setup (at higher magnifications).

I almost never use this lens on a tripod. Then again, I almost never use a tripod at all. But I almost always use flash or a very high shutter speed for macros so that my movements will be frozen. In a way, I just try to time the shutter press to match the point in time when the subject happens to be in focus. It's almost like shooting sports, I guess, except that I'm trying to capture the moment when focus is right :)

But I also cheat all that I can. For this shot, getting focus was easy because the spider sat still for fairly long periods and I had the CD sitting on the keyboard of a computer (right where he was lowering himself on his silk). That put it up at just the right height that I could hold the front of the lens in my left hand and rest that hand on the desk. So then I was able to make small movements of that hand to adjust the position of the front of the lens. And that's how I have to frame things and get the focus. It's those small movements that do it.

And perhaps, it’s because I don’t use a tripod that I find this lens to be easier to use than some people. I think that on a tripod, you’d have a darn hard time acquiring focus because you’d have to move the tripod back and forth in movements far too small to achieve easily. I think some folks use focusing rails with this lens. I think that would be a necessity for tripod shooting with this, or any other high-magnification shooting. I just don’t see how else you’d get things in focus.

But I also think that for most things, you’d run into the same problems that always bother me with a tripod. By the time you get everything set up for that one shot, the subject has moved or you realize that you want things just a bit different. Hand-held, you can just move as you see fit. So I guess you trade ease of focus and ease of framing and subject tracking for the ease of steady-holding that a tripod would bring.

The hardest part at higher magnifications for me, is to find the little critter in the image. I often find myself searching with a sort of "nutating scan", kind of like a raster pattern if you will. Then, I'll give up and take my eye away from the finder and look at the scene to try to determine the position of the front of the lens with respect to the subject, and then go back to the search. Once I've got the target in view, then I can move to get it in focus.

I have that odd "lens hood" for this lens, and I recommend it highly. If nothing else, it provides a smaller "pointer" showing better where the lens is aimed :) It's an odd thing for a lens hood. It screws into the filter threads and has a smaller opening in it than the front of the lens. I feel that it offers great protection for the lens and serves the purpose of making the front of the lens smaller so that I can better judge where it’s aimed.

The DOF is always tiny with this lens, but then so is the area you’re observing. So I guess it’s just proportional to the magnification, really.

One thing that amazes me is that the lens seems to remain sharp even at small effective apertures. I’ve seen some diffraction calculators on line and it seems that f/13 is about as small as you want to go for a 20D. Going much smaller tends to soften the images a bit as diffraction becomes more dominant.

But this lens, due to the “built-in-extension tubes” effect, has very tiny effective apertures.

At 1X, the “effective aperture” range is f/5.6 to f/32. At 5X, it’s f/16.8 to f/96.

Effectively, at 5X, and a lens setting of f/13, you’re really at f/78! Yet shots taken at that setting don’t seem to be as horrible for diffraction as one might expect. So I think something else is going on inside the lens that mitigates this.

But I can tell you that the sensor dust you see IS proportional to that effective aperture. No matter how well you’ve cleaned your sensor, you WILL see sensor dust on your MP-E shots at these tiny effective apertures.

And this “effective aperture” business brings up another issue. The aperture rating of the lens is f/2.8. Yet even at 1X, at f/2.8, the effective aperture is f/5.6 – and at 5X, it’s f/16.8. This has to do with the way they have to rate apertures. They’re always rated at infinity focus. And this lens cannot focus at infinity. But if it could, then it would supposedly be an f/2.8 lens.

So the problem is that when you’re looking through the lens at 1X, it’s as dark as an f/5.6 lens. And at 5X, you’re viewing at f/16.8. So you need very bright light to just see for focusing and framing. I often use a small LED flashlight aimed right at the subject. Or if I’m using the MT-24EX flash, it has some little “headlights” that you can turn on to aid in viewing. They’re a must!

I hope that's helpful and not too boring for everyone. Thanks again. Jim H.
Vikas Malhotra25-Sep-2006 11:14
WOW thats a beauty Jim. Love the colours in the background. Regarding the MP E65 lens, how do you find it for practical use? Is it really difficult to use/focus with the enhanced magnification? I am tempted to buy it but worry about the DOF/focus issues. As it is, I find focussing with 67mm of extension tubes on my 100mm macro a huge strain. :-) Dont know anyone here who has it else would have tried it out and will have to specially order it with my lens supplier.

Cheers, Vikas.