What did I do wrong? help me with my 1st post

[Dakewl]

Well I want to use my first post to say hello to this great forum which I found via jimmyd's blog

Second I want to show you a shot I made some days ago, and the girl has too much light on here face (in spanish we say that it's burnt, dunno if it's the same in english)

But dont know why, my fotometer said 1/125 f/11 ISO 100, so what did I do wrong? Comments most welcomed. I show you also the lightsetup.

[R_Fredrick_Smith]

The meter didn't give you the correct reading. That is very common. You must calibrate your meter. If you are shooting digital, then after you shoot a shot at what your meter shows, you need to be able to determine at that point whether it is the correct exposure. In this case it wasn't. One easy method, is to use a gray card and shoot it full frame. This will give you one spike on the histogram of the camera. If the spike is in the middle then the exposure is proper. If not, then you adjust the fstop and shoot again until you get the spike in the middle. Whatever the fstop is when you get the spike to the middle, is what your meter should have given you. So the difference the fstop the meter reported and what you've found with the gray card is the compensation you must make in the future.

Here is the kind of target I use. Notice the spikes it produces.

Re: What did I do wrong? help me with my 1st post 

Also your diagram shows one thing, but the photo indicates its not really accurate. For example the background light is not pointed on the background behind the subject but off to the left and it is set to powerful relative to the other lights and is what caused the white area in the upper left.

The shadow is wrong on the nose because the light over on the right is too far to the right. Further, if you shoot the way you show, you're going to get light spilling into the lens of the camera.

Added note: You also must properly use the meter. It needs to be held at the right spot and usually shielded from all but the main light (at least for main reading).

cheers,
Roger

[Stecyk]

Originally Posted by R_Fredrick_Smith

The meter didn't give you the correct reading. That is very common. You must calibrate your meter.

I would like to ask a quick few follow up questions. Are you calibrating the meter, the camera, or both? In other words, if ten different cameras used the same settings, would all yield the same result? Similarly, would ten different light meters give the same 1/125 f/11 ISO 100? I am not sure how tight the tolerances are on either the camera or light meter. I would hope that the tolerances are very close on both.

I understand that through your process the light meter and camera should now work in harmony. But if you were to switch cameras, would you need to recalibrate?

Thank you.

[R_Fredrick_Smith]

Originally Posted by Stecyk

I would like to ask a quick few follow up questions. Are you calibrating the meter, the camera, or both? In other words, if ten different cameras used the same settings, would all yield the same result? Similarly, would ten different light meters give the same 1/125 f/11 ISO 100? I am not sure how tight the tolerances are on either the camera or light meter. I would hope that the tolerances are very close on both.

I understand that through your process the light meter and camera should now work in harmony. But if you were to switch cameras, would you need to recalibrate?

Thank you.

The process I describe would be calibrating the meter. I'm using the word calibrate loosely, however. I'm not assuming that you adjust the meter (although many meters can be adjusted up or down). What I'm trying to determine is the fstop difference between the meter and what the best exposure actually was. The gray card is the constant. The meter was factory calibrated in all likelihood to a gray card.

Unfortunately, 10 different light meters would likely give 10 different readings. I've participated in 100's of workshops where multiple photographers brought light meters. I've seen on almost every occasion a wide variation (1 -2 fstops) between meters.

What I want to know about the meter I use, is how does the reading it gives for the fstop actually compare with the fstop that would be best for properly exposing the photograph.

So, suppose the meter says f8 and I determine using a target that the best fstop is f11. Then in the future for that camera and that general lighting condition, I'll compensate the meter's reading by 1 fstop. I'll still test with my target, but I'll begin the test at the fstop as compensated.

I find that each camera tends to give different results. Fstops should be the same no matter what camera (as far as the amount of light that hits the sensor), but keep in mind that each digital sensor renders what it sees in a different way and the parameters set for contrast, saturation, etc. also affect the results.

So If I change cameras, I use my target to see if I'm getting the same results at the same fstop.

cheers,
Roger

[Stecyk]

Originally Posted by R_Fredrick_Smith

The process I describe would be calibrating the meter. I'm using the word calibrate loosely, however. I'm not assuming that you adjust the meter (although many meters can be adjusted up or down). What I'm trying to determine is the fstop difference between the meter and what the best exposure actually was. The gray card is the constant. The meter was factory calibrated in all likelihood to a gray card.

Unfortunately, 10 different light meters would likely give 10 different readings. I've participated in 100's of workshops where multiple photographers brought light meters. I've seen on almost every occasion a wide variation (1 -2 fstops) between meters.

Your information is helpful to me. I just bought a new Sekonic light meter. In reading through the documentation, I note it does provide for compensation. But the compensation appears to be for mechanical devices.

How to use the Exposure compensation function
Exposure compensation can be made in precise 1/10 step increments in a +/-9.9 EV range. Exposure compensation may be desired when requiring compensation for filters, bellow extensions, etc.

From your information, however, I might want the meter simply compensate for it and my camera working together even under normal conditions so that I get the proper exposure.

Originally Posted by R_Fredrick_Smith

So If I change cameras, I use my target to see if I'm getting the same results at the same fstop.

So the camera too has some play in how it uses the available light.

Thank you for your help.

[Dakewl]

Thanks a lot for your answer it's been very hepful. I'll get one of those grey cards

[jtsmith]

I think it's important to note for determining if your meter is that far off, is to how or where you placed the meter?

JT

[Dakewl]

Originally Posted by jtsmith

I think it's important to note for determining if your meter is that far off, is to how or where you placed the meter?

JT

I placed the fotometer close to the girl's face and towards the softbox

[jtsmith]

Originally Posted by Dakewl

I placed the fotometer close to the girl's face and towards the softbox

...and your camera, lens, and ISO setting were exactly set to the meter read out?

Sorry if you pointed this out in the thread but I just read where your meter read this and just wanted to make sure you had your camera exactly set to that.

J T

[Dakewl]

Originally Posted by jtsmith

...and your camera, lens, and ISO setting were exactly set to the meter read out?

Sorry if you pointed this out in the thread but I just read where your meter read this and just wanted to make sure you had your camera exactly set to that.

J T

Yes, the camera was an EOS 20D with 18-55 lens and ISO100

The rest of the photos went ok, because I just set the camera to f13 instead of what the fotometer said