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03-10-2011, 11:19 AM   #1
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Ways to get closer than 1:1

Well I have the stuff you can see in my signature.

What I can do right now is
- reverse the 50mm, going slightly beyond 1:1 - not enough
- stack the 105 Macro and the 50mm. Magnification maxes out at ~2.3:1.
- reverse the 50mm on my Vivitar 2x Macro TC
I'm not sure what I did exactly but with the 50mm on the TC reversed and with some extension I got around 3.3:1.
- reverse 50mm on the 105 macro which itself is on the macro TC. Could give me some additional magnification. Maybe 4:1.

But all of these possibilities have one thing in common: to much stacked glass. Loss of light and (I haven't tested the mega-combo) huge loss in IQ.

Then there is the Sigma 28mm lens. I don't have an adapter ring for it but I could just reverse this one also giving me slightly more than 3:1.
This seems to be the best way: it's simple to manage and the loss of light is as small as possible.
But field curvature is very strong so the focal plane is very shallow and magnification is fixed.

Therefore I have some questions considering the enlarger lenses and bellows option:
Do theses ELs have apertures just like "usual" lenses?
What is the flange distance?
How big is the image circle they cover?
What magnifications can be achieved?
How to mount them on bellows and the bellows on the camera? M42?
(RioRico? Hello?)

Future plus: could serve as tilt-shift lens.

What you should know:
I want as much working distance as possible and I guess the bellow-option would offer the most of these.
Also flexibility in magnification would be nice.
So say that I could go from 2:1 to 5:1 with just one lens set-up.

Spending as little as possible is the aim but results are more important than saving 50$ for me.
I don't use macro much and I don't even know what I should do with it but I know that I want to be able to do it...


Last edited by Egg Salad; 03-10-2011 at 11:50 AM.
03-10-2011, 01:50 PM - 1 Like   #2
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Easy+cheap ways to get past 1:1 include:

* That mount-reversed 50? Put some extension on it. Two cheap PK macro tube sets for US$8 each (shipped) should take you far. And a US$30 PK bellows will take you further. Working distance remains the same on the reversed lens.

* Cheapest+fastest reverse-stacking uses gaffers tape. Then you don't have to wait for an adapter ring to ship from China. You might find a cheap 200/3.5 to stack the 28 onto, that'll give over 7x magnification. But ANY magnification eats light. Argh.

* I have a couple macro TC's but don't use them much, mainly because they DO degrade IQ slightly. And I'm just used to the other techniques.

On EL's:

* Yes, they have aperture rings. If they don't, then they're projection or copy lenses, not EL's.

* EL's don't really have a "flange distance". They're constrained more by their focal length and the bellows thickness -- EL's longer than 80mm can reach infinity focus on the M42 and PK bellows I use.

* Image circle on those in the 35-75mm range will cover a 135/FF frame; those in the 70-160 range cover MF (645, 6x6, 6x9) easily; those of 150mm+ cover 4x5", etc. Yes, those are amenable to tilt-shift mounting.

* Magnification is strictly based on focal length and extension. A 35mm EL on 175mm extension is 4x. MAG = (TE-FL) / FL where TE is Total Extension. For longer lenses and/or more magnification, add some tubes.

* Many EL's are M39 screwmount. Some EL's and many bellows-macro lenses are M42. Many old USA-made EL's have weird mounts. I keep on hand a few cheap M39-M42 rings, and flanged M39-PK and M42-PK adapters. I also keep a batch of one-buck PK and two-buck M42 plastic body caps on hand, to dremel holes for those weird mounts.

* Side note: I use iris-less projector and Xray lenses on bellows and/or tubes. These often have NO usable mounts. So I sacrifice bits from cheap PK macro tubes -- contact-cement a ring to the lens' massive body, use such rings and a bayonet section to mount the lens on bellows or straight to camera. I did that just yesterday with a 1-kg Rodenstock XR-Heligon 120/1.8. Awesome! Heavy! DOF is molecular-thin!

Working distance and extension can be a problem. For any specific extension, you get more magnification with short lenses, but you also get a short WD. Longer lenses give greater WD but require much more extension for greater magnification. A 140mm EL on a 140mm bellows and another 140mm of tubes gives just 2x. Remember, your closest working distance will be the focal length of a non-reversed lens.

If flatfield sharpness isn't required, you could put a cheap manual 200/3.5 camera lens onto 200mm of bellows+tubes for 2x magnification at 8 inches working distance. Or you could put your 105mm macro onto 210mm of extension for 3x at 4 inches. That kind of trade-off just can't be avoided.

Hope this helps.

Last edited by RioRico; 03-10-2011 at 04:34 PM.
03-10-2011, 01:57 PM   #3
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I agree that the tubes would be the best alternative if you are concerned about stacked glasses. although this would mean that an off-shoe flash or macro flash would be necessary.
03-10-2011, 02:08 PM   #4
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When reversing lenses the magnification will be roughly focal length of back lens / focal length of front lens.

For example: A DA* 16-50 set at 16 reversed in front of an A* 300 would result in 300/16 = 18.75/1 magnification.

The problem with these setups is diffraction. With the aformentioned setup even with the 16-50 at it's maximum aperture of f/2.8 the aperture is only 5.7 mm wide at a focal length of 16mm. This results in an equivalent aperture of f/52 for the A* 300mm, not fun! (Great way to test for K-5 sensor stains though!)


Last edited by RXrenesis8; 03-11-2011 at 09:54 AM.
03-10-2011, 03:15 PM - 1 Like   #5
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lenses for 1-5x macros with bellows

QuoteOriginally posted by Egg Salad Quote
......

Therefore I have some questions considering the enlarger lenses and bellows option:

What magnifications can be achieved?
(RioRico? Hello?)

Future plus: could serve as tilt-shift lens.

What you should know:
I want as much working distance as possible and I guess the bellow-option would offer the most of these.
Also flexibility in magnification would be nice.
So say that I could go from 2:1 to 5:1 with just one lens set-up.

Spending as little as possible is the aim but results are more important than saving 50$ for me.
I don't use macro much and I don't even know what I should do with it but I know that I want to be able to do it...
Here's a couple important things to know about macro photography:
(1) Working distance increases with focal length at a particular magnification.
(2) Effective f-stop decreases with magnification for a particular focal length.

There is nothing you can do about these things; they are a result of physics. In equation form they are:
working.distance=focal.length(1+1/m) and f-stop.effective=f-stop.nominal(1+m)

If you obtain high magnification by stacking a close-up lens or reversing a lens on a primary lens you will have a brighter image than if you simply extended the original lens with rings or a bellows. But the working distance with the close-up lens will be smaller because what the close-up lens (or stacked reversed lens) actually does is to decrease the working distance. You can't win.

Bellows offer no fundamental advantage over extension tubes, but are easier to use to cover a range of magnifications. Typical M42 bellows will position a lens from about 30mm to about 150mm in front of the camera's lens mount. The relation between magnification and distance from the sensor is:

m= lens.sensor.distance/f -1 where for Pentax, the lens mount is already 45.5mm from the sensor.

When a 100mm Pentax lens focused at infinity is mounted on a Pentax camera, the effective position of the lens is 100mm from the sensor, so the distance from the effective lens to the rear of the lens is 100mm-45.5mm; in general a Pentax lens is f-45.5mm in front of its mount. Taking this into account,

m+1= (Pentax.lens.focal.length+extension)/Pentax.lens.focal.length

You say "So say that I could go from 2:1 to 5:1 with just one lens set-up."

Using a 28mm Pentax lens on a typical Pentax bellows (30-150mm extension) would give magnifications from about 1.0x to 5.3x, about the range you want. The working distance would be something like 56mm (at 1.0x) to 33mm (at 5.3x)

The answer is slightly different for a an enlarger lens on a bellows than for a normal lens on a bellows because the enlarger len's built-in offset is different. I measured the effective optical position of a 75mm enlarger lens from its mount and found it is about 13mm. When such a lens is put on a bellows, its magnification with a Pentax camera follows the formula:

m+1=(13.0mm + 45.5mm + bellows.extension)/f = (58.5+bellows.extension)/f

To get a magnification of 5x with a bellows extension of 150mm would require an enlarger lens of about 35mm.

If you want to get longer working distance than what these example indicate you'd need longer focal length lenses and proportionately longer bellows (or stacked tubes and bellows).

RE your other questions:
Do theses ELs have apertures just like "usual" lenses? Yes
What is the flange distance? I don't know if there's a standard, I measured 13mm from flange to the lens' effective position for a 75mm enlarger lens.
How big is the image circle they cover? This should not be a problem, they are probably limited by "natural vignetting" to a projection angular half-width of about 23 degrees
"How to mount them on bellows and the bellows on the camera? M42?" Most enlarger lenses have a 39mm thread, so I use an inexpensive 39mm to m42 adapter ring and an m42-K adapter at the camera.

If you are interested in tilt-shift for macros, there are a few bellows that will work. I have a Nikon PB-4, which can be found used for around $250 USD. For the Nikon bellows I use a 39mm-m42 adapter and an m42-PK adapter at the lens and a Nikon-PK adapter at the camera

Last edited by newarts; 03-11-2011 at 09:09 AM.
03-11-2011, 08:06 AM   #6
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Ufffff...
Lots of information. Will have to read throught this some more times I guess.

I knew I couldn't fight physics (would be an all time first) but I somehow thought with the bigger and longer ELs I'd gain working distance.
But I totally forgot about the light loss.

I have a macro ring flash and a Metz 48 but still a f/4 EL lens on 150mm extension is just dark.

Thanks all.
Need some time to think about this.
03-11-2011, 09:03 AM   #7
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Then there are the wild-ass options. For weird macros, put an ultrawide or fisheye lens on tubes. Not reversed -- that might be difficult. It means working very close, but oh, what DOF! Use such for shooting wee dead stuff in context.

At the other extreme... well, I have some strange lenses. One that just arrived a couple days ago is the Rodenstock XR-Heligon 120/1.8 xray lens (US$38 shipped) I mentioned above. It's nowhere near infinity focus, I'd probably need a NEX for that -- furthest I can get is about 50cm / 20in. But on even a bit of extension, it is still FAST, with correspondingly thin DOF. Just the thing for pinpoint-precision shots.

Another odd favorite, weighing about the same, is my brutally sharp Schneider Betavaron 50-125/4-5.6 fixed-focus enlarger zoom (US$70 shipped, marked down from US$3500). On 30mm extension it reaches infinity focus and is rather strange for non-macro use. On bellows+tubes it's extremely flexible, with a tremendous range of magnifications and working distances possible. This is about the only authentic "macro zoom" around. Ah, if only I had a 30-70mm focusing helicoid for it...

If you *really* want working distance, try something like this: a longish (300-400mm) telephoto on an nearly equal amount of extension, on a shoulder mount for stability. That's what I put on a half-frame film SLR (frame size about the same as a dSLR) to shoot close-ups of rattlesnakes on bright days from a safe distance, like around 3-4m.

For details on macro and other technical shooting, see the bible: Field Photography: Beginning and Advanced Techniques, by Alfred A Blaker, still an incredible bargain at Amazon (used). Don't leave home without it.
03-11-2011, 09:04 AM   #8
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I use M42 Asahi Pentax Auto bellows with enlarging lenses (el Nikkors, Fujinon, Schneider all M39). Works great and inexpensive. I have written this article on the inexpensive process.
https://sites.google.com/site/inexpensivemacrophotography/

03-11-2011, 09:17 AM   #9
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I have multiple ways of going past 1:1, all of which have the same basic common denominator, increasing lens extension,, and NOT by stacking any glass.

I do this either with extension tubes, and / or bellows or both.

For lenses, I use either SMC-M 100F4 macro, SMC-Macro-Takumar 50mmF4, or a 135mmF4.5 Schneider Kreuzanch Componar enlarging lens.

I can use either macro lens direct mounted to the camera for 1:2, I can go to about 1:.75 by adding extension tube sets between the lens and camera, and can go to 1:0.5 with the 135mm on the bellows, or about 1:0.2 by putting my 50mm takumar macro lens on the bellows and stacking extension tubes as well

Regardless of method, the level of magnification does require very intense illumination, and there is NOTHING that can resolve that point. High magnification spreads the image out substantially, and therefore the intensity goes way down.
03-12-2011, 04:59 PM   #10
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So...I should really have read about this again beforehand.

Further clarification: I said I want maximum working distance. This is still true but I found I'm comfortable with anything over 7cm(or 2 3/4in). I hope that makes it easier.
Also I don't need more than 5:1.

Regarding reversed lenses: I'm not sure anymore how working distance behaves.
With no extension (apart from flange distance), working distance for a 50mm lens is about 11cm/4,3in.
With 50something mm extension working distance is about 8cm/3.1in.
This is neither constant nor linear (or is it?).

I don't want to go with lens stacking because IQ degredation is pretty severe and light loss is even stronger than with other techniques.

I once tried to take that Vivitar TC apart but I couldn't find a way to remove the lens elements without destroying it. And this actually is a very neat thing so I didn't want to go so far (also it hurts the resale value).

RioRico, how is that Rodenstock XR-Heligon 120/1.8? Numbers are impressive.
1kg? That's a massive lens.

Seems like a 80mm lens would be perfect for working distance. But wow, 240mm extension for just 3x - or even worse 315 for the 105 macro. Damn you, physics!

For viewfinder brightness and necessary extension, I'd go with the 1.4/50. But the 105 macro should be better in whatever set-up.

RXrenesis8, luckily I don't own a DA* 300 so I don't have to worry about the effect of diffraction with the 16-50 stacked. Alos, 18,xx magnification might be just slighly over the top. Will be better off with a microscope then.

newarts, once again very valuable information.
You don't really motivate me but well, it's not your fault.
Looking at the numbers I can't find a combo that fulfills everything.
I either have to get very close or lose masses of light and end up with something like f/14 (4x with f/2.8 lens).
The bellows to EL or regular lens still is the most attractive to me. Primarily because of its flexibility and ease of use (focusing in particular).

Does someone know how much bellows with 2 geared rails usually cost?
Also, if I go the EL route which lenses I should look out for? Should be at least 75mm, cover more than 135mm film and offer f/4 if possible.

stover98074, I've read almost everything. Most ways to get close covered but I'm still not entirely sure whcih way I want to go.

Lowell, you have a strange way of naming magnification levels. It's clear but uncommon.

What did you mean by this?
QuoteQuote:
Regardless of method, the level of magnification does require very intense illumination, and there is NOTHING that can resolve that point. High magnification spreads the image out substantially, and therefore the intensity goes way down.
Resolve like resolution or disolving the problem?
Either you are talking about very tricky lighting or lost resolution because the image is so strongly magnified. Can you clear that up?


It's bellows against extension tubes with or without reversed lenses now.
Cheaper option: extension tubes + set of step-down rings.
More sophisticated option: bellows + enlarger lens or any other lens (even reversed).

Suggestions?

Last edited by Egg Salad; 03-12-2011 at 05:23 PM.
03-12-2011, 08:42 PM   #11
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Egg Salad -

When I want really a lot of magnification, I put an M 28mm f/3.5 reversed onto an SMC 80-200 f/4.5 lens. This lets you vary from 2.8:1 up to 7.1:1. At higher magnifications I had to use a flash. I think I posted some sample pictures in a thread, I'll see if I can find it.
03-12-2011, 09:53 PM   #12
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severe IQ degredation when using a lens stacking technique? Thats quite a broad statement that will potentially mislead many people. It depends entirely on the setup, and in some cases I have seen a jump in IQ (example is the F 135mm + reversed M 50mm. Its sharper this way than with the M 50mm and enough extension tubes to equal the same magnification.)
03-13-2011, 12:35 AM   #13
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Here's how close you can get to stuff with various setups:

1:1 - DA 35mm Limited


4:1 - Tamron 70-200 @200mm, reversed: DA* 16-50 @50mm


12.5:1 - Tamron 70-200 @200mm, reversed: DA* 16-50 @16mm


30:1 - A* 300mm, reversed: Sigma 10-20 @10mm


I would not call the degradation severe. In a properly exposed, focused, and stabilized shot it is no worse than simply shooting with an old, average lens. Which is to say: not as bad as some people think! The problem I've run into (as seen above) is that certain surfaces are not conducive to microscopy. The slick coating on the pack of gum I was shooting above acted like a layer of vaseline directly above the text, obscuring and blurring it.

Depth of field with a normal macro lens is a problem at 1:1. At 12:1 it's insane. I'd estimate the usable depth of field to be about 20-100um. Here you can see the problem:


And here you can see the solution:


Focus stacking, it's tasty!

As you can see, I've got one of those stained sensor thingies... I suppose I should send my K-5 back to Pentax if I'm going to be doing any more of this, I just... don't know what I'm going to do for a month while it's gone


Also: for reference, here is the setup:

Last edited by RXrenesis8; 03-13-2011 at 01:21 AM.
03-13-2011, 03:52 AM   #14
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QuoteOriginally posted by Egg Salad Quote
....................
Looking at the numbers I can't find a combo that fulfills everything............
I know the equations are hard to appreciate but they hold all the information you seek. I'll try to summarize them and what they say (basically they say meeting all your specifications isn't easy.)

QuoteQuote:
I found I'm comfortable with anything over 7cm(or 2 3/4in).....

Also I don't need more than 5:1..
Working.distance ~ focal.length(1+1/m), so for 70mm working distance, the focal length is calculated as follows:
70 ~ f(1+1/m) therefore f ~ 70/(1+1/5) = ~ 60mm or more

QuoteQuote:
Regarding reversed lenses: I'm not sure anymore how working distance behaves.
Stacking lenses reduces focal length therefore reduces working distance. The focal length equation is:

focal.length.stacked = f'f"/(f'+ff" - lens.spacing)

Say you stack a 50mm lens on a 50mm lens with 10mm between them; the new focal length is:
focal.length.stacked = 50*50/(50+50-10) = 28mm.

With a 28mm lens (ie. stacked 50's) at 5x the working distance would be:
Working.distance ~ 28(1+1/5) = 33.6mm

On the other hand, reversing (but not stacking) a shorter focal length camera lens on a bellows may be of interest to you. That's because a wide angle camera lens is designed so that when it is focused at infinity the rear of the lens is the flange distance away from the image plane. In the Pentax case, this is 45.46mm. This means even at infinite magnification the reversed lens' working distance is about 45mm.

The appropriate equation to describe this is:
Reversed.lens.working.distance= f(1+1/m) + flange.distance -f = f/m + flange.distance

A reversed Pentax type K 35mm lens at 5X would have a working distance of
35/5 + 45.5 = 52.5mm - not too bad!

At 2:1 the reversed 35mm working distance would be:
35/2+45 = 62.5mm - OK!

At 1:1
35+45.5 = 80 -good!

The reversed 35mm lens at 5:1 requires a bellows extension of about
actual.bellows.extension = f(1+m) -45.5 = 35*6 - 45.5 = 164.5mm - a normal bellows plus extension tubes.


QuoteQuote:
I either have to get very close or lose masses of light and end up with something like f/14 (4x [nb 5X] with f/2.8 lens).
Unfortunately getting close doesn't help. The effective f-stop is always the nominal times (1+m)*. Use a bright LED or halogen desk lamp to aid focusing.

QuoteQuote:
..............
Does someone know how much bellows with 2 geared rails usually cost?
You may be better off with a normal bellows and a 2 axis focusing rail setup (small sideways camera motion is difficult at 5x). The total cost for Chinese versions would be less than $150 USD.

If you chose a 75mm EL lens to maintain the working distance you want, you'll need about:
sensor.to.lens.distance = f(1+m) or
extension + camera.flange.distance = f(1+m) or
extension = 75(1+5) - 45.5 = 404.5mm - that's a lot!

You'll get maybe 150-180mm extension from a bellows so you'll need either many extension tubes or a shorter focal length lens and live with a smaller working distance.

QuoteQuote:
Also, if I go the EL route which lenses I should look out for? Should be at least 75mm, cover more than 135mm film and offer f/4 if possible.
There seems to be two basic quality classes for enlarger lenses, the best costs more, but the inexpensive isn't bad.

Dave

* when you stack lenses the effective f-stop (compared to the f-stop on the lens' barrel) decreases by a factor that exactly compensates for the increase in magnification due to the stacking. Increasing magnification by stacking doesn't decrease the brightness, rather it decreases the working distance. In that context your comment about "getting close" for brightness is correct.

Last edited by newarts; 03-14-2011 at 07:28 AM.
03-13-2011, 06:16 AM - 1 Like   #15
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The solution to your specifications!

Eureka!

QuoteOriginally posted by newarts Quote
I know the equations are hard to appreciate but they hold all the information you seek......

[i]On the other hand, reversing (but not stacking) a shorter focal length camera lens on a bellows may be of interest to you. That's because a wide angle camera lens is designed so that when it is focused at infinity the rear of the lens is the flange distance away from the image plane. In the Pentax case, this is 45.46mm. This means even at infinite magnification the reversed lens' working distance is about 45mm.

The appropriate equation to describe this is:
Reversed.lens.working.distance= f(1+1/m) + flange.distance -f = f/m + flange.distance...
A partial solution is to reverse mount a camera lens with a long flange registry distance!

Medium format lenses meet this criteria. Here's a short list from Lens Adapters - Photoethnography.com's Classic Camera DB

Lens type.........Registration, mm
Hasselblad .........74.90
Kiev 88 .............82.10
Pentax 6x7 .......84.95
Mamiya RZ ......105.00
Mamiya RB ......112.00

See Camera Mounts Sorted by Register for more.

For example, buy a $100USD Kiev 88 (Pentacon six) wide angle lens and reverse it on a bellows! It will meet your working distance and mag specs. Here's a 45mm example: Lens "Mir-26V" 3.5/45mm for KIev-88 TTL - eBay (item 160519719715 end time Mar-15-11 03:47:02 PDT)

The appropriate estimation equations for reversed camera lenses are:
Reversed.lens.working.distance = f/m + registration distance
Reversed.lens.extension.on.Pentax.K = f(1+m) - 45.5

working distance.Kiev88.45mm = 45/5 + 82 = 91mm
bellows.extension.Kiev88.45mm = 45(1+5) - 45.5 = 224.5mm

You won't find many shorter focal length medium format lenses that aren't fish-eye, so a compromise would be an Adaptall, T-mount, or Leitz Visoflex I lens:

Lens type................Registration, mm
Tamron T Mount ..........55.00
Tamron T2 Adaptall ......55.00
Leitz Visoflex I ..............65.50

For a $30USD reversed 28mm Tamron Tamron Adaptall 2 28mm f/2.5 Wide Angle Fast Lens Canon - eBay (item 230594399533 end time Mar-13-11 18:39:47 PDT)

working distance.Tamron.28 = 28/5 + 55 = 60.6mm
bellows.extension.Tamron.28 = 28(1+5) - 45.5 = 122.5mm

I think the Tamron Adaptall 28mm approach might come close to simply meeting your needs; a simple bellows would meet your 5x specification and it misses the working distance by only 10mm at 5X and only 3mm at 4X.

Another approach is to reverse mount a wide angle medium format lens onto a long primary lens to take advantage of the MF lens' long registration distance. My tests show that doing so changes the effective registration distance for the MF lens. My 65mm Kiev 88 (Pentacon Six) reverse mounted on a 300mm primary lens has a working distance around 62mm. Not too bad, but it demonstrates how stacking changed the MF lens' effective registration distance (in this case it decreased by at least 20mm)

Good luck!
Dave

PS. Sometimes hammering on a problem pays off!

Last edited by newarts; 03-14-2011 at 07:29 AM.
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