Thanks guys. And I knew about the iTTL but I hate how it seems to overcompensate for what I want. Usually it just throws a ton of light where I only want a little. If I don't have the option to get the flash off camera should I just avoid this type of scenario? I feel like I should ask tons of questions while you guys are still awake and able to answer
You asked for it!
Ok, some questions:
- What exposure mode are you using M, A, S, or P?
- What metering mode are you using Spot, Center-weighted, or Matrix.
In your SB-600 manual look at page 26, you want the speedlight in
TTL BL mode, which is fill-flash mode and not straight TTL.
If you want to continue letting the camera make decisions for you.
If you want to take charge and run the show, look at the chart on page 27 of your SB-600 manual. It will be helpful if you can get to the point that you thouroughly understand that chart.
Then go to page 34 of the SB-600 manual and read through page 38 (the manual mode section). Take the time to understand the 3 easy and simple math equations so you can calculate:
- The correct aperture
- The correct flash output level
- and the correct shooting distance.
It's freshman high school math and with a bit of practice you'll be able to do the calculations in your head. The key phrase here is "with a bit of practice". If you blow off spending some tiome learning it, it will never happen and flash will remain a trial and error (mostly error) process for you.
Ok, back to the rear curtain setting but first a note. Look at page 90 of your SB-600 manual and on the left of the page find "Flash Duration". The chart shows, when the SB-600 outputs full power (1/1) the flash of light is only on for about 1/900 of a second. That's about the same as setting youerr shutter to 1/1000 of a second. Notice that as the power setting goes down, the flash duration gets shorter. (1/11,100 at 1/16th power)
That means that even though your camera's shotest flash sync speed maybe 1/200, we can use flash
in much the same way we use shutter speed because of the short flash duration.
The shutter in your camera has 2 curtains. Nikon calls them the front curtain and the rear curtain. For Canon readers, Canon calls them the first and the second curtains. So front = first and rear = second.
Before you trip the shutter the front curtain is covering the image sensor. The rear curtain is above the front curtain.
When you trip the shutter the front curtain drops letting light get to the image sensor. Then the rear curtain drops down and covers the image sensor stopping the exposure.
Both curtains then return to their original positions, ready for the next exposure.
The normal sync mode for flash is timed to when the front curtain is fully open, So at the instant the front curtain is fully open the flash fires. If there is sufficient ambient light and the subject or camera is moving we can record that motion between the time the front curtain was fully open and the rear curtain is not yet full closed. That motion gets recorded in front of the direction of motion and looks really bad.
When we sync on the rear curtain, the flash fires right at the instant before the rear curtain starts to close. Remembering the note above about flash duration, even if we have full power set on the SB-600 it will act like the shutter speed is set to 1/1000 of a second and any camera shake or subject motion will not be recorded during the flash. If we have the speedlight set to a lower power the flash duration is even shorter.
That's why most of the time you want the flash to sync to the rear curtain.
Go here and watch this stop-motion sequence of a shutter in action: Move your cursor across the bottom of the image to see it one frame at a time, it's not a video.
Jeffrey Friedl’s Blog » Nikon D3 Shutter Release in Super Slow Motion
The next thing you will want to Google and research is "dragging the shutter".
