microphotography of coins

I want to take micro-photographs of coins. Currently I'm using a Canon 5D, EF

100mm F2.8 Macro USM lens, and MR-14EX Macro Ring Light to get up to 1x

magnification. This is working great. But, I need to supplement this with

higher magnifications.

 

I'll need magnifications from about 4x to 40x. I assume the best setup for this

will be a microscope with three or four objective lenses. Aside from this

assumption I only have questions:

 

Are there any good resources (books, web sites, ...) to help me understand the

issues I should expect to face?

 

Can I expect a microscope's optics to give me a full image without vignetting?

 

How should I light a coin on a microscope?

 

Are there other good options?

 

So far this is the best microphotography related site I've found:

http://www.its.caltech.edu/~atomic/snowcrystals/photo2/photo2.htm.

 

Thanks,

Tim

Coins are not entirely flat, so you may actually run into depth of field options.

 

If you haven't tried it, check into the macro coupling ring approach. Don't know that it will get the job done, but it's a cheap approach.

 

If your end result does not require extreme image quality, consider cropping a fairly small part out of the frame IE, "digital zoom". That should take you from 1X to 4X or 5X and still have a reasonable image for most purposes.

I don't want to type what I've already typed more than once. Use the forum search feature!

 

Also look go to filmlives dot net (photo dot net) blocks references to it and look at their resources for macro photography article. I wrote it.

 

I'm not sure I've typed it anywhere, so be aware that below around 20x a compound microscope is worse for many reasons than a proper photomacrography setup.

 

Canon user, eh? Canon makes a nice macro lens in EOS mount for 1x-5x. I'm surprised that you're not aware of it.

Due to the depth of field problem, I have been happier with shots made with an old Leitz enlarging lens on an M42 bellows than with those using the microscope.

Like Doug says. Get yourself a high quality 6-element enlarging lens, preferably a short one for a very small format. 28-35mm is nice. Rig up an adapter to *reverse* mount it on a bellows or extension tubes. Unfortunately the front of every enlarging lens ever made seems to be a different size, thus I ended up making several different adapters for several different lenses. It's the old 25mm Schneider I use the most for tiny details.

Tim, this is what you're looking for.

 

http://www.usa.canon.com/consumer/controller?act=ModelDetailAct&fcategoryid=155&modelid=7325

I believe a bellows gives you about 25x, maybe more with extension tubes, and depending on the lens you use.

Here's a review of the same lens linked above:

 

http://www.the-digital-picture.com/Reviews/Canon-MP-E-65mm-1-5x-Macro-Lens-Review.aspx

40X for coin? At this magnification, only one surface of the coin (e.g.: base or the top surface of the engraving) is within the DOF. 1:1 to 3:1 may be easier to work with.

 

For a book on macro photography check out The Manual of Close-Up Photography, Lefkowitz. A good web site for microscope info is

 

http://www.microscopy-uk.org.uk/full_menu.html

 

Yes, a microscope objective like a Ziess 10X 160/- planer can yield a full image on a full frame 35mm without significant vignetting (at 116mm extension).

 

Here is a sample snap shoot of 100% pixel crop of a dime. The image is the lower left of "D" above the year 2005. Notice, only the surface of the D is in focus. Excuse the poor lighting.

OOps, Here is the snap shot.<div></div>