Questions- Need help!

[AlexisG]

Hello everyone.
I took this shot around twelve this morning. He was the only subject I had .

Some concerns I am having:

-If I shoot at the aperature my meter indicates everything looks too bright.

test-2.jpg

[AlexisG]

-If I close down one stop I get this

test1.jpg

Which I think looks underexposed.

[AlexisG]

I have no idea what that gray spot by his ear is...My lens is clean and it won't go away.

What am I doing wrong with my exposure?
Do the images look sharp? I have really bad eyesight and I use auto focus on the camera but lately it's been letting me down. Could it be the lens or me?

[aam1234]

What do you mean by "close down". Also, are using a flash (I'm guessing, yes). I'm also guessing that you are using manual exposure.

Please give more info about your setting.

Btw, from the look of it, the spot seems to be a dirt on your sensor. Were you shooting at f8+

[dc2]

The 2nd is not really under exposed but lacks a little contrast .
A quick levels adjustment will fix it .

[AlexisG]

I am using one 300 watt light with a 24x34 softbox about 3 feet away from the subject. The first shot was shot at f8/125 and the second one was shot at f11/ 125.

[aam1234]

So my guesses were right

I think you will get better responses in the Lighting section of this forum.

Btw, I think the second pic looks way better, exposure wise, than the first. You might want to look at them on a different monitor.

[JohnC]

The gray spot is dust on your camera's sensor.

Are you using a continuous light or flash?

Are you using an in-camera meter or a hand-held meter?

[JohnC]

If f/8 is too bright and f/11 is too dark, what happens if you set an aperture between 8 and 11? Try just closing down 1/2 stop.

[AlexisG]

Originally Posted by JohnC

The gray spot is dust on your camera's sensor.

Are you using a continuous light or flash?

Are you using an in-camera meter or a hand-held meter?

I am using a 300 watt flash and a polaris hand held meter.

[JohnC]

That was my confusion. Flashes are rated in watt-seconds or joules (the charge stored in the capacitor). Watts usually refers to the power of continuous light.

You may need to calibrate the meter to your camera/sensor.

[AlexisG]

I wasn't aware that you had to calibrate the meter to the camera.
Thank you, JohnC.

[JohnC]

The thing is to do some controlled tests. You may find out that when you have the camera set to ISO 100 you have to set the meter to ISO 125 or 80 to get the exposure that you want. Some meters have a dial or electronic control to adjust/calibrate. But with others you just have to keep in mind that you need to adjust a 1/2 stop or whatever from what the meter says.

[Benji]

Here is how I calibrated my hand held meter so when I set it at ISO 100 my camera's sensor will record the image properly at ISO 100. I got an 18% grey card and placed it on a chair facing the light (a flash unit.) For calibrating a meter used for ambient light you do the same. I set the camera on manual and I also both the hand held meter AND the camera to ISO 100 and took an accurate meter reading at the card. I set the shutter speed at 100 (In flash photography the shutter speed is inconsequential unless there is lots of ambient light) then I set the aperture at whatever the hand held meter reading was. I made an exposure of the card ONLY. Fill the frame so only the card is in the image. You may need to "fool" the autofocus or disable it. I made my first of several notations of the aperture. Then I made four more exposures, two in 1/3rd increments more and two at 1/3rd increments less than the original reading making notations as to the number of the image and the aperture reading used for that image. NOTHING else was changed. I then loaded the images into my computer and Photoshop. In Photoshop I went to "Window" and in the drop down menu I clicked on "Histogram." When you bring up each image there will be only one spike. The image that has the spike dead center is the only image that was correctly exposed. Note which image it was and confer with your notes. If it was the very first image your hand held meter is set perfectly. If it was one of the other four images you must do one of two things. If your meter has a small dial (usually inside the battery compartment) you can take a tiny screwdriver and rotate the screw a little to adjust the meter to match the correct reading. This will allow the LCD reading on the face of the meter to read ISO 100. If your meter does not have that dial you will need to increase or decrease the ISO either 1/3rd or 2/3rds (+ or -) to get the correct reading. The ISO on the face of your hand held meter will now read 80, 64, or 125, 160, but the camera will stay at ISO 100. If you have a second meter that you use outdoors you will need to calibrate it the same way.

Benji

[kgphoto]

Benji,

My understanding is that, depending on the camera, center of the histogram is not 18% gray.

Lee Varis published a method in his book Skin and in a Magazine article referenced somewhere else on this forum, on how he calibrates.

On important point, is if you are going to use a flat card as the starting point to make sure the angle of the card to the light and lens doesn't allow extra or remove light during the capture. This is the angle of incidence equals angle of reflection relationship all over again. That is why a 3-D target is preferred, especially one that mirrors your primaary subject matter.

[jfrancho]

Since Benji is using the histogram generated by Photoshop, 18% gray is dead center, regardless of camera make or model.

[Brooks]

If you're moving the camera in close to fill the frame with the grey card, it's important to manually focus the camera on infinity so there is no bellows factor introduced to the exposure.

[AlexisG]

Thank you Benji for sharing your method of calibrating a hand held meter. It helps a lot!