Light meters and exposures

I need a good light meter and I want a nice one. Can anyone tell me if digital cameras use the same type of light meters as a film camera? I have had consistently bad light readings with my old meter. I get a light meter reading and transfer the settings to my Canon 10 or 20D in manual mode then take the shot. I get underexposed shots every time. I have not been too successful in changing over from film to digital. What is a good light meter? Thanks for any help: Tony

There are no special light-meters for digital cameras. If you use your flash-meter correctly and get wrong readings, that could be only bad flash-meter. Minolta flash-meters are used by professionals and I own their V model. It is very accurate, simple to use device.

del.rio@verizon.net wrote in post #3295193
I need a good light meter and I want a nice one. Can anyone tell me if digital cameras use the same type of light meters as a film camera? I have had consistently bad light readings with my old meter. I get a light meter reading and transfer the settings to my Canon 10 or 20D in manual mode then take the shot. I get underexposed shots every time. I have not been too successful in changing over from film to digital. What is a good light meter? Thanks for any help: Tony

Sekonic
Gussen
I heard even Minolta is great

Now till you get a decent lightmeter try you adjest the settings yourself, try with Av or Tv and see what reading you can get, and i am wondering if your old lightmeter giving you wrong readings all the time so why you keep using that readings then, i do take readings 1 or 2 times then if that readings are all not accurate then i never use it again.

If you're taking readings and your images are consistently underexposed then I would check your settings to make sure they are correct and you don't have any offsets anywhere.

You can check some things with your meter. If you have a white background, take a reflected reading from the background. That reading you get it what the meter thinks will give you 18% gray. Then position a light in front of the background and adjust the power level until you measure 3 full stops above the first reading. That should give you white. Look at that image on your computer and open it in Photoshop or Lightroom and see if that white background not only looks white but the numbers will also display it as well. In Photoshop you should see numbers very close to 255 on the Red, Green and Blue channels. In Lightroom you should see between 95 and 100% on all 3 channels. You can also check exposure with a subject but it might not be as obvious to see if or how much you're off.

See how much your images are underexposed and if that is consistent. If that is the case and you always found the meter to be accurate when working with film then you may just have to establish a working ISO for your digital camera and sensor. For example, if you find that you are consistently underexposed by 1 stop then you may have to use that as an offset to determine proper exposure. If that is the case and you shoot at ISO 100 then set the ISO on your meter to ISO 50 and then take those readings and transfer them to your camera and see if you are getting accurate exposures.

TMR Design wrote in post #3295381
If you're taking readings and your images are consistently underexposed then I would check your settings to make sure they are correct and you don't have any offsets anywhere.

You can check some things with your meter. If you have a white background, take a reflected reading from the background. That reading you get it what the meter thinks will give you 18% gray. Then position a light in front of the background and adjust the power level until you measure 3 full stops above the first reading. That should give you white. Look at that image on your computer and open it in Photoshop or Lightroom and see if that white background not only looks white but the numbers will also display it as well. In Photoshop you should see numbers very close to 255 on the Red, Green and Blue channels. In Lightroom you should see between 95 and 100% on all 3 channels. You can also check exposure with a subject but it might not be as obvious to see if or how much you're off.

See how much your images are underexposed and if that is consistent. If that is the case and you always found the meter to be accurate when working with film then you may just have to establish a working ISO for your digital camera and sensor. For example, if you find that you are consistently underexposed by 1 stop then you may have to use that as an offset to determine proper exposure. If that is the case and you shoot at ISO 100 then set the ISO on your meter to ISO 50 and then take those readings and transfer them to your camera and see if you are getting accurate exposures.

A working ISO sounds like the key. I'll let you know how that works. Thanks very much.

begovics wrote in post #3295274
There are no special light-meters for digital cameras. If you use your flash-meter correctly and get wrong readings, that could be only bad flash-meter. Minolta flash-meters are used by professionals and I own their V model. It is very accurate, simple to use device.

Thank you. That was a concern (digital versus film light meters) that is. Now that I know there's no difference I am going to try Robert's advice and try to get a working ISO. I appreciate the recommendation: Tony

TMR Design wrote in post #3295381
If you're taking readings and your images are consistently underexposed then I would check your settings to make sure they are correct and you don't have any offsets anywhere.

You can check some things with your meter. If you have a white background, take a reflected reading from the background. That reading you get it what the meter thinks will give you 18% gray. Then position a light in front of the background and adjust the power level until you measure 3 full stops above the first reading. That should give you white. Look at that image on your computer and open it in Photoshop or Lightroom and see if that white background not only looks white but the numbers will also display it as well. In Photoshop you should see numbers very close to 255 on the Red, Green and Blue channels. In Lightroom you should see between 95 and 100% on all 3 channels. You can also check exposure with a subject but it might not be as obvious to see if or how much you're off.

See how much your images are underexposed and if that is consistent. If that is the case and you always found the meter to be accurate when working with film then you may just have to establish a working ISO for your digital camera and sensor. For example, if you find that you are consistently underexposed by 1 stop then you may have to use that as an offset to determine proper exposure. If that is the case and you shoot at ISO 100 then set the ISO on your meter to ISO 50 and then take those readings and transfer them to your camera and see if you are getting accurate exposures.

That's what it was. I can't believe it was such an easy task. Thank you for your knowledgable advise. I am up later than I have been in a long time but when I read your reply I had a good feeling so I had to put to work right away. I'm at least two thirds of a stop off. I'll know better after testing it outside tomorrow. I'll also do the white balance test. Thanks again: Tony

i use a sekonic and once I didn't believe it, i had under exposed photos, now I never doubt it.

Hi Tony,

I'm glad that made sense and seems to be the issue. When I had my Sekonic L-358 I found that I had to use a working ISO of +1/3 stop (when shooting at ISO 100 the meter was set to ISO 125) to really lock in correct exposure. Once I figured that out my exposures were spot on every time. Without the offset I was consistently 1/3 stop overexposed. I now use the Sekonic L-758DR with a custom profile for my 30D and I never have to question it.

Every meter and every camera/sensor are different. Light meters measure light over a huge range, whereas camera's like the 30D only have about a 4 1/2 stop dynamic range.

Robert- Can you explain the custom profiling function on your meter? How do you create the profile it and how does it benefit your exposure readings?

RichNY wrote in post #3300786
Robert- Can you explain the custom profiling function on your meter? How do you create the profile it and how does it benefit your exposure readings?

I am interested in this too

Hi Rich and Steve,

Let me say this about Custom Profiles first. For everyone that thinks they need this and it's the be-all answer to better exposures, it's not. What I mean is this. You still have to understand light and exposure and be able to make sense of all the numbers that a meter like the Sekonic throws in front of you. This meter is NOT going to help you make better images if you were unable to do so in the first place.

There are minute differences between cameras, sensors and meters. From what I've seen there can be variations of up to about 1 stop (that is extreme, it seems more common to have variation of + or - 2/3 stop) and it's just not acceptable to be that far off in my opinion. In RAW it might not be terrible and you could probably recover shadows or highlights lost but you have to remember that the big deal over custom profiles is directed towards those that shoot JPG and at higher ISO. I know the RAW vs. JPG issue is much debated so let's not do it here, but many pro's and amateurs alike choose to shoot JPG. With JPG you have much less latitude in terms of exposure and I love the expression that Will Crockett uses with respect to a JPG that is 2/3 overexposed.. "Pixel Fatality". It's a great term.

Having said that, here's the deal on custom profiles. If you're shooting JPG and the workflow has to be spot on exposures that need little to no post and right to print then you are going to benefit the most from using custom profiles. For everyone else, the most useful thing about the custom profile is that is shows you where you do and don't have room to push your exposure and where you're going to to get into clipping. So rather than 'rounding up' and perhaps overexposing or going into clipping it will give you the safer number and keep you within safe limits. The profile shows the dynamic range of your camera's sensor at different ISO's. That is extremely useful. An example of that is how I, like many people would shoot at ISO 100 because it supposedly has the least amount of noise and greatest dynamic range. Well, not on my 30D so I no longer shoot at ISO 100. I confirmed what I had read in an article somewhere on this subject, which is that the greatest dynamic range with the least noise, based on keeping you out of clipping is at ISO 125 or ISO 160 and not the native ISO 100 and ISO 200 that most would use.

What does this mean? It means that at ISO 100 I have a dynamic range of 4.2 stops and at ISO 125 I have a 5 stop dynamic range. It means that at ISO 100 I'll go into clipping if I'm off by -.8 stop or (get this) +.5 stop. So if I'm overexposed by 1/2 stop I'm already in clipping. At ISO 125 I have a .8 stop greater dynamic range and I have the latitude to be over or underexposed by 1 full stop without going into clipping. That's enough of a difference to make me want to use ISO 125 even without using a profile and I recommend making that switch for anyone using a 30D.

I would imagine that you would see the dynamic range improve if you went from 30D to 5D and again to 1Danything.

OK to put it all into perspective...honestly​, if I never had the ability to do custom profiles and the feature wasn't even an option I would never know, care or miss it. As a geek I love having the information it provides and like knowing it will 'keep me safe' as it were, but my exposures were fine with the L-358. Is it cool? Absolutely. Do you really need it? No. If you have an L-758DR and are not using custom profiles are you missing out on some big amazing feaure? Nahh.
When I got the L-758DR I got it for 2 key reasons, neither of which was custom profiles. I got it for the built in Pocket Wizard transmitter module and the built in 1 degree spot metering.

If others have the meter and a 30D but don't want to buy the calibration target you can input the numbers manually from another profile or you can use someone elses profile to transfer it from your computer to the meter and it would work fine. The difference between camera models would be significant but from one 30D to another would be minute, if any.

So if you want to check out a 30D profile, here you go. It covers ISO range of 100 to 1600 for Flash/Incident. Since I can't upload a .csv or .xls file I can't actually post a complete working profile so this is just a PDF. If you want the actual profile just PM me with your email address and I'll send it to you.

also the 758 (dont know about the 358) has a global exposure compensation setting, so you can use the same iso on the meter and the camera.

Many thanks Robert, thats very interesting about the iso125 having more dynamic range on the 30D. Would you happen to have any info on the 5D?

Many thanks

Hi Steve,

If I had a 5D at my disposal I would set up the calibration target and just do a few ISO's to get an idea.

I would be very curious to test another camera..any camera. I suspect that the 5D would have a wider dynamic range than my 30D, and I think that also has a lot to do with the way the 5D images really pop and have great depth and contrast. I'm going to convince my friend to leave me her Nikon D-70 so I can test it and compare.