Featured A new piece of kit for coin photography....

I snipped the parts that weren't really addressing my concern.

I appreciate your response, and have the following concerns:

For coin photography, don't you *want* to shoot manual focus, anyway? Copystand + cheap Nikon dSLR + 105 microNikkor = $280 give or take. Yes, you can't shoot full slabs without changing a lens, but the 18-55 kit lens seems viable for that purpose.

The 105 gives enough working distance that axial lighting isn't really necessary (unlike the 50mm microNikkor, which you can get in manual for as low as $5).

Now this is a sincere question, as I've shot large format sports photography before (not the best idea, but you capture a lot of the action when shooting at infinity): How does a bellows not impede light when they're approximately the same diameter as the lense, but even longer (when increasing magnification)?

BTW, for those who have problems shooting manual with a digi fixed setup, I've found that using the camera's digital zoom helps with this. You zoom in as far as you can digitally, and focus *that* image. It works similarly (in concept) to focusing with a prism.

 

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The bellows does not impede the light, because it's not in the way of the light. The only relevant light is that proceeding directly from lens to sensor. The bellows is significantly larger than the lens glass in our application, in the case of my Componon-S (and most duplicating lenses), double the size.

What does impede the light is the fact that magnification affects aperture in a mathematical relationship, the greater the magnification the tighter (higher numerically) the "effective" aperture. You didn't run into that in sports photography. Further, 1:2 magnification gets you a Morgan filling the sensor, but nothing smaller, and the goal is to fill the sensor with the coin. So you need yet more magnification, meaning yet tighter apertures and quicker onset of diffraction.

Diffraction is the enemy, and magnification hastens the onset of diffraction. We're working at a resolution scale where any diffraction creates a noticeable degradation in quality. That's the specific reason I'm working with a 10MP sensor rather than higher - diffraction is also a function of pixel pitch and the larger pixels of a 10MP sensor allow me an extra stop or so that I can then burn in increased magnification before the onset of diffraction.

Digital zoom is not relevant to macro photography. If you want to zoom your image digitally, do it with far more sophisticated software and far more powerful hardware on your PC, not in the camera. By this method, you're manually focusing on your monitor anyway, and ought to be able to see if it's in focus or not. Digital zoom in-camera pretty much abandons any pretense of sharpness as it forces the camera to add pixels to fill the same space as the sensor does natively.

So your 105 will require a bellows or spacers to increase the magnification to something acceptable, plus the assumption that the lens will remain sharp at a magnification it wasn't designed for since, out of the box, it's unsuitable for anything smaller than a Dollar and - it should be mentioned - requires a working distance beyond the capability of many stands. Assuming it is OK at higher mags, and you have the ability to place it a sufficient distance from the subject, then the 105 is a possibility as one of the lenses for use with this system.

I am going to have to modify my technique rather heavily to evaluate the 150mm El Nikkor I just acquired. My stand - which has enough extension to employ a dSLR with a Canon 100mm Macro, I've done it - will not come close to the extension I need for 150mm.

 

Not only do you not need a macro lens for slab shots, you don't_want_one. Field of view is far too small to accommodate an entire slab. Heck, for insurance shoot the dang shots handheld with the kit lens, autofocus and IS. The slab itself establishes the grade/value; you don't need high-resolution studies of the individual coin contained therein. For raw coins and insurance purposes, you do want the resolution.

 

It isn't the fact that the 105MN is manual that's the issue, just that it won't go beyond 1:2 natively. Beyond that it starts to degrade in performance as extensions are added. Adding a teleconverter is actually a little better option as it keeps the lens formula optimized and magnifies the center portion of the image, where it is sharpest.

For lighting, what matters is the diameter of the front-most part, which is the 52mm filter ring on the 105MN. Mounted on bellows, the front-most part of the lens is what limits lighting angle. Most enlarging or duplication lenses have 40.5mm threads (some are 34.5, some even smaller), so you can get closer to vertical with them vs the 105MN.

Digital zoom is VERY important for critical focusing. When tethered, most programs offer a zoom function that lets you go to 1:1 or 2:1 pixel detail "live" for focusing. I could not shoot without this capability.

BTW, I am not sure about $5 for a 55mm Micro-Nikkor. Doubtful one at that price would be all that usable, but folks do get lucky. The 55MN is the best lens available for shooting Dollars, with the exception of the 95mm Printing-Nikkor.

 

Hah, I was on a conference call, typing away, and didn't check on responses before I pushed "send". SD beat me to it with excellent responses...Ray

 

I'll be danged. Until this moment, I'd always thought I was looking at a 100% crop when focusing zoomed in. At it appears, at least with the XS and Zoom Browser, I'm at roughly 106% instead, at least on my screen.

 

Thanks. Your response was more inline with what I was asking about lighting. I suppose I should have said light impedence or shadowing.

As for the 55mN @ $5, the only problem was the thread on the filter end was dinged. This was easily fixed by screwing a UV filter on the end, that straightened out the threading which made it usable with filters once again. There were no scratches nor fungus. Just the filter thread issue... so they're out there if you look.

 

Actually, the best values are lenses that have such problems. Collectors don't want them, and folks are often loathe to bid on them since they are hard to re-sell. Even if the lens has a bit of fungus or some scratches, these things have almost no effect on the imaging quality of the lens. So if you plan to use the lens, and don't want to spend much, seek out the problem lenses for best value. Just make sure you can return it if it arrives in worse condition than was described.

 

Really? The 100% and 200% zoom functions in Live View are not really 100% and 200%?

 

Clicked right in without an adapter. Looks like the front takes some type of adapter similar to the camera body. No threads. This thing is really cool. Just came in today.

Sent from my XT1093 using Tapatalk

 

Then it's probably Canon EF-S on the other end - see if one of your stock lenses fits. That'll tell you what you need for an adapter.

I don't have "100% and 200%." Just the Zoom view at whatever mag it provides. I'm using a pretty old version of Zoom Browser, quite possibly the very first (the EOS Utility .exe is dated 2008). Heck, I don't even have it on optical disk any longer.

 

While I agree that a scratch or pit can be fixed with a black Sharpie, I disagree on the fungus issue. Once a lens is invaded, the issue gets worse over time. Also, it causes major imaging issues at telephoto distances. That said, for coin photography, you're probably right... and even if you aren't, you can crop the distortion out as a temporary fix until you can get the lens cleaned.

 

Fungus is easily killed with application of UV so that it won't get worse over time. Of course if it's between a couple of elements, and has completely invaded the lens surfaces, then it will degrade contrast a bit. You would be amazed at how much damage a lens can take before the IQ changes!

 

Especially in our end of the discipline. Not a single example of the "problem lens" set I bought (of the ones I was able to try so far) shows any artifacting capable of affecting the IQ.

 

Yeah, Dave. The seller was able to point me in the right direction for an adapter. I'm happy because the adapter I have coming can fit on the bellows or directly onto the camera body. Unfortunately I just missed the end of the auction for that nice copy stand. It went for $44! Just insane.

 

You can make a home project copystand on the cheap. You need:

Base: 1/2" particle board works. Paint 50% gray, 0% white or 100% black, according to taste/need

Metal attachment: two pound piece with appropriate holes and nuts/bolts to secure in place

Post: 24-36" metal pole to attach to base

Joist and screw pole: basically a 90 degree attachment with a bolt and lock nut to attach to screw hole in base of camera

Total contraption should cost about $15-$25.

 

What a great article! I use a Canon Rebel Eos XS Rebel I purchased with my first social security check. My macro is a Canon EFS 60mm. I do have the problem with sharpness which I have been pulling hair about. I love the Canon software that comes with the camera. Still I'm always questing for new ideas. Thanks a lot.

 

Very interesting and informative thread. I've got a little-used Vivitar Series-1 90mm macro lens with a mount for Nikon film cameras. It's f2.5 and will go to 1:2; I think it was actually made by Tokina Would it work well for coin photography and how could it be adapted to a Canon Rebel XS? If a Rebel XSi can be obtained for about the same price as an XS, is there any reason not to go that route? I know it has 2 MP more, but will it work as well with Live View?

I've had some experience with biological macro photography back in film days. Coins are a different ballgame with reflectivity being a big issue. Mostly I want to do slabbed $2.50 through silver $1 in size. I've got a Technal copy stand and axial lighting system, but the Nikon Coolpix S8100 is the problem.

Cal

 

See the attached chart comparing XS, XSi, and XTi cameras.

Your "Bokina" macro lens works very well for coins. Do you have the 1:1 adapter? Without the adapter, you can achieve 1:2 magnification. You need the adapter to get to 1:1.

 

Thanks Ray. You and Dave are very helpful, and I'm thankful for it. No, I don't have the 1:1 adapter. When I bought the Bokina many years ago, it was for portraiture. However, the adapter is an extension tube with a coupling for Nikon aperture info and a tripod/stand mounting bracket. If I use the lens with a Canon body, any extension tube of the same length should do. Right?

I can spend more and get an unused Rebel T5 body at a really good price. I'd have more MP and a warranty, and don't mind the expense. Any reason it wouldn't be as good or better than a XS or XSi for coins?

Cal