Magnifier, scope vs enlarged (resized) photo?

Just curious, but how well does a resized (enlarged) image view of a good photograph stack up against a good microscope or traditional magnifier? Seems to me that if you start with a quality photo, the convenience of using the digital view might outweigh the traditional analog methodology of a scope or magnifier.

 

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Digital pictures are made up of pixels, each of which is a colored point. If you quadruple the image size (double both the height and width) you're also quadrupling the pixel size. This means that a 2048x2048 pixel size picture for which the height and width are doubled will have an effective pixel size of 512x512. If the size is tripled in height and width, the effective pixel size is 256x256. Every time you enlarge the picture you enlarge the pixels and you lose resolution, so enlarging to see more detail doesn't work; you still have the same detail, it's just blockier.

 

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I'm not a photography expert, but I have seen plenty of digital enlargements and all I see is pixels.

Chris

 

One of the reasons so many see "DD", RPM, "Magical dates", etc. USB-BAD

 

Makes sense, so not for VAM work, but still some limited value for a set of old eyes, like me at 62 trying to read the date on a half dime or a 3 cent silver piece.

 

ZACKLY!

Chris

 

I think it depends upon the quality of the photograph and the subject matter being photographed.

The major point in identifying some varieties is how well light can be directed onto the subject variety. Put the light source in the wrong location and regardless of how high the photographic resolution, the variety will be nearly invisible.

This is one reason why I like my Stereo scope. I can adjust the angle of the coin to optimize the viewing of the variety for photographing.

The downside is that my Stereoscope is to heavy and bulky to wear around my neck at coin shows.

Traditional Magnifiers are only as good as the light source provided to them. I only use my loupe to possibly identify. I use my scope to verify.

As pointed out for enlarging digital photographic images, the enlargement is only as good as the image.

 

Can't help you showing with a scope but with enlarged photo vs magnified lens on a Sony RX100 (20 megapixels) camera of an antique pocket watch. Enlarged 100%.

This is enlarged photo.





This is with the magnified lens (6x)




Hope this helps.

 

This is where a high megapixel camera, and a quality lens comes into play. It's also about the only time it does - enlarging.

****This was done quickly, and I missed focus by a hair, not to mention it was shot through a slab****

Attached are two images taken with my lowly 15-Megapixel Canon 50D with a Canon 100mm Macro (non-L). Both photos were brought into Photoshop, and zoomed to 100% (actual pixel size), cropped, and saved full size. This is called a 100% crop; a crop that shows the image at pixel level. If you go larger then a 100% crop (150%, 200%, etc.) is when you start seeing the blocky pixels. Anything at 100% or lower will not get blocky.

The first image is at full resolution (15MP), and the second is at the smallest resolution (3.7 MP). Essentially, there is a 5x difference in view between the first and second, so you can get (almost) 5x 'closer' at full resolution. If you have a 30MP camera, you can get twice as close as I can (with the same lens).

100% crop @ 15MP:



100% crop @ 3.7MP:



If you enlarged either of these from the sizes they are, your image quality will go downhill rapidly.

In both, you can easily see the die polish lines, and just about anything else you wanted to see, but the greater the MP, the greater you can enlarge (zoom in) without loosing image quality. And if this coin wasn't slabbed, the image quality would be there. (Which brings up another point I'll get to later)

Now to get macro photos of coins, it's pretty difficult to do without a tripod, and without proper lighting. Your depth of field (range of acceptable focus) at 1:1 macro levels (which this is really close to) is fractions of a millimeter, depending on your f-stop. Without enough light, you may end up shooting at f/2.8, which would most likely result (in this case) the cat's snout being in focus, but the fields not being in focus, or vice verse. These were shot at f/16, so there was enough dof to capture both. I also use the self timer to avoid any shake (you could also use a remote shutter trigger).

So to address @SilverWilliesCoinsdotcom 's question, I prefer the digital camera setup for at home, and a Lighthouse LED 10x loupe 'on the road'. The advantage of the loupe is I can easily rotate the coin or the loupe so the light hits the coin from a different direction, and it's quick. I thought about a microscope, but decided in the end against it, because with a decent amount of megapixels, you can exceed the magnification of most scopes. Looking at the above images on my screen (15" laptop), I'd estimate the enlargement to be close to 200x from the actual coin. If I was looking through a scope at 200x, I'd have to sit looking into the scope until I was done, which I believe would just be annoying to my eyes after a few minutes. I can also take multiple 1:1 images, and stitch them in Photoshop, and get the full coin in view, and zoom in and out as I wanted to, which I think is easier then moving a coin around under a scope. The downside to the camera setup (in general) is it's relatively time consuming. It takes about 3-5 minutes to do both sides of a coin (never actually timed it), and then I have to move the images onto the computer. Huge advantage is that once I've done it, I never have to do it again, whereas with a scope, if you put that coin away, you have to do it all over again to see it under the scope.

I think (and I really don't know, as I don't own a scope, but used them in school), you may not be able to use the scope on a slabbed coin. Scopes have very little 'working room' between the subject and end of the objective that you may not be able to get close enough on a slabbed coin. I may be wrong on that, and I'd like to hear if I am. If I'm correct on that, that is a huge drawback to a scope.

Also. with most consumer grade scopes with digital capabilities, the image quality (IMO) is mediocre at best. Yes, some of you scope owners have produced some spectacular images, but for the most part, they seem to be lacking.

And just for S&G's, can anyone tell me what coin I used above?

 

Any enlargement not based purely on optics or larger sensors is going to obscure detail, not improve it. If you could add pixels via software and come up with a sharper, more faithful result, you would become the richest person in software development and the megapixel war would end since we'd all be using 2MP cameras.

If you want more detail or larger images for older eyes (I feel you on this), you either need more optical magnification or more megapixels in the camera. And the latter can force you into better lenses, as it exposes the faults of the lens you're currently using. The advantage of observing the image on one's computer monitor can't be overlooked, either - I can only see half of the coin on my monitor, when showing the image actual size from my camera.

Even an older 10MP image from a camera like mine is still nearly 2500 pixels round, and my high-resolution monitor can only display 1440 pixels vertically. That's because individual pixels on a digital camera sensor are microscopic, and pixels on a computer monitor are only 100 or so to an inch. Still too small to be grainy in a sharp image, but huge compared to the camera's sensor.

Using software to control the camera via mouse and keyboard, I haven't used a magnifying glass or the camera's viewfinder for years. The camera is my loupe, and by adapting microscope objectives to it I can achieve magnifications as great as any dedicated microscope.

 

No sweat!

1927 Vermont Sesqui Classic Commem

Chris

 

Correct! Glad to see some know their commems!

 

The snout was a dead giveaway. Yeah, I was working on a set in MS65-67 until my financial situation changed.

Chris

 

Almost all modern digital cameras of any quality make images that must be reduced in size before posting on Coin Talk. You can always piece together an image using a crop of important features before reducing the whole or you could even shoot a tiny part of the coin detail as best fits your needs. All you have to do is learn to use our camera equipment and decide what fits your collecting style.

All parts of this image are reduced from the original shot with a Canon DSLR. The inset parts were not reduced as much as the whole but even those small parts were too large to post directly. You can always reduce images and retain quality. It does not work the other way around. Click to enlarge this image (a little).

 

I used the wrong photo for the enlarged photo. It should have been like this.

This is the enlarged photo, 100% (no magnified lens)





This is with the magnified lens (6x), 100%



Sorry 'bout that.

(I have 1x, 2x and 4x magnified rings and can go from 1x up to 7x, however, the 6x is a little sharper than the 7x.)

 

Just to be clear, are you talking about diopters or so-called "close-up filters"?

 

They are Close up Lens or Filters.

 

When I started doing digital coin photography, my goal was to take clear enough images with high enough resolution to be able to "zoom-in" and see variety details like RPMs, Doubled Dies, Die chips, etc in high resolution for attribution and documentation. I was hoping an overall image of the coin could be taken with high enough resolution for this. But so far, I have not achieved this goal. To view details in high resolution, I still resort to using higher power optics. The result is much better than can be achieved with any magnifier or loupe, but requires a separate photo be taken with different optics.

My standards for this goal are very high, and indeed some of the overall images I've taken have given a "good" result at the variety detail level, on-par with what can be seen with a good magnifier or loupe. So I guess my answer to the OP's question is "yes, zooming-in on a high quality digital image can be comparable to what you can see with a magnifier or loupe".

 

Thank you.

In the earlier days of digital, perhaps starting in the very late 90's to early 2000's, I used them as well even if not always in an ideal situation. I am surprised, though, by the fact they're not often mentioned here, especially in threads where someone already has a suitable camera and is looking for cheap options. Not a perfect solution by any means, but due to the very low cost, they're certainly worth considering for those needing to shoot a few coins every now and then and/or doesn't want to invest (time, energy, or money) in other options.

 

Well said.

And the reason I use them. At my age, it's not practical to invest lots of money on equipment. These lens and a decent camera (Sony RX100 in my case) does very well for my needs.

 

Rather than use additional magnifiers in the filter ring, I use with my NX1000, 3 different extension rings ( they maintain the auto features of the lens). These are the same function of extension tubes or bellows, but less expensive than a macro lens. I use these more with gemstones than with coins, as I can manage the light and manipulate adjustments easier. It also eliminates the 'faults' that may be in the filter ring magnifier lens. Jim