What's the point of using an Incident meter?

[david_henderson]

"But, but.... if you take enough spot readings and average them, then isn't that exactly the same as taking a wide area reflectance reading?"

 

No. Not at all. Because you don't average those readings ( well I know some people do but thats not IMO the right way). You actually choose between those readings in the knowledge of how those other areas will be rendered. So no.

[AlanKlein]

Why do reflective readings differ from incident readings by up to a stop?

[Ed_Ingold]

The Sekonic L-508 reads incident light as 13% reflectance. If you use a high quality, matte 18% grey card, a reflectance meter will read about a stop lower. If you don't use a standard card, anything goes.

[rodeo_joe1]

You actually choose between those readings in the knowledge of how those other areas will be rendered. So no.

Hmmm. But if you have enough knowledge/experience to decide which spot reading to use, or which part of the subject to meter, then you can figure out any exposure adjustment from an incident reading. All you need to know is that 100% reflectance (or 'white with texture' in zone parlance) is 2.5 stops more than an 18% reflectance or incident reading.

 

Of course there are a few situations where you can't get into the same light as the subject to take an incident reading, but that's pretty rare.

[david_henderson]

Rodeo Joe. You speak like someone who thinks that I need some sort of reason not to use the methodology you prefer. OK here it is. For the films I used I needed a methodology that told me whether and where parts of my my pictures were likely to render as detail-less black or white. So that I could consider options to avoid those outcomes.

[BeBu Lamar]

The Sekonic L-508 reads incident light as 13% reflectance. If you use a high quality, matte 18% grey card, a reflectance meter will read about a stop lower. If you don't use a standard card, anything goes.

 

It would read about 1/6 stop higher with an 18% gray card.

[Ed_Ingold]

More like 1/2 stop, discounting the extreme flat pigment finish of a $100 grey card.

[Karim Ghantous]

Karim, I'm starting to get into using my digital camera as a light meter as well. I shoot Tmax 100 BW and Velvia 50 chromes mainly. Any tips you can suggest that would help?

The only thing that you probably must do is to compare your film camera's TTL meter with the digital camera's readings. To be sure, don't trust the LCD, look at the file on a computer. I suspect it will be good enough to use with Velvia.

 

OTOH, if your digital camera has zebra stripes (I imagine it would) you could actually use the LCD as a rough proof. In any case, at the worst, you'll have to burn a roll of Velvia to compare it to your camera. Or, just adjust your process as you go without doing a test. Just dive in. :-)

[rodeo_joe1]

Rodeo Joe. You speak like someone who thinks that I need some sort of reason not to use the methodology you prefer.

No. I wasn't directing those comments at you personally David, just putting out an argument against the habitual use of a spotmeter. Because I see a fair few posts that make it appear that use of a spotmeter is indispensable, which IMO is bad advice for many people.

 

Part of the problem is that EVs are logarithmic, and can't be simply averaged.

 

Example: We have a perfectly ordinary scene that gives spotmeter readings of 15.5 EV in the highlights and 8 EV in the darkest parts we want recorded. Only a range of 7.5 EV, and well within the capability of any negative film or digital camera. However, if we naively average those readings we get EV 11.75, which would overexpose our highlights by more than a stop. Whereas the correct reading of 13 EV (same as an incident reading) puts our highlights exactly where we want them, at 2.5 stops above mid-grey, and places our shadows 5 stops under mid-grey, with just visible detail.

 

That's one simple example of how use of a spotmeter can catch out the unwary, and those without a good grasp of sensitometry or awareness of the logarithmic nature of EVs and F-stops.

Edited September 2, 2020 by rodeo_joe|1

[david_henderson]

My slide films could cope with a brightness range of 4 or 5 stops. I found it indispensable to have knowledge of how different parts of the scene would be rendered if I chose any specific exposure level. And I'd systematically check around the frame along the lines of "well at f11/1/60 those trees are going to be 1 stop darker than a mid tone, that path would be a half stop lighter than a mid tone, but the bright parts of the sky are 4 stops lighter than a mid tone so I need either to cut it out or use a 2 stop grad". That, as a quick paraphrase of a process that stood me well through 10+ years of MF slide film with good results, albeit sometimes one concluded that a shot simply wasn't do-able with that film. I found no need or advantage in averaging spot meter readings

 

I started to use FF digital in 2008. Within a year I'd sold the Sekonics and haven't needed to use a spotmeter since. And to be fair I haven't missed the few minutes of palaver before deciding whether I could make a successful photograph before even getting the camera out. But then neither do I miss scanning slide film, and buying & carrying around 100 rolls of film on a longish trip.

[rodeo_joe1]

I found it indispensable to have knowledge of how different parts of the scene would be rendered if I chose any specific exposure level. And I'd systematically check around the frame along the lines of "well at f11/1/60 those trees are going to be 1 stop darker than a mid tone, that path would be a half stop lighter than a mid tone, but the bright parts of the sky are 4 stops lighter than a mid tone so I need either to cut it out or use a 2 stop grad"

Exactly!

And I'd argue that anyone with sufficient knowledge and experience to do all of that doesn't really need a spotmeter, and could equally work out the exposure needed from an incident reading. Because there's only a quite limited range of reflectivity that can usually be encountered. E.g. Fluffy white clouds, snow, whitewashed walls, etc. - all close to having 100% reflectivity; black velvet, shade under foliage - about 1% reflective. That's only a 7 stop range, and anything outside of that, like specular highlights or tarmac in shadow, is pretty much expected to be lacking detail.

 

So we're left with only about two stops of indecision between your picky slide film and likely real world brightness values. Which is going to get preference? The highlights or the shadows? That's not a ponderous choice.... and there's always bracketing.

 

But as you say, most people these days have left that cramped tonal world behind and moved to shooting digital with a decent TTL meter - plus histogram!

[david_henderson]

Bracketing? I did work out once - about 20 years ago- what it would cost me to bracket, given I bought film reasonably efficiently but used a pro-lab to process it. The answer then was about £7 000 pa if I bracketed twice for each shot. And it would have meant carrying c 250-300 rolls of E6 film on a 3 week trip without for the moment fretting about the storage implications and cost unless I threw all but the best exposures away. No thanks. I preferred to put the effort into getting the exposures right and stay solvent.

[Karim Ghantous]

I preferred to put the effort into getting the exposures right and stay solvent.

That should be the default position. With some subjects you don't get a chance to bracket. However, bracketing is insurance. It is - or was - the cost of doing photography.

 

Those who did bracket some of their best compositions will be rewarded by being able to combine those exposures digitally for a semi-HDR image. It's a process that does take time but you can do it.

[rodeo_joe1]

With some subjects you don't get a chance to bracket.

If that's the case; you don't get the chance to fart about with a spotmeter either!

[William Michael]

Bracketing? I did work out once - about 20 years ago- what it would cost me to bracket, given I bought film reasonably efficiently but used a pro-lab to process it. The answer then was about £7 000 pa if I bracketed twice for each shot. And it would have meant carrying c 250-300 rolls of E6 film on a 3 week trip without for the moment fretting about the storage implications and cost unless I threw all but the best exposures away. No thanks. I preferred to put the effort into getting the exposures right and stay solvent.

 

 

Yeah, well, I sincerely appreciate the sentiment, and also the construction of the reply and the message contained in it: but, for the benefit of the OP, I truly do think that the aforementioned reference to “and there’s always bracketing” was meant to mean that one can always choose ‘selective bracketing’, and not that bracketing was fait accompli.

 

WW

[William Michael]

Karim Ghantous said:

With some subjects you don't get a chance to bracket.

 

If that's the case; you don't get the chance to fart about with a spotmeter either!

 

Indeed. well, that's probably stopped that line of debate.

 

WW

[Ed_Ingold]

There was a time when you couldn't throw a penny in a book store without hitting a book on the basics of photography. Aside from the Ansel Adams trilogy and online shopping, I'm hard pressed to see anything of the sort. Even book stores are disappearing along with traditional camera shops. I suspect not many newcomers have been exposed [pun intended] to the use of light meters. Why, indeed, would one use an incident meter? Why, indeed, not provide examples, pro and con? PNET should be a place of discussion and learning, defining goals, not questioning motives.

[Robin Smith]

Re: bracketing no one would ever suggest bracketing every shot with film. That's silly. But there are always shots where the light is difficult to assess, and/or you don't know what exposure result will look the best. Those shots are the ones you bracket, or you can incident meter or spot meter, or do all three. Even then "correct" exposure is not necessarily the one you end up liking the best. For modern digital cameras there is very little point in incident metering as I think we have established.

[AlanKlein]

The Sekonic L-508 reads incident light as 13% reflectance. If you use a high quality, matte 18% grey card, a reflectance meter will read about a stop lower. If you don't use a standard card, anything goes.

So which do you use to set the exposure?

[AlanKlein]

Re: bracketing no one would ever suggest bracketing every shot with film. That's silly. But there are always shots where the light is difficult to assess, and/or you don't know what exposure result will look the best. Those shots are the ones you bracket, or you can incident meter or spot meter, or do all three. Even then "correct" exposure is not necessarily the one you end up liking the best. For modern digital cameras there is very little point in incident metering as I think we have established.

I always bracketed my medium format shots. Landscape. I figure that I spend so much time getting to a shot that I want it to be exposed correctly. Shooting Velvia 50 also makes it more likely that I could be off then when I shoot BW negative film which is more forgiving. Now that I shoot 4x5, I'm shooting only one and missing the exposure more often than I want. Hopefully I;ll get better.

[Ed_Ingold]

For modern digital cameras there is very little point in incident metering as I think we have established

Not established at all. I use incident metering exclusively for large group photos with strobe lights, profiling the stage at various points. Even under continuous lighting, incident readings are the best way to minimize the effects of the set and clothing of the group, and get good exposure for faces. It is especially useful for formal group photos at weddings and events, where clothing is predominantly white or black in various combinations. Incident readings provide consistency, which is good to have when you may have hundreds of images to edit.

[Ed_Ingold]

So which do you use to set the exposure?

I use the setting as given. A half-stop is trivial for digital imaging, or even color negative film. I make 1/4 stop adjustments in post, which are easily visible but largely a waste of time in the field.

[Robin Smith]

Good for you Ed. I don't. I usually take a few test shots and then adjust accordingly using the histogram. Or I will spot meter a face and go from there. Once a setting is correct for the scene for a group shot there is little need to change it. If the lighting is the same then changing the clothes won't make a difference. I retired my Sekonic years ago.

[William Michael]

Weddings and Social Events is a topic area where I can respond based upon experience, having shot just over 1,500 Weddings in my career: I haven't counted the social functions.

 

My college training in Portraiture Photography was using 5x4 monorail cameras, photo-flood lighting, using an incident light meter: and at the same time on the weekends and at any spare time, I was shooting weddings (using 6x6 and 645) for the local studio and sport (135 format) for the local newspapers.

 

'consistency' across a Wedding Shoot / Wedding Album is easily attained by keeping the exposure accurate and (moreover) consistent through each lighting set. Doing so also creates a standard editing starting point for each lighting set: similarly, when we were using film, each lighting set could be addressed and matched as one whole by the printing technician, to keep consistency across the album, even a good consistency across the run of Proof Prints was possible, if the Photographer was skilled enough to keep his/her exposures tight.

 

It might be a cultural or geographic difference, but here, photographing a wedding is similar to photographing some sports: there is somewhat a defined script which can be expected, but the play within that script can, at times, be quite fast and (importantly) you're never likely to get a second shot at 'the moment'. Also similar to a sport's team, a wedding group is there to play, and not to be waiting around for the ref to give instructions or to check the ball's inflation: the wedding group is not there at the beck and call of the photographer whilst s/he manipulates light meter readings and attends to other technical fiddles using an hand held meter.

 

The introduction of TTL Metering meant that wedding photographers could move faster and be prepared more quickly, than when having to use Hand Held Meters: I don't know of any established wedding studio/photographer locally or within our national professional association who uses hand held meters for Group Portraiture, or Bridal Portraiture, be they using Available Light or Speedlites: the one situation where an hand held meter might be used, is for Studio Portraiture when exclusively using Studio Strobes, however, most of the professional studios who still provide this service, here in AUS, tether the camera to a studio monitor and interrogate and refine the lighting and exposure from the test shots using that method.

 

The last time I used an Hand Held Meter was for Studio work, to meter Studio Strobes: forensic photography, recording items for insurance purposes.

 

***

 

It's worthwhile noting that the conversation has digressed: and I think within that context it is worthwhile mentioning that my opinion also is:

 

“. . . the OP's original questions seem to me to indicate that he doesn't understand how spot metering (indeed any reflective metering) works.” - David Henderson’s comment in Post #47.

 

Although the OP has stated that his questions have been answered, I am not convinced that he understands exactly how different metering systems work; what information those meters provide; and what methods and procedures the Photographer should use to correctly apply that information.

 

WW

Edited September 3, 2020 by William Michael

[Ed_Ingold]

In context, I use the incident reading, not from a grey card nor estimating18% reflectance. In any case, I take test shots with digital to make sure faces look about right. Clothing and environment make no difference at all to an incident or spot reading on the face, but reflectance readings, including matrix readings, are strongly affected. Since most of the groups I shoot are wearing all white, all black or a mix, It's something which demands a lot of attention.

 

For whatever reason, large soft boxes tend to overexpose faces. I ultimately underexpose by about a stop to make sure none of the highlights blow.