Photo lighting

[dougsmit]

I agree with your 'preliminary view' but point out that very small changes in coin position and light angle can move the glares to better or less acceptable places so it is still possible to find a middle ground.  I might suggest playing around with more soft bounced light and less harsh direct light.

[peterpil19]

With lighting placement, I have found that the farther the light source, the "shinier" or "contrasty" the coin appears.

The first image uses a very bright LED desk-lamp which is at its natural height from the coin.

The second image uses the same desk-lamp brought down so that it is only a few inches on to of the coin (slightly to the side so that the light indirectly falls onto the coin).

How far do others place their light source from the coin when taking photos?

Peter

[peterpil19]

Also, again, would like views on which photo you prefer.

Peter

[Robert_Brenchley]

The second. The first seems a little glary.

[peterpil19]

Thanks Robert,

Peter

[cmcdon0923]

I would assume that #2 more accurately shows the coin's true colors?

[peterpil19]

I would assume that #2 more accurately shows the coin's true colors?

That is correct.

The issue is with the kind of lamp I am using. Although it is a very bright LED it does not have that cone shaped head which seems to concentrate the beam of light. If it is too far away the illumination is too poor. I've worked out that I need it 10 to 15 cm away from the coin and that way I get less reflective surfaces.

The trouble with this particular coin is that it appears to have had some renaissance wax or something applied in a manner resulting in a very shiny patina.
I've never had as much trouble photographing a bronze coin.

Peter

[peterpil19]

Hi,

I have been experimenting with axial lighting. I have never used this technique before. 

The typical set up as I understand it from various sources on the internet is to place a pane of glass above the coin at a 45 degree angle with the light source perpendicular to the coin so that light travelling from the source is reflected directly onto the coin and then straight up towards the lens of the camera as though originating from there. This lighting method removes shadows from the image and makes legends easier to read.

Many of those sources also recommend blocking extraneous light by e.g. placing an object in front of the coin so it is not exposed to he light source directly other than as reflected from the pane of glass.

I have found that I like the photos when I do not block the light from hitting the coin directly from the light source i.e. so there is a combination of direct light and axial lighting.

I have illustrated this with 2 photos. The first was taken without blocking the direct light, the second taken, with an object completely blocking direct light from the light source.

Do others experience this also and use a combination of the two?
Or is likely related to the manner with which I have taken the photos and the preferred approach is not to have direct lighting.

Also, when do others use axial lighting? I have found it results in nicer photos for some coins but not others.


Peter

[dougsmit]

I see two problems with the concept as presented.  Much light is lost when using axial but there is no way to control the proportion of axial with the directional that spills onto the coin.  The direct seems to  overpower the axial in the sample.  Secondly, when we shoot with a pure and balanced axial rig, it makes no difference from which side the light comes into the mirror since it will be directed straight down.  The sample has the direct light coming from the left which does not look good on the obverse but is fine for the reverse. 

I have stopped working with axial but do use a mix of ring and direct which is similar but allows balance between the two since the lights have individual brightness controls.  I would warn that both lights need to have the same color balance or changing the relative brightness would introduce color shifts on only parts of the image. 

[peterpil19]

Hi Doug,

Thanks for your feedback. A couple questions in my reply below if you may.

I may need to try using a ring light for my digital camera.

Q1. In your experience do they vary greatly in quality? I have noticed expensive ring lights for DSLR cameras (several hundred dollars), and very cheap ones on eBay for both DSLRs and compact digital cameras (less than 100 dollars).

I am experiencing difficulty in settling upon a lighting set up that suits shiny bronze coins in particular. When I have direct lighting from above, it results in too much glare on parts of the coins making the photo look overexposed in those areas. The further away the light source the greater the contrast and whiter the overexposed areas.  If I angle the lighting to make the lighting more indirect I end up with flatter / dull looking photos in which the the direction the light is too apparent.

That's why I have attempted axial lighting. The axial lighting appears to work fine with flat highly reflective surfaces. I took some very nice photos of modern coins.

With the bumpy irregular surfaces of ancient coins I find I cannot get sufficient light when blocking off the direct source (presumably because much of that light is being reflected off the coin at different angles).

Q2. Do you have any suggestions on how to improve the lighting in an axial set up? Could it be the quality of the glass I am using (I took a pane of glass out of a picture frame). I am using a fairly powerful LED light by residential standards (1000 lumen). Should I invest in an even more powerful light source to reduce the loss of light?

Peter

[dougsmit]

I can be of little help since I only have one LED ring and am happy with it.  I know nothing about others and finding the same 'brand' of Chinese lights on eBay is not easy.  The important features are:
1.  Daylight color balance
2. Adjustable brightness
3. Sufficient diameter to fit your lens. 

The easiest way to soften light is to point the light away from the coin and light the whole room rather than the coin.  This requires more light or a longer exposure but, if your camera is solidly mounted, long exposures are not a problem.  The LED lights I have, both direct and ring are much brighter than necessary so I have them turned way down using the adjustable brightness knob.  The one I have is made for use on a stereo microscope.  The larger ones made for regular photography are overkill. 

http://www.ebay.com/sch/i.html?_from=R40&_trksid=p2380057.m570.l1313.TR2.TRC1.A0.H0.Xmicroscope+led+ring+light.TRS0&_nkw=microscope+led+ring+light&_sacat=0

None of the above are identical to mine but I suspect many or all could be used.  I can not suggest a specific one and have never used any but the one I have (AmScope model MIC 209).   I have no reason to believe it is better than any other. 

[peterpil19]

Thanks Doug,

I have given up on axial lighting for now as it makes my coins look unnatural, particularly the bronze ones.

I spent hours on photographing this King Philip AE bronze using different lighting set ups and settled on the following photo, which I like, other than the white overexposed highlights which I can not seem to avoid... Even if I turn the light away from the coin and increase exposure time, I still end up with washed out highlights. Perhaps it is a compact camera thing. I am now seriously contemplating a DSLR with macro lens.

Peter

[dougsmit]

While I would be the last person to discourage purchase of a decent DSLR, I'd call that an excellent image.  Glaring highlights are certainly a problem but, often, I find myself sorry I eliminated them too successfully making the image look unnaturally flat when missing specular highlights altogether.  When you hold a coin in hand you can wiggle it and move the highlights around so they don't blank out anything.  A still image forces you to live with them, try to position them in a pleasing location or lose the natural look they convey.  Each choice carries a downside.

If you position the coin on something just a bit adjustable (small lump of clay) and make very small changes in angle, you may find it shocking just how much change happens with how little movement.  At some point I tend to give up and move on to another coin.  When I return at a later date, I frequently wonder just what I was thinking when I shot the thing earlier.  We want to make the coin look good but not unnatural and not conceal faults.  People say they want photos that look like the coin in hand but I insist that this requires a decision on where the hand is located when it is defined as correct.  Both of the coins below have faults that need to show but not be overemphasized.  The billon Otho has fine field scratched right of the face.  The more silvery Septimius has a lamination behind the head.  I'm currently toying with the question whether one should be more sparkly and the other less so but it would be wrong for both to look the same since the coins are quite different 'in hand'.  I may not be finished with these but I have so many other photos more in need of reshooting that they are 'on hold' for the time being.

PM me if you want to talk about dSLR's and don't want to bore the whole list.

[peterpil19]

Thanks Doug,

Very nice photos.

In your photos, the white highlights are not so white and you can see the underlying color and detail (other than perhaps in the edges of the highlights).

That is the effect that I see in so many professional photos of coins that I cannot seem replicate myself.  In all my photos the white highlights are completely white and devoid of detail underneath. Changing exposure, how much light falls on the coin, the angle of the light etc. makes no difference to this. Even if I angle the light away so that there is a shadow over the coin, and then increase the exposure time, I still end up with white highlights...

Using the clay is a smart suggestion - I never thought of that. I've been using a little piece of tissue paper underneath to help angle the coin the way I want it.

I have sent you a PM re dSLRs.

Peter

[peterpil19]

Here's another photo of a coin which I have struggled to get right.

I have settled with this photo for now but plan to make another attempt shortly.
It is unusually shiny for a bronze coin. It looks like it has been re-patinated.

Its shininess combined with its round surfaces on the obverse has made it particularly difficult.
Per the previous posts, no matter where I position the light I end up with washed out highlights.  All I can change is where these fall on the coin.
Though I can fix it afterwards in e.g. Photoshop, I have decided to work with the strict rule that I will not alter photos once taken (even levels).

The first photo is mine, the second and third photos are of the coin as advertised for sale by the Vendor I bought it from. Though I prefer my photo overall (which is more representative of the coin in hand), the highlights on the Vendor's photos are more subtle than on mine and don't result in any loss in detail.

Peter

[peterpil19]

I have uploaded photos of a single coin with 2 different lighting set ups.
The first has more direct light.
The second has more indirect light which I achieved by diffusing the light using tissue paper.

Calling for any opinions - which photo do you find more appealing?
Personally I am leaning towards the second one.

[dougsmit]

I'll be difficult.  Obverse - second; reverse - first

This coin has a very great difference between the two sides.  The obverse is high relief an convex while the reverse design sits in a depression.  This make it likely that different lighting might be better for each side.

I might suggest shooting the obverse several times making little changes in the tilt so the highlights move to different places.  Some will be worse.  Perhaps one will be better.  Small changes in angle can make big differences.

[peterpil19]

Thanks Doug,

That's great feedback. I must agree with you - the reverse comes out nicer with direct light.

I will try something different and post more photos in due course.

Peter

[peterpil19]

An embarrassing number of photos later, I present 2 more attempts.

1 with direct lighting but less glarish the previous coin.

1 with indirect lighting, but with adjustments made to get slightly more highlighting on the reverse.

I used 2 lights for this coin - one on each side. With only 1 light I found the obverse looked flat. With 2, the obverse looked more 3 dimensional.

Doug - I envy the photo you posted above. All details are sharp with no overexposed parts. Did you use a ring light for that image?


Peter

[dougsmit]

Looking good.  Mine was taken before I had a ring and I really don't know which light it used.  Sorry. 

[peterpil19]

Thank you Doug,

I'll make sure to post photos soon of the same coin once I purchase a dSLR.
I am curious to see the difference it will make!

Peter

[peterpil19]

I borrowed a friend's dSLR but it did not come with a macro lens and we did not take any photos decent enough to display here.

I have attached a photo using a completely different lighting set up.

I used direct light from the top of the coin. In between the light and camera on the copy stand I placed a piece of baking paper which I folded back and forth like an accordion so that it could stand vertically with limited support and also do a better job at diffusing light than tissue paper.

I am happy with the result. I am happier with the obverse than the reverse which is worn fairly flat and dull no matter which lighting set up I used.  The DIVA part of the legend is not out of focus - it is just more worn than the rest of the legend.

Peter

[dougsmit]

I am happy with the result. I am happier with the obverse than the reverse which is worn fairly flat and dull no matter which lighting set up I used.  The DIVA part of the legend is not out of focus - it is just more worn than the rest of the legend.

You should be happy.  Keep up the good work.

[Molinari]

I agree.  Nice photo.

[peterpil19]

Thank you both of you for your kind words.

Thank you Doug for your helpful advice.

Peter