Firstly, thankyou for taking the time to do this for the education of all the readers.
Your butterfly setup has the light nicely placed for the face, but I wonder why you shot this from the side only. Surely if making a proof, you'd shoot it from various angles, including the logical place for a butterfly setup; on-axis. You metered towards the light. Had you placed the camera in the logical place for that setup, you'd be using the meter-to-light reading for your camera and it wouldn't be underexposed. How can the same light in the same place and the subject in the same place suddenly be underexposed just because you moved the camera? That doesn't make any kind of sense, let alone a proof. Perhaps you're saying that when you move the camera around to the side of the subject on a butterfly setup, you have to overexpose the face to get a brighter side profile? I don't understand why you'd suddenly want to overexpose the subject just because you've moved the camera 45 degrees off axis. Not sure you've made any point other than to overexpose the face for a butterfly setup if you're off-axis.
In your article, you state:
But this mannequin consists of complex shapes and the light reflects off at all sorts of different angles, which is the main reason , apart from shadows, why the tone always varies across the image, and the main reason why only a meter reading towards the camera position can take any account of these varying angles.
I accept that different angles will reflect light towards the camera differently. That much is simple physics being applied. I wonder, however, how the meter is seeing this reflected light? You're pointing it at the camera, aren't you? So, how does the cone on the meter see that light? If the meter is pointed towards the camera, it isn't seeing that light as the body of the meter is between the subject and the cone.
I just don't see that.
Another quote:
Some subjects absorb far more light than they reflect, and with this type of subject it doesnt always make a big difference whether we meter to the camera or to the light
Which means, quite logically, that with some subjects it really DOES matter which direction you meter in. So some subjects you HAVE to meter towards the light.
You are not proving your point with that statement.
I once had to photography a stainless steel machine with a truly mirror finish, and it was a complete nightmare to get both the light and camera angles right because, except at the perfect angle, all of the light just bounced away into the ether and it was impossible to show it as anything other than black! Metering to the camera was a dramatic demonstration of the importance of correct metering, because there were 8 stops of difference between metering to camera and metering to the key light.
You have no setup shots of that in your article. No finished image displayed. It shouldn't be be in the article as it isn't proving anything, it's just re-stating your position. Saying something is so doesn't make it so, no matter how many times you say it. Only proof makes it so. And this isn't a proof, it's just saying so.
Ive lit it from the side and of course most of the light has just shot off in the opposite direction. Taking a meter reading from the reflector centre to the light indicated f/22, which as you can see is hopelessly wrong. Metering to the camera instead indicated f/11, which is correct.
The time one is shooting a reflective surface, one has highlights and not a fully lit surface. One shoots for highlighting the shapes, the curves, the edges. This is what gives us the 3d lie in our 2d medium. In the same way that we shoot for shadows on non-reflective surfaces, we shoot to highlight shapes, curves and edges.
Your initial shot of the reflector has highlights. This is the correct image, not the second one which is fully illuminated.
Again, point not proven, in fact you've disproved by what you've shown.
For one set of circumstances but not all, is this the exception that proves the rule???? .One thing that has been lacking in this thread by some has been tact. Unfortunately or possibly fortunately none of my clients have a white polystyrene head or at least none have a head with the reflective properties of white polystyrene.And the majority of portraits are shot this way? I think not - the metering has to be relevant to the lighting pattern, no more, no less.
Mike
No. My example early in the thread proves that this unusual lighting setup for a portrait is exactly what DISPROVES the rule being posited by others in this discussion.
I'm just about to hit the land of nodd , but felt compelled to reply, I haven't yet read garrys blog post(need to be fully awake and thinking logically) but mike metering should just be metering the light, not donthis for that light pattern and something else for another, that just doesn't seem right to me
I'm glad someone is seeing why I think it is silly to meter one way for one setup and not for another one.
Very well explained Garry and point made I think
Sorry. Point re-stated, rather than made.
It looks very under exposed. Not just dark, as was obviously intentional, but under exposed.
You would have got a much better result by exposing properly (it's actually a perfect candidate for ETTR) and darkening it in post.
Nope. Just dark. And exposed exactly as my meter told me. Why would anyone choose to deliberately expose incorrectly to then have to fix that in post by doing the ETTR thing? If I did that on a nursery shoot, I'd have perhaps over a thousand images to fix in post-production. No thanks. Just daft. Get the exposure right when you shoot, not deliberately make it wrong to then fix.
A very interesting blog and Garry's demonstration clearly gives the answer, which is the way I have always understood to be correct.
Perhaps not surprising then, that the Sekonic instruction manual states that ..... 'Measurements are basically made by the method of measuring with the lumisphere aimed in the camera direction (more precisely, in the direction of the light axis of the lens) at the position of the subject'
As well respected manufacturers, they would know how best to use the equipment.
Thanks to all for a great read.
Garrys demonstration re-states his position. It doesn't make the point. Please have a read through what I've posted above in response to the article and run the experiments for yourself. When you run them, take shots from multiple angles which will prove things properly and not just the one which supports the position stated.
I've looked at the manuals on the sekonic website for the 358 and 308 and both have your statement in them. I will, however, repeat that if you're using the meter to get your split-lighting correct, that just doesn't work. It also doesn't go into anything past "basically". So unless you want to use the meter for only basic things and don't want to progress, keep pointing it at the camera.
I'm glad that's sorted then.
I wasn't trying to score any points, I was just trying to explain how the fundamental principle works, which is what I feel forums are actually all about. Maybe I should have gone into more detail right at the beginning and saved a lot of 'ink'
I'm not trying to score any points either, and I will repeat my opening of this post. Thankyou for taking the time to do this. We all want correct information to be on the fora and a good discussion such as this will educate some folks in things which will have previously been beyond their experience and I hope it will encourage them to experiment on their own instead of just taking things at face value
Please address the points raised though. Especially how the beauty light shot is suddenly underexposed just by moving the camera off-axis when the light remains the same, the subject remains the same and the only thing which changes is the camera position to 45 degrees off axis.
Never mess with the G-man
lol
Ummm. This is relevant to the discussion how?