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

I've been known to hold forth occasionally (um, every possible occasion, appropriate or not) on the topic of inexpensive coin photography. The work of rmpsrpms a few years back converted me from an "expensive dSLR/equally expensive macro lens" shooter to a "cheap dSLR/bellows/duplicating lens" photographer, and I haven't looked back.

In a nutshell, without getting too technical: An inexpensive, earlier-generation Canon dSLR - Canon because of their Electronic First Shutter Curtain eliminating shutter shake, and their free bundled Tethered Shooting software - in conjunction with a bellows for variable magnification and easy focus, using an older film-oriented duplicating lens, is a combination unbeatable for price and professional-level image quality. Older dSLR's with smaller (in megapixels) sensors are more forgiving - the larger pixels on the sensor help hold off the onset of diffraction, which is an enemy trying to defeat our quest for sharpness.

The "sweet spot" was, back then, and still is, the Canon Rebel XS (1000D). It was a 10MP, slightly down-market version of the 12MP Rebel XSi introduced in 2008. It forms the basis of what we publicize as the "$400 photography rig," a minimalist combination of pieces - purchased mostly used - which combine to provide results as good as an expensive camera wielding a $500+ bespoke Macro lens.

Of that $400, approximately $175 was budgeted for the purchase of the Rebel XS, because that's what they cost used back then. The camera I'm about to show you (and used to shoot the images posted here) cost me $84 from Adorama a few weeks ago....meaning the "$400 rig" is now closer to the "$300 rig."

So here's the setup, with the new piece of kit which caused this thread mounted:



Yes, my workstation is cluttered with stuffed animals. Sue me.

The stand upon which this rig mounts was custom-built for my by rmpsrpms, and would break the $400 budget, but you can achieve the same capability with anything from a $20 tripod (sacrificing ease of use) on up.

I was casting about for a lens more suitable to the smaller coins (mostly Lincolns) I'm acquiring these days, meaning I could get away with a shorter focal length than the 75mm we usually use for Crown-sized coinage. The goal is to fill the camera's sensor with the coin; a Morgan, for instance, is about 0.42x magnification (which is why I chuckle at USB microscopes offering "200x magnification.") That means a 38.1mm Morgan has to be a little less than half-size to fill a 14.8mm APS-C sensor. A 19mm Lincoln, therefore, requires a magnification of about 0.78x to fill the same sensor. Technical reasons aside, this allowed me to consider 50mm lenses. Now....

If you're actually interested in coin photography, open this website in a new tab and don't go to sleep until you've read every page there:

http://www.coinimaging.com/index.php

That's Mark Goodman's place. You're not as good a coin photographer as he is, and neither am I.

Over the last few years he's gotten into testing various lenses for their suitability to coin imaging. He's amassed a large number of lenses tested, in many focal lengths applicable to coin photography, among them the finest (and most expensive) nontraditional optics on the market. We know the Canon 100mm Macro (and similar from other manufacturers) are plenty sharp enough for our needs, but there are other choices as good or better, in most cases available for a lot less money.

Here's Mark's "Hall of Fame" page for the lenses he's tested:

http://coinimaging.com/hall_of_fame.html?

I went there (do so yourself, to follow along), and looked at the higher-placed lenses optimized for 1x magnification. The Printing-Nikkors are, of course, at the top - they're kind of in a class of their own, and will set you back about $2000 for one - but also highly-placed is the Rodenstock APO-Rodagon 75mm 1:1, the "relatively inexpensive" duplicating lens considered the best of the ones which won't be the only toy you can afford that year. You can find them for less than $300 used, and at $225 buy one if you see it.

But that kinda defeats the purpose of "cheap" coin photography, and keep in mind the worst lens on that list will still give you a rep as a "professional" in these pages. The El-Nikkor 75mm listed at #25 in the "Overall Ranking" is the recommendation of choice; you can usually find them (they're plentiful) on Ebay for $40-ish, well within the budget of the "$400 rig." I, myself, have been shooting with a $20 El Omegar 75mm, and haven't gotten many complaints.

I went through that list looking for the best of the bunch available for less than $100, and one stood out. It's #10 in the overall ranking, and posted a Sharpness score even exceeding the vaunted Rodenstock. That lens - the Schneider Kreuznach Componon S 50mm f/2.8 - is what you see attached to my rig above. I got it for less than $70 shipped on Ebay, and it was on my camera shooting images ten minutes after I walked in the door with it.

I couldn't perfectly duplicate the lighting situation for best comparison, as the working distance of the 50mm was almost halved from the 75mm, but I did the best I could. Here's the result. The first two images are from the 75mm El Omegar, and the second pair from the Schneider, same camera, same place, same two Jansjo lights. As usual, everything was shot tethered to the computer - I manually-focused at full magnification from what I saw on the monitor, made all setting adjustments and triggered all shots with the mouse.

El Omegar:




Schneider:





Here's a comparison of the 100% crops, which are a hint as to the actual size of the original images this setup creates.

El Omegar:



Schneider:



The difference is marked. To me, the Schneider is in a different league, while remaining affordable. If you throw the money saved on the now-cheaper Rebel XS into the more expensive Schneider, you've just seriously upgraded your capability.

And keep in mind, with the bellows you can basically set the magnification wherever you want, and it's just as easy to acquire a microscope objective for well under $50 that will screw right on and give you all the magnification you could ever need for the tiniest of details. I wouldn't hesitate to double the magnification with either of these lenses and expect decent results. And with this rig, you can roll search to your heart's content, live on your computer monitor, at any of these magnifications. If what you see above isn't large enough for you yet.

The takeaway? You can duplicate what I'm doing here for $400 or less.

 

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Thanks for the write up, I was looking at a Rebel xs the other day, though I had no idea about lenses. You make it sound easy, some of us need someone to tell them what works, for, the pics that they want to take. I have spent countless hours in Camera stores. I havn't had anyone lead me in the right direction. Nice pics!!!

 

Thank you.

Let's make no mistake, easy isn't happening here unless you find learning and scientific procedure easy. One cannot leverage this technology without learning the nuts and bolts of how photography works, the basics of file management on a computer, and certain aspects of postprocessing. It comes readily to some, and with more difficulty to others. Me, I'm obsessive....um, detail oriented, and didn't have much problem picking it up.

Still took me a good year to get it right, on my own. This is partly about helping others not have to learn it on their own.

 

I will definitely be giving it a try. Post processing?

 

Postprocessing to the extent of cropping and downsizing - both in physical size and filesize (hence the file management reference) - for online posting. You can't just throw a 2500-pixel image into CT.

Also, possible manipulation of color/hue/saturation, and maybe a little Sharpening, Levels and Contrast as necessary. They let you not worry about wringing the last 5% of possible performance from the lens while still coming up with something faithful to the in-hand look of the coin. I came to coin photography from a fairly extensive background in processing of this type, and probably resort to it too freely.

It bears mentioning that it's sometimes difficult to recreate the "in-hand" look of the coin with a digital image. Not because the camera is failing, but because you don't usually look at the coin in-hand using the same lighting setup as you image it with. You'd find it more similar if you only ever look at your coins in a darkened room under very close direct lighting, just like you shoot them.

 

Great write up, will look into this.

 

Is there a thread of the month button? Great research. I have Goodmans book and have read it. I haven't rounded up a copy stand yet but I want one pretty bad. I have a Canon S3 that I used to do most of my photography with but we have an under used xti now. Will this Schneider lense fit it as well you think? Are the threads universal? I'm loving that lense.
Is that pic of the wheat ear an enlarged image of the original pic or taken with the camera? It is a big difference. I want one now. Thanks for doing all the research.

Sent from my XT1093 using Tapatalk

 

Thanks, Being that I am a 4 gen Carpenter, some of these terms dont make sense at first, I have a couple of books on the way.

 

Ok just read it. 100% crops.. That answered that

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Vess1, the XTi is one generation short of being able to use the tethering setup - it lacks Live View, which is imperative to real-time viewing. It would make this whole process far more cumbersome and frustrating to have to try and manually-focus with only your viewfinder as a visual aid. That's why the XS is the "sweet spot" - it's the oldest and cheapest of the Live View-enabled Canons, essentially the XTi's sensor with the newer firmware.

Threads vary with these lenses, but there's an adapter available for just about anything. Part of the learning process is understanding the thread types and what you need to connect one component to another. Differing bellows use differing threads/mounts, as well. The Schneider (my example, at least) uses the Leica M39 (mm diameter) thread, and the bellows an M42 thread; I have a little adapter ring which works between them. Another adapter at the top of the bellows connects its' M42 to the Canon EF mount on the camera.

M39 (39mm x 26tpi), M42 (42mm x 1mm thread pitch) and C-mount (1.0" diameter x 32tpi)) are the most common.

 

Ok so I didn't read it all... but when I think bellows and camera, I think this...

 

Very nice SD. The 50mm SK definitely blows the El-Omegar away.

The only issue with 50mm lenses on bellows is they will limit the max coin size you can image. For most bellows, 50mm will limit you to Halves, or even Quarters, as the largest coin that can be framed.

So the advice is if you want to try 50mm lenses (which are available generally very cheap for entry level to get your feet wet) you should pair them with short-extension bellows. I've built a few setups for folks using 50mm and 63mm lenses that could only go up to Nickels, but they were Cent collectors and didn't care at all.

Two final notes...first, shorter lenses mean more compact setups because the working distance is also reduced. All dimensions scale with the focal length. So this means if you can get a short bellows that allows framing the largest coin size you care about, then the whole setup can be very small and compact. Desk-friendly...and second, shorter lenses give you more flexibility in getting higher magnification for variety detail imaging, for the same bellows extension. 50mm is a nice focal length that can allow you to get up to 2:1 with most bellows. A good quality 50mm like the Componon-S lends itself to use with a 2x teleconverter while still giving good sharpness. This means that you can achieve up to 4x magnification with the same lens you use for full-coin imaging up to Dollars! What a flexible setup.

 

Nice write up SuperDave!!

Both @SuperDave and @rmpsrpms really know their stuff. I bent rmpsrmps' ear over on another forum for equipment recommendations. I came from a photography background which made getting into coin photography much easier. What I had never used were the enlarging lenses, bellows and focusing rails before. Those two made that transition very easy. The trickiest part of the whole thing for me, and still is, is the lighting. Lighting through a slab is one of the most difficult aspects of this endeavor, especially for toned coins.

If you have any questions or concerns, I am very confident SuperDave and rmpsrmps will be more than happy to help you.

 

I love these coin photography threads, particularly the "cheap" ones. A photo rig is on my list of things to acquire soon. What if one was interest in investing more than $400 into equipment? I'm assuming that most, if not all of the extra money up to a certain point would go into lenses, right? What if I wanted to shoot truly huge coins, like 50, 60, or 70mm diameter, as well as truly tiny coins like 5-10mm diameter? Could all this equipment be kept relatively wallet- and desk-friendly?

 

I'm more scared that sponge Bob is gona bite me

 

Actually, this is about the limit of what it'll frame on the bellows (pulled from my pocket to illustrate, no real attempt at "proper" lighting):



That's with the bellows completely collapsed, and all I can fit onto the sensor. But, who really needs a bellows?

Maybe if I use my shortest spacer (15mm, I think) and no bellows....

....yeah, that works.



That's about 41mm worth of coin on about 11.5mm of sensor - I got about 80% fill - so about 0.28x, and I still have 2000 vertical pixels of coin on the original. Working distance was about 230mm, all kinds of room. Yeah, we can do a Dollar with this.

 

OK, I edited my post a bit since the bellows is not being used due to too-long minimum extension.

This does go back to the original kit list for the "<$400" setup, which did not have a bellows at all but a 17-31mm helicoid plus mixed lengths of fixed extensions. That works well on your Santoku stand or of course on a tripod or simple copy stand.

 

I have like 10 of the Russian 5 kopek coins there nifty heavy copper

 

Note the size of the Componon relative to the camera. These duplicating lenses are only a couple inches in diameter and an inch and a half long or so. You can fit a lot of them into a small space.

18"x30" is enough room for everything I need to shoot, including elbow room for the lighting and lens storage.

You don't really get the scale of the image sizes these rigs shoot at until you (try to) look at them on your screen. Only the very highest-resolution monitor currently available - Dell's 5k at 5120x2880 - can show a 12MP image fullsize. A duplicating lens optimized for 2x will take the smallest Lepton and turn it into a screen-filling monster you have to downsize by two-thirds just to post here.

So, two or three - at most, I don't know if a 75mm could be made to image larger medals; Ray would have the math off the top of his head - lenses, plus an objective for when you really want to fall off the cliff ( ), and you're in business.

Contemplate the effect sensor megapixels have on "magnification." The bigger the sensor, the larger in pixels the final image is (assuming you're getting 1:1 on the sensor, which is the goal), and the greater the apparent magnification because you're looking at it on a monitor. The 2592 vertical pixels of my XS becomes 3456 vertical pixels with the exact same optical magnification, and if you go nuts on a 24MP 750D that becomes 4000 vertical pixels. That approaches "who cares if you fill the sensor, it'll still be huge" territory.

So, you can increase the system's ability greatly by acquiring a newer camera with higher megapixel count; that's the first way to increase the budget. Such sensors are less forgiving of optical and lighting imperfections, though, and have an effect on the aperture at which diffraction begins taking away sharpness (as does magnification, but that's all for a later lesson ). So you need more exacting technique and optics, possibly including focus stacking, therefore more learning. This Componon is up to a big-megapixel camera; I don't think the El Omegar is.

Past a certain investment level, it becomes worthwhile to just consider a bespoke 100mm-ish macro lens enabling you to autofocus (none of the 4 Canon 100mm's I owned ever failed me with autofocus, even through a slab, and boy does that make the process easier) and dispense with the bellows completely, maybe adding an extension for a little more magnification. The whole point of all of this is to keep the investment level fairly low.

You could always have Ray build a rig for you, which means it'll be finely-tuned for your needs and working perfectly right out of the box, with no legwork regarding component acquisition. If I was in the mood to increase the budget somewhat, that's the way I'd go.

 

Spongebob is staring into my soul