Coin Photography - Lighting?

[TheGoldSovereign]

So I'm playing around with lighting on a lower grade coin to see what works across the board, I can't afford to setup lighting different for each coin, far too much time required for that!

The images below have no post-processing at all, not even base curve has been applied so they are completely RAW and I'm aware not pleasing to look at. However, this is the part of the issue I'm finding, with this angle I can't seem to get every part of the coin well lit without it getting washed out and showing up too many flaws.

Please pic a favourite using the poll!

Image 1

Image 2

Image 3

Image 4

Image 5

Image 6

[augur]

Image 6 for left facing, image 1 for right facing portrait 

image 3 is more universal but the exposure values need a bit more tweaking. 

 

You also would have to find s compromise that deals well with shiny and dull coins. 

[sixgun]

It is either image 1 or 6. i could go either way - as it was i voted for image 1. The light illuminates the face as if it were a light shining toward the face so giving a 'natural' lighting to the subject. So light may be different depending on the subject and its orientation on the coin face. i chose 1 as there is a lot of detail in Victoria's hair at the back and the lighting in 1 shows this off a little better. A subject with less detail in the back of the head would favour the lighting in image 6.

[TheGoldSovereign]

I can't find my damn tripod adaptor so I'm unable to get a good example of what I'm trying to explain, I've attached the best I can get handheld.

As you can see the coin is much "smoother", it looks like a completely different coin, any ideas why i can't replicate this at 90degrees? The fact is a lot of these coins look very nice to the eye, and that's what I'm trying to capture. This method of lighting is forcing the flaws to which the eye can't even see.

[augur]

The flatter the light, the more shadows and highlights you will get over the coin surface of a circulation coin. Even on a proof coin you will get increased glare. 

If you have light from the direction of the lens via a semitransparent mirror, this will be less of an issue (unfortunately i think your new USB camera will not be best suited for this). 

From my experiments it is also a good idea to avoid any scattering light by placing the coin inside a dark tube. By slightly accentuating the face, you can then personalise the light to the respective obverse. 

[TheGoldSovereign]

6 minutes ago, augur said:

The flatter the light, the more shadows and highlights you will get over the coin surface of a circulation coin. Even on a proof coin you will get increased glare. 

If you have light from the direction of the lens via a semitransparent mirror, this will be less of an issue (unfortunately i think your new USB camera will not be best suited for this). 

From my experiments it is also a good idea to avoid any scattering light by placing the coin inside a dark tube. By slightly accentuating the face, you can then personalise the light to the respective obverse. 

So firstly this is using a DSLR, the same body and lens you've seen all my pictures taken with. Secondly I am pointing the light straight down from above the lens as you point out, these images are with the lights at different heights and intensities.

This is why I can't understand how I'm unable to replicate the lighting in the above picture, which is daylight. But these are daylight LED lights and I can change the colour also slightly.

 

[TheGoldSovereign]

This is the best I can get right now, with little time. It's possible to create dawn masks over the date and legends and improve those areas individually, but that's far too much work to be honest

[TheGoldSovereign]

@augur Playing with angle some more, and I think i prefer the aesthetics of this one and might be onto a winner?

This has the high beam but also another coming in from about 45deg. This is JPG straight from camera.

Amazing how the same coin can look so different eh! and this is why I don't buy "graded coins" based on photos

 

[sovereignsteve]

Yes I've found you need some light coming in from the side at whatever angle gives the best result. I've also found it's better not to have the lens directly above and at 90 degrees to the coin.
Your last examples would be fine for archiving and I would be happy to have those to look at when buying.

[TheGoldSovereign]

12 minutes ago, sovereignsteve said:

Yes I've found you need some light coming in from the side at whatever angle gives the best result. I've also found it's better not to have the lens directly above and at 90 degrees to the coin.
Your last examples would be fine for archiving and I would be happy to have those to look at when buying.

Yea this light from the side is a game changer , though i can't change the lens angle as that is kind of the point of the copy stand setup.

Pretty happy with the last results so I can move forward from there now and actually get some images archived

[augur]

Looking good! Exposure looks good, too. 

If you have a post processing program that can lift the shadows and blacks for a more even exposure of the coin...

Once you found the right settings you can batch process all your coin images - again you should find settings that would work for the extremes so that you can work away. 

You can always tweak the images you want to publish 

[sovereignsteve]

1 hour ago, sg86 said:

though i can't change the lens angle as that is kind of the point of the copy stand setup.

yes I use one too but you can put the coin slightly to the side and angle the camera on the screw fitting. You can't do this too much or you get some distortion. Also slight difference in focussing range so need a larger f number.

[TheGoldSovereign]

1 minute ago, sovereignsteve said:

yes I use one too but you can put the coin slightly to the side and angle the camera on the screw fitting. You can't do this too much or you get some distortion. Also slight difference in focussing range so need a larger f number.

Yea with you, i'll experiment with that but I think the angle will annoy me in the photos, because for the purpose i'm using it for they ideally should be perfectly flat.

I'm getting better results with f5.6 at the moment actually anyway which would absorb that slight tilt

[TheGoldSovereign]

Very difficult to get the white balance right across multiple photos, I'm sure there is some metering wizardry that can be done here so more research needed.

@augur Can't apply styles across the board it seems unless the lighting, white balance and everything else is exactly the same. It'll take years to adjust each image!

I've just done 3 coins to see how similar i could get them, can't wait to try them out on the website (which is working now but not live)

Also having to resize them to 1600px to get the PNG from 35mb to 5mb  

 

 

 

 

[augur]

To achieve more consistent results you should check the EXIF data of these images and then use manual settings for White Balance, Aperture and Exposure Time. Excluding external light, e.g. working in the evening hours will give you a more consistent colour temperature. 

Also check the histograms to see if parts are overexposed, in particular on shiny coins. In that case you should take at least another image with a shorter exposure time to be able to later create a combined picture (HDR - High Dynamic Range); repeat the exposure with shorter times until there are no more peaks on the extreme right end.

[TheGoldSovereign]

@augur Yea more work to do here, I need to create a better environment but need to wait for this a little longer.

So the HDR suggestion and similar doesn't really work for me, I could bracket shots and then use some expensive/complex software to merge the RAWs but this is usually left down to the camera and its JPGs. For example mind has HDR mode, it'll take 5 shots at different exposures and merge them, i've got awful results with this. Sony's "DRO" method seems much better but again you're stuck with a JPG, and although I'm still only just achieving JPGs with the same quality as the camera, I do think eventually I'll be able to get them better.

All i want to do here is achieve what I can with a stand and daylight at an angle to the coin, still not able to get the lighting right to do that, Think i need some more/different lights.

What do you think on the image below, it's "washed out" and I couldn't bring it back, any idea what to try? (just for learning here)

[augur]

2 hours ago, sg86 said:

What do you think on the image below, it's "washed out" and I couldn't bring it back, any idea what to try? (just for learning here)

Looks completely overprocessed or one of the extreme HDRs that are so on vogue now...

If this is a JPEG, there is no bringing back unless you did use a lossless editing software. 

[TheGoldSovereign]

Na it's RAW, I tried a lot of things to make it look good but couldn't

Back to the drawing board then. Is this something you do? I'd be interested in seeing what you or someone else with good knowledge could do with the same RAW file..

[TheGoldSovereign]

I think this looks better, seems it's better to push the exposure up a stop and go from there

 

[TheGoldSovereign]

@augur May as well keep this lighting stuff here. I've played with angles on the copy stand a little as per @sovereignsteve's suggestion. You can see it isn't in great focus so that part needs more work, but I think the colour and field is much nicer, do you agree?

When you look at 100s of different images and do this post-processing it gets hard to differentiate from one to the other

note: I found center-weighted exposure metering works really well, especially when you have an illuminated back panel like i do here, then it only averages the light from the center 30-35%

 

 

[augur]

Looking better every day. I'll order a lightbox to see if that allows the luster to appear and the scratches to vanish – more like what the coin looks in hand. Still need the semitransparent mirror as the reflection of the mobile phone / lens becomes apparent:

reflection is dark area lower central and lower right area

Also this lens wouldn't cover a sovereign as the half sovereign already almost fills the frame and depth of field is an issue with upper left area slightly out of focus and overexposed...

[shawy2510]

[mention=3678]augur[/mention] May as well keep this lighting stuff here. I've played with angles on the copy stand a little as per [mention=413]sovereignsteve[/mention]'s suggestion. You can see it isn't in great focus so that part needs more work, but I think the colour and field is much nicer, do you agree?
When you look at 100s of different images and do this post-processing it gets hard to differentiate from one to the other [emoji3]
note: I found center-weighted exposure metering works really well, especially when you have an illuminated back panel like i do here, then it only averages the light from the center 30-35%
 

 

Got to say that pictures looks fantastic

[augur]

On 01/06/2018 at 13:16, sg86 said:

note: I found center-weighted exposure metering works really well, especially when you have an illuminated back panel like i do here, then it only averages the light from the center 30-35%

 

 

 I had a look on a computer screen, as usually I access the forum from my mobile: your images are usually a bit underexposed. Spot or centre-weighed metering should give you better results but you could still put in at least another 1/3 or 1/2 stop exposure compensation (slight overexposure) and then pull the highlights down and raid a bit more the shadows and blacks. I am not sure if you eventually see some standard exposure value that works generally and can apply a custom exposure curve so that the post processing is then down to fine tuning for very few coins, that expose differently. 

[dancavendish]

You need one of ring lights for macro pictures.

https://www.fastforwardtime.co.uk/aputure-hc100-on-camera-led-ring-video-light

This is original by canon for about £400.00, but you can by something like this

https://www.fastforwardtime.co.uk/aputure-hc100-on-camera-led-ring-video-light

Probably is not as good as canon but cost only £35.00

Just remember to choose with light option not just flush.

On light is much easier to set up camera.

 

 

 

[TheGoldSovereign]

14 hours ago, augur said:

 I had a look on a computer screen, as usually I access the forum from my mobile: your images are usually a bit underexposed. Spot or centre-weighed metering should give you better results but you could still put in at least another 1/3 or 1/2 stop exposure compensation (slight overexposure) and then pull the highlights down and raid a bit more the shadows and blacks. I am not sure if you eventually see some standard exposure value that works generally and can apply a custom exposure curve so that the post processing is then down to fine tuning for very few coins, that expose differently. 

I'm trying to decide if it's better to whack up the lighting levels, then increase shutter speed. But generally I use auto ISO and set the shutter to keep ISO as close to 100 as possible. So i don't see how they can be underexposed with this method? Should i lower the lighting and leave shutter open for longer instead? My view was faster shutter will always result in a sharper image so went for the first option