Asker Avatar
Anonymous asked:
Zack, I'm going to ask you the single most controversial question in photography. Seriously - I've seen people get REALLY wound up on this issue. When using an incident meter, do you point the dome at the camera or the light source? (I point it at my key light and it's usually dead-on balls accurate.)

All right. Light meters. Do you need them or not in the digital age? Let’s have a discussion about meters, calibrating your cameras and lenses, and really nailing exposure.

I’ve often said that we don’t need no stinkin’ meters in digital. We have our screens on the back of our cameras, histograms, etc. But I always add a caveat. You don’t HAVE to have one. But they are useful. I own a few and use them regularly. The thing is, a good light meter will be somewhere around $300. When you are just getting started, that $300 is sometimes better served elsewhere. Eventually though, you’ll find a light meter on your wish list and you’ll most likely pick one up. An argument could be made that you should get one at the start. I could argue for that. I could argue against it. 

Just never get caught up in the “You never need a meter” or the “You always need a meter” camp. Some think you’re stupid for using one in the digital age. Some think you’re stupid for not using one in the digital age. I ride the fence and say that anyone who plants themselves in either of those two camps is stupid. Then everyone in each of those camps says I’m stupid. We’re all stupid. Ok? 

The reasons meters are important is they give you consistency in your exposures when you use them correctly. The more consistent you are as a photographer at the time of exposure the better your life will be in post production. If you are an inconsistent photographer at exposure then your post production life is going to be a living hell.

I use meters in the “incidence” mode 99% of the time. There’s basically two types of metering modes. Reflective and incidence. The light meter in your camera is a reflective meter. Spot meters are reflective meters. They are measuring the light reflecting off of a subject. Now then, your reflective light meter, spot meter, and in-camera meter doesn’t know what you are photographing. You can read the light reflecting off of something white or off of something black. It doesn’t see that what it is reading is white, or black, or grey, or red, or blue, etc. Since it doesn’t know the value of what it is reading there has to be a consistent measurement to bring that light meter reading to. That measurement is 18% grey. I don’t know why. It just is. Smarter people than me (I?) came up with that.

So you read light reflecting off something white and it’s going to give you a reading to make that 18% grey. Read the light off of something black and it’s going to give you a reading to make that 18% grey. White isn’t grey. Black isn’t grey. So you have to make a judgement call. “I’m getting 5.6 at 250th of a second off of the bride’s white dress. The dress isn’t grey. If I shoot this at 5.6 at 250th then the dress will be underexposed to grey. Therefore I need to open my exposure by X amount of stops to make the white dress white.”

Incident meters (that little white dome on the light meter) is reading the light falling on the subject regardless of whether the subject is white, black, green, grey, blue, dog, etc. You walk over to the subject, put the meter where the light is falling on it, take a reading. It says 5.6 at 60th of a second or whatever. You set your camera to 5.6 at 60th and boom! Balls on accurate. You don’t have to think about it.

Well… You don’t have to think about it ONCE you calibrate it. ISO 100 is not a dead on accurate thing across the board. ISO 100 on a Canon is different than ISO 100 on a Nikon and it’s different than ISO 100 on a Fuji. Camera manufactures play a bit with these numbers. There’s also a bit of room for your personal subjective tastes. Some like to expose just a little darker. Some like to expose just a little lighter. 

So here is what you do. Get ready. Effing boring ass technical talk. Since ISO settings across the board of manufacturers isn’t all that consistent you have to calibrate your meter. I found a full stop difference between my Canon and Nikon cameras. You may also find that ISO 100 on a Canon 7d may be a bit different than ISO 100 on a Canon 5d2. There isn’t much change within one manufacturer but you find a big swing from one company to another usually. To add another odd piece to this puzzle you’ll find that f4 on one lens can be off from f4 on another lens you own. The ISO (International Standards Organization) allows manufacturers 1/3 of a stop wiggle room on apertures in the manufacturing process. So I hear at least.

I’ve found this to be true though in real world applications. I have a Canon 24-70 2.8 lens that is about 1/2 to 2/3’s of a stop brighter than my Canon 70-200 2.8 at any aperture. That means if I shoot something at 5.6 @ 250th of a second at ISO 100 on the 24-70 and then shoot the same exact subject in the same exact light at the same exact settings with the 70-200 lens the resulting photo will be 1/2 to 2/3’s darker than when shot with the 24-70. It happens throughout the aperture range on each lens.

I’ve found that it seems my 70-200 2.8 is the most off from all of my other lenses. They all differ a little from each other but the 70-200 is the most off from a standard base line. So what does this mean?

If you’re really going to dial in consistency in your photography then you want to test your gear and you’ll want to calibrate your light meter to some sort of base line. I typically calibrate my meter to my most used camera and my most used lens. Here’s how I calibrate.

I set up an evenly lit shot. I take a meter reading with my handheld light meter. Let’s say it says f4 at 250th of a second at ISO 400. That’s what the light meter says. I’ll then shoot a bracket of images from one stop under that to one stop over that at 1/3 stop increments. I don’t shoot these at the most open aperture. You can get aperture vignetting at your maximum aperture that makes the exposure look darker. I’ll typically do this callibration process at a middle aperture like f4 or 5.6 or 8 or something. If it’s a 2.8 lens then I’ll do this around 5.6. An f1.8 or so lens I’ll do this around f4 or so.

I take the card out of my camera, pull the images into Lightroom with no adjustments made, and look at the images on a calibrated monitor. I then choose the exposure that I would most like to be the starting point for my post production. Let’s just say that I choose the exposure that is 2/3rds brighter than what my light meter said. 

I then walk around in different light (full sun, open shade, deep shade, tungsten, whatever, etc) and take photos at 2/3rds more exposure than whatever the light meter says to shoot in that light. I go back to Lightroom and see how consistent that is. If I find I’m hitting the consistency that I want then I go into the menu system on the meter and set it to +2/3. That way when I take a reading at ISO 200 at f 2 and it spits out a shutter speed I don’t have to do any further math in my head. I set to that shutter and I’m good to go.

I do the same tests with flash as well. Just to make sure. Then I test my lenses. Then I test other cameras. I make notes and remember that this camera is one stop under from the meter. This camera is one stop over from the meter or whatever. All the calibration is done with my MAIN camera and my MAIN lens. Then notes are made where other cameras or lenses fall from that base line. I once had an old 20mm Nikon lens that had +.5 scratched into the lens barrel. The photographer who once owned that tested their lenses and made notes. It’s been around since film y’all. 

Let’s say I calibrate my meter to my Canon. Then I find that my Fuji’s are 2/3rds of a stop under from that. Where I would set my meter to, let’s say, ISO 200 for the Canon if I’m shooting ISO 200 on the Fujis then I set the ISO on the meter to ISO 125. This is 2/3rds under ISO 200. I take a reading. Whatever that says I set my Fuji to that. I don’t have to look at the reading and then subtract 2/3rds from it. I want to look at my meter, dial that in, and go. I want to keep math out of my head as much as possible.

To the original question. Do you point the white dome at the camera or at the main light. Imagine having your camera on a tripod. Your subject is sitting on a stool directly in front of your camera. Your main light (sun or flash) is 45 degrees to the right of camera. You walk up to your subject and take a reading. Are you pointing the white dome to the camera or the light? This has caused PC vs. Mac types of debates for years. The best answer is to pick one and ALWAYS do that. I think I started out pointing to the camera. Then I got into more dramatic lighting and that wasn’t the best for me so I began pointing the meter at the main light and that is what I always do now. 

Another place the light meter is really helpful is when you are doing a multi day job and you can’t leave your lights set up between shooting days. I just did a job for the Coca-Cola company that required shooting over two days. I had to setup, tear down, setup, and tear down over these two days. Another day might be added to the job for more of these portraits. It was a three light set up and all the portraits had to be consistently lit. Once I was dialed in on day one I took meter readings and made notes so that I could get my lights EXACTLY back to where they were again. This is NOT something you want to do while chimping on your camera. You need to know that you are exactly back to where you were before. 

Oh…. another note about this calibration thing. When you finally get your meter calibrated to where you want it do this. When you have the images pulled up on your CALIBRATED monitor with zero adjustments made to them, put that memory card back in your camera and pull up an image on your monitor and on the back of your camera. Take a look at how that image is produced on the back of your camera. Does it look darker than the image on the monitor? Lighter? You can adjust your screen brightness a bit to try to match them but make more of a mental note. On my Nikon D3 the screen was really off from what I’d see when I pulled the image into Lightroom. If the picture looked PERFECT on the D3 then it was going to be too dark once I pulled it into LR. If it looked just a bit too bright without highlights clipping then it was going to be just right in LR. Make little notes of that so that when you chimp you can translate what you are seeing on your camera to how you expect it to look when you start editing.

I highly recommend getting a meter that reads ambient light as well as flash. Don’t mess around with just getting a meter for ambient only. There are a handful of meters out there. People are about to flood me with, “Well what about this one?” Here’s my list and I’m sticking with it. Based on price range and personal experience.

$168 Polaris - I had this meter when I was in school. It’s a good meter on a budget. The least expensive that I recommend to people.

$233 Sekonic L-308S - GREAT meter at a great price. Has a few more things under the hood than the Polaris. Sekonic makes the best meters hands down. 

$309 Sekonic L-358 - The nice thing about this meter is you can add a Pocket Wizard transmitter to it later for an additional $63. 

$469 Sekonic L-478DR - Touch screen awesomeness. Great UI. Pocket Wizard control technology built in. Not only can you fire your PW lights from this but you can control the power of them if you are using their control technology stuffs. You can set custom profiles and calibrations. Kick ass meter. Just got one of these.

$634 Sekonic L-758DR - If you’re one of those jerks who just has to have the best of the best then get this meter. It has it all except PW control. It has a transmitter but you can’t control power settings from the meter like you can with the 478. Note that you can’t control power via any sort of old PW. I’m not highly versed on all of that. Check their site for the details on that.

I’m only touching on some of what a good meter can do. You can take several readings to find an average in a scene. You can figure out the ratio of ambient vs. flash in a mixed situation. You can add filter compensation into the mix. There’s a lot you can do with a meter beyond finding what shutter speed you should use at ISO 800 at f2.8.

Is all of this overwhelming? Does it all sound like it’s too much of a pain in the ass? Get over it. It’s called professional photography. Be good at your craft. Be great at your craft. Think a pastry chef trusts a new oven to be exactly 350 degrees when they set that on the dial? No. They test it. 350 on the dial might mean 380 degrees in the oven. You need to know that. You need to know your cameras. Your lenses. Your lights. Your exposure. Your screens and monitors. You need to test this shit. It’s boring and tedious and all of that. I know. It is. Get over it. Wait till you build color profiles for all your cameras, lights, and modifiers. Be a professional and do it. Don’t be another mediocre photographer. There’s millions of those. Don’t be one. Be great at what you do. Know what you are doing. Do the hard work to learn all this stuff. It’s worth it. It’ll save your ass one day.


For more info on light meters youtube “how to use a light meter” and go through some of those. I was going to make a video but I’m busy today… ain’t nobody got time for that! :) 

46 Notes

  1. jonathanmrobson said: Fantastic article, thanks for taking the time Zack!