Featured Coin Photography: Lens Commentary using Nikon D7000

Coin Photography:

Lens Comparison using Nikon D7000​

Objective: To find a better lens to replace my Sigma 50mm prime, or to determine if the lens is not the problem. The resolution of the Sigma 50mm prime was fine on the D70, but it just does not appear to make take sharp images using my D7000, tripod, and fast shutter speed. They are soft, and also the focus gets distracted by my aperture range (5.6-8.0) by scratches on slabs. I don’t appear to have enough resolution to be able to tell by manually focus past the scratches. It may be the lens, or it may be something in my current setup. My goal is to determine if the Nikkor 105mm will show a clear difference, with no other changes to the coin photography setup. Likewise, I will test my other lenses with the same setup, using a single coin so users here can see the differences.

Caveat: This is not meant to tell you the “right” way to do coin photography. All you would have to do is a simple search on CoinTalk to know that there are many members here who produce far superior coin photographs than I. This is simply meant to share my setup and observations with fellow members on my quest to better my own coin photography, and maybe teach a thing or two to someone just starting out. Use this post for new ideas or to do your own testing, or just for curiosity’s sake. As many people will tell you, probably 50% of what makes a coin photo great or terrible is the lighting, and I don’t really plan on talking about the lighting much at all, so this is also not meant to be all inclusive.

Hardware:
Nikon D7000 (see replacement, the D7100)
Manfrotto 055XPROB Tripod / 496RC2 Ball head
Lightroom 5 (LR 6 will be coming out soon)
Long USB cable (for tethered capture)
White/Gray card (photo background and to set white-balance).
2 goose-neck lamps with Spiral Compact Fluorescent (19watt / 75 watt equivalent)
Dell Precision T3500 (see replacement, the T3610)
Crappy Dell 27” Monitor

Camera Settings:
ISO 100 (NO auto-iso)
Aperture priority, f5.6 or f8
"PRE" white balance, set using coin background (gray card).
AF-S (single servo) focus
single center focus point above the coin face
Matrix metering mode (The camera bases exposure on the entire frame)
sharpness set to +9
Flash Off

Setup: Camera is setup on tripod to shoot directly down onto the coins surface. Tripod is leveled; camera on ball-head is leveled. White-card taped to top of table to prevent sliding. Coin slab placed in center of white-card. Long USB wire from camera to the front USB ports on the Dell Precision workstation. Lightroom open and “tethered-capture” started. Two Lights are arranged based on type of coin.

Workflow: Coin slab is placed on whiteboard and I check placement through viewfinder. (Live view would work too, but I greatly prefer optical viewfinder). I do not re-focus, as pressing the shutter release button in Lightroom will focus for me, and its already close enough based on the previous coin. I walk to PC, and click the shutter release button, camera takes picture, which pops up on my monitor a few seconds later. Use "AUTO" upright adjustment tool to make the slab perfectly vertical. I usually need to increase the exposure by 1/3 to 2/3 stops. I verify the photo is in focus, no parts of the slab are cutoff, and I adjust the lights until I get a representative photo of the coin. I crop the photo tight to the slab, and export using the following basic settings: Resize to fit 2000 pixels on long side, max 2.5 MB, 230 dpi and named appropriately for the coin in question. I repeat for the coins Reverse.

Lens Commentary​

Lens #1: (own) Sigma Normal 50mm f/2.8 EX DG Macro Autofocus Lens for Nikon AF. I've owned this lens as long as I've owned a D70, which is just about 10 years. I've used it on the D7000 for the last 3.5 years, and around 100% of my coin photography is using that combo. Works well enough for full slab shots, and even close-ups. I think my coin photos are decent, better than most, but not great. It’s just not a tack sharp as I want it, and it does not produce the excellent results of some other CoinTalk members, so I know I can do better, either with a different lens or better technique.

Lens #2: (potential future purchase) Nikon AF-S VR Micro-Nikkor 105mm f/2.8G IF-ED Lens I am currently renting this for a week from a company I have used to rental cameras in the past: Lens Rentals . It’s on my camera as I type this. Sample photos below. I am not making any conclusions yet, just sharing my experience and collecting data (photographs). This focal length on a DX camera (vs. a full frame FX Nikon), means that I am really shooting at 157mm equivalent. That is deep into telephoto territory. When I remove my 50mm Sigma and replace it with the Nikkor 105mm, both of which are macro lens, this focal length gets me a closeup of the coin only, whereas the former gives me a full slab shot, with plenty of empty space on all sides. Normally, I bring the camera closer to the coin when using the Sigma, but leaving the camera at the same distance from the coin really allows me to appreciate the differences. If you have no idea what I am talking about, take some time and read these: Nikon DX versus Nikon FX and Pick a Size.

Lens #3: (own) Nikon AF-S Nikkor 35mm f/1.8G DX Len A great fast general purpose lens, but not really appropriate for coin photography in my experience. When not shooting coins, this 35mm prime lens is what I leave on my camera most of the time. A great affordable lens for family pictures.

Lens #4: (own) Nikon AF-S Nikkor 50mm f/1.8G Lens Another great general purpose lens, but not really appropriate for coin photography in my experience. Using the Sigma 50mm prime makes more sense than using this lens, and my trial and error with coin pictures has proven this, at least to me. I no longer even experiment with this lens for coin photography. When not shooting coins, this 50mm fast prime lens is what I use to shoot human faces, like my kids. A great affordable lens for family pictures.

Lens #5: (own) Nikon 18-55mm f/3.5-5.6G ED II AF-S DX Zoom-Nikkor Autofocus Lens This is the very affordable and quite good “kit” lens that comes with most Nikon DSLR. A ridiculous number of these great general purpose lens are out there in the world, whereas the 105mm rental I am testing, is a specialty lens, with a specialty lens price. This is a much slower lens, 3.5-5.6 depending on your focal length, but at the wide side, the 18mm can really suck in a whole room into a single shot. The narrower end of this zoom lens (55mm) is potentially appropriate for coins, but I have two much better lenses at that focal length, the 50mm Nikkor prime and the 50mm Sigma macro. Another great general purpose lens, but not really great for coin photography in my experience.

Lens #6: (own) Nikon AF-S DX VR Zoom-Nikkor 55-200mm f/4-5.6G IF-ED Lens A lens I almost never take out of the bag. I don’t really care for this lens, of the telephoto focal length in general. I don’t shoot wildlife, and I don’t shoot faraway buildings, and I am not a paparazzi looking to capture a celebrity in a comprising position. To me, this is the least useful lens I have ever tried for coin photography. Since it’s not a macro/micro lens, the minimum focus distance is so great, it is very impractical to use for macro work. I keep this around for kid’s baseball games, and even then it really is too soft for my likes. 4-5.6 is slow. Don’t even bother bringing this out for coins.

Lens' NOT tested, but potential choices (prime, telephoto, macro/micro):

Nikon AF-S DX Micro NIKKOR 85mm f/3.5G ED VR Lens
Tamron 90mm f/2.8 SP Di MACRO 1:1 VC USD Lens for Nikon
Sigma 105mm f/2.8 EX DG OS Macro Lens for Nikon AF Cameras

 

Sigma 50mm Macro Lens Samples, f5.6
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A few samples, but really almost everything I have posted on here is using this lens. (other than photos marked a seller pictures)

Nikkor 105mm Macro Lens Samples

f5.6​

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Here are some sample shots. I will take more detail comparison shots in the next few days and will add to this thread. I am still trying to "learn" this lens.








Initial assessment after only taking a few shots, I love how "close" the coin is to me when I am looking through the viewfinder, but I am not quite certain I have dialed in the correct settings. I think I need to play with AF-Fine Tune. I know this lens can produce sharper images.


What do you think?


More to come...

 

I am dialing in the lens. Now shooting f8 and using AF-FineTune -5. The default setting was mushy, I tried +10 and that was terrible. -5 and -10 are about equal, with -5 being slightly better. The D7000 in a bit famous for back-focusing.

Anyway, here is a new shot using the settings:

 

I find myself doing exactly that for exposure on almost every image. 1/3 to 2/3, but sometimes a full stop. I do this in lightroom after image capture, do you do it in-camera with exposure compensation dial?

 

I'll check into using liveview with tethered. I don't really care for liveview on my Nikon, and I'm a big fan of optical viewfinder, but you are correct that this is not ideal at all for dialing in manual focus.

Some Canon cameras do use AF-finetune, just like Nikon. See here: click me

 

What I dont like is Liveview through the viewfinder, like on the Fuji x100s and a bunch of others, or Liveview on the LED screen on my Nikon. Too much delay, even in super fast fancy view-view like the Fuji. (great travel camera by the way)

I have never done liveview through USB on PC monitor, but I will check it out tomorrow.

Lightroom is freaking great! You're pictures are amazing, so whatever you use is doing the trick.

 

I discovered last night that I cant shoot my Nikon through tethered capture and adjust the focus. via liveview. I can download another piece of software called ControlMyNikon to do this. I will install and test out in next two days.

http://www.controlmynikon.com/

 

Alright guys, Ill try manual focus, and then manual focus via liveview, if possible.

 

This is still auto focus, but a few more shots as I get warmed up:

1/250 sec at f/5.6, ISO 100, 105mm

1998 S HALF DOLLAR - KENNEDY, PROOF NGC SP 69 SILVER

 

Well I'm trying it, and I have figured out most of the control, but for some reason the quality of my liveview is so bad, that I cant discern if focus is getting better or worse. It is highly pixelated, is this normal? Here is a screenshot of exactly what I see, CLICK to make big. See all those jaggies? That is NOT from image compression, that is exactly what I am seeing live.

 

Back to normal auto-focus for now, I seem to be getting pretty good results. What do you guys think? Any major flaws (the photo, not the coin) ?




I am really LOVING this 105mm macro lens!