Photo test: With and without diffuser

adamlaneus

By 'diffuser', I mean a plastic milk jug that has been cut and placed so that it softens the light on the coin.


The diffuser floods the subject with light from all directions, usually giving a more complete and natural illumination. It reduces contrast.

This milk jug diffuser achieves a good balance, it is not completely diffuse light and still has enough direction to show luster.

There are slight differences in exposure between the shots; some more than others. That, too, impacts the color you see (gold coins especially).

Some coins benefit from diffuse light. Some coins do not. There does not seem to be any one recipe for a good coin picture when talking about different surfaces.



First photo without, second photo with diffuser.




(again, first photo without, second photo with diffuser)





(again, first photo without, second photo with diffuser)




(again, first photo without, second photo with diffuser)





(again, first photo without, second photo with diffuser)





(again, first photo without, second photo with diffuser)





(again, first photo without, second photo with diffuser)





(again, first photo without, second photo with diffuser)

blu62vette

I almost always prefer without a diffuser. What I really don't like is the lack of contrast.

MikeInFL

Great illustration!

I think you will find that in general, diffused light looks much better on circulated coins than it does on coins with remaining luster. When you use diffused light, you generally make a lustrous coin "flat" (technically, they lack contrast) -- and your comparative photos illustrate this very well!

mgoodm3

i find diffusion most useful when the coin is really shiny on the relief.

direwolf1972

I use the milk jug diffuser method also.

I have a gallon and a half gallon that I use (the light is diffused a bit different with each).

I usually shoot each side three times. Once with direct lighting, then slip my half gallon over subject, then slip the gallon over it for the last shot.

I've found that it takes very little additional time and I can pick the one that I best represents how it looks in hand.

doh

I much prefer withOUT a diffuser.

rgCoinGuy

I have pretty much gotten the same results. And I agree with Mark, in that I have had my best "improvements" using this diffuser method on Proof Coins.

adamlaneus

Here are some more sample pictures. Same coins.

The difference is that these coins have been lighted with a pair of flash units rather than a pair of incandescent bulbs.

Each flash unit is set close to the lens axis. Both units are aimed directly at the coins and very little light hits the coins through bounce effects. The two flash units produce a very bright "point source" of light. The diffuser is very useful to produce a softer look. When the diffuser is in place, the coin does not have direct line of sight to either of the flash units.

Without a diffuser, this flash illumination is very 'sharp' and capable of showing (highlighting is perhaps a better word) every hairline in a coins surface.

I let the camera choose exposure in each photo.

I did not brighten or adjust any of these photos. Had I cropped them and done the black background thing, I probably also would have pulled the brightness and contrast a bit.


I did not crop the images. Although this presents the coin differently, it lets you see two important things:

1) There is a color shift when using a milk jug diffuser

You can see that the milk jug diffuser is not entirely color neutral; it warms up the image slightly. I did not crop these photographs and you can clearly see that the white background of the slab changes color slightly between the plain (bluish) and diffused (reddish) photos.


2) The shadows made by the coin through the slab is different; softer with the diffuser and harsher without.

Not apparent on the ANACS slabs. The shadows are a good clue to how 'sharp' the illumination is.












































As you see, flashes should probably not be pointed directly at a coin, but bounced or reflected or diffused in some manner.

The lighting in the original set of photos, done with a pair of closely set gooseneck lamps with 60W incandescent bulbs...that lighting is already fairly diffuse.

messydesk

Nice illustration. I like diffusion the most on contrasty, lustrous coins, as it puts the dynamic range of the coin more safely within the range of the camera's sensor. For coins with little contrast, you don't want diffusion.