How make those extremely Closeups of Coins

Ok back now .. yeah -5 ev with 1/125 shutter speed .. had to use the -5 or Histogram showed almost everything clipped

 

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BTW @rmpsrpms I really appreciate your recommending the LED Lamps ... much much better than I assumed

 

@rmpsrpms do you use a Canon or Nikon?

 

I use Canon for coin photos. I would not use anything else due to the partial electronic shutter feature (EFSC).

My walkaround camera is a Nikon. I have a bunch of Nikon lenses.

 

I committed years ago when purchasing the lens ... just got the D7200 from a D70S .. Sounds like Canon as better coin type features ...
I am looking at the Histogram, do I want to limit the amplitude of the graph and does that mean the shutter speed would need increased if these spikes are clipped?

 

If you are needing to reduce to -5EV then something very odd is happening. It sounds like the camera is not metering properly. What metering mode are you using? If you change modes, do the exposure values change? I have rarely needed to go more than -1EV to eliminate hotspots. If I have to go further, it usually means my lighting is not diffuse enough, causing too much contrast.

 

I was wondering about the -5 EV also .. not real sure why either. I have a new image of the Lincoln 1960D with the new LED lamps in second .. I when to another style I think this camera may be doing some auto something or other .. just not sure what yet

 

Where is Shutter 1/25 f1/14 EV0.0 Aperture Priority with ISO 100

 

Looks a little over exposed in hair but color more closely identifies than last photo yesterday. Good detail of doubling on Liberty and IGWT with AF on
I set the Temp of those bulbs at 3200 ... hope that is correct

 

You don't need to worry about the amplitude of the spikes on the histogram. They just indicate how many pixels have the corresponding level. You'll get clipping if there are too many pixels "off the right" of the histogram, which shows up as a big spike at the right-hand edge. If there's a spike at the left-hand edge, it means you're losing shadow detail. You want the curve of the histogram to just reach the right and left edges, but drop to or near zero at each edge. (Unless there are bright or dark areas you don't care about; if a background is brighter or darker than the coin, it makes sense to over- or underexpose the background. You're using a good grey background, so that shouldn't be an issue for you.)

 

the background is white that is why I was wondering. Thank for the info on the right and left of the Histogram have been thinking about that as we speak ... How can to tell from the Histogram if you are over exposed? Or can you

 

Ok here goes my last photo of this coin unless someone tells me something is wrong. IMHO this coin is a Definite Red MS 64-65 with DDO seen @ Liberty and IGWT if you zoom in. It was taken with a Nikon D7200 Micro Nikon 105mm Lens set at a slight angle facing away from Camera. Was using 3 LED Lamps set at 10,2 and 6 o'clock (These are what really allowed the color they are 60W versions) set to a Color Setting 3200. f=1/18 EV=-1 2/3
Auto Focus On, 9" Lens to Coin
Hope I got everything. An especial thanks to all that made this photo possible. Different type coins will require different setups but this one can be a starting point for all interested

 

Zoomed in LIB

 

A few pictures might be worth a lot of words here.

Here's a pretty well-exposed shot, with its histogram:

That big spike corresponds to the cardboard of the 2x2 -- in the full image, it occupies most of the pixels, and it's all mostly the same brightness. There's a tiny spike off at the right, because a very few pixels are overexposed, but they don't really detract from the image. There's also a spike to the left, representing the gap between the coin and the 2x2; I don't care about that gap, so I don't mind that it's underexposed.

Here's an underexposed image:

Note that most of the area under the histogram is pushed off to the left. It's not actually clipped off the left -- the pixels haven't gone all the way to zero -- but it looks dark, and it's harder to see detail.

Here's an overexposed image:

See the spike to the right? Much of that is the 2x2, which we don't care about, but we're also starting to lose detail in the highlights -- they're getting clipped to the maximum possible value.

Here's a badly overexposed image:

Here, most of the histogram's area is shoved over against the right edge. We're losing a great deal of detail in the coin.

To maximize visible detail when you're adjusting exposure, you want to see a histogram that's well-distributed, without leaving a lot of empty area to the left or to the right. Keep in mind, though, that there may be areas of the image you don't care about, and pushing them off to the left (if they're dark) or the right (if they're bright) is fine.

 

Awesome work, jeffB.

 

Thanks for explanation I am sure that will help a lot of people wondering some the same things I did

 

I've been pricing and shopping scopes recently, too. I'm sure you know this, but just for the benefit of anybody else looking for a scope, I thought I'd throw in some of the info I've found in my searches.

You also don't want your minimum magnification to be too high, and, ideally, you don't want to have to switch objectives to get your maximum magnification. I like the minimum magnification to be no more than 7x, but 10x is acceptable. Even 3.5x is totally fine.

I agree that 80x is a practical upper limit.

Haha, try a Panama Pill! It's 2/3 the diameter of your 10 cent. Good to know that sometimes autofocus doesn't work well on small coins, however.

 

It is important to research what factors inform the advertised "magnification." You'll find most 'scopes have verbiage mentioning the "magnification" is also related to your monitor's resolution and size and the sensor employed; they're playing the "monitor magnification" card we've discussed in regard to digicam photography. The actual optical magnification is going to be much lower, and you might find that the unit employs a very small sensor and/or relatively little optical magnification.

5X optical magnification is likely as much as one would ever need to employ with a dSLR-quality sensor. True 80x optical magnification would be utterly useless for a coin. It would create an image of a Half Dime (on a 24MP camera) something like 300,000 pixels in diameter, which would require a monitor of the same pixel density as my (high-density) 2560x1440 27" to be roughly 250 feet wide to display the whole coin.

 

Sorry, I didn't specify: I was referring to 100% optical scopes, not digital scopes. You're correct that magnification other than straight up optical magnification is useless.

You don't shoot an entire half dime at 80x. You'd be zooming in on a tiny portion of a letter or something, for a variety pic.

 

If you were to magnify a portion of a coin the monitor would not need to show the entire coin if you were looking at a 1/2 Dime let say. Should you only show a Die Crack of the same 1/2 Dime you could zoom into that portion with a 20x or so magnifier then it would display well on a smaller portion monitor. Say like a 2000 pixel monitor .. I think that would be were a microscope magnifier would be helpful. Looking at larger type coins like Morgan a magnifying microscope would be over kill .. at least that is what I think