Forums
New posts
Search forums
What's new
New posts
New media
New media comments
New profile posts
Latest activity
Media
New media
New comments
Search media
Members
Current visitors
New profile posts
Search profile posts
Log in
Register
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Install the app
Install
Forums
Learning
Flashes
why are flash photos still grainy?
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="yauman" data-source="post: 275306" data-attributes="member: 15418"><p>Ok, you have to understand how the Nikon CLS system works to get good flash pictures. When you use a flash, the exposure is NOT determined by the camera anymore but by the LENGTH of the light pulse the flash puts out - it's anywhere from 1/1,000 of a second (for lots of light) to 1/40,000 of a sec when very little light is needed. The way it does that is when you press the shutter, it first puts out a "pre-flash" - a short burst of low level light - the camera than "reads" the light from this pre-flash and based on it's ISO setting, it sends out signal to the flash to adjust the power of the light coming out of the flash and that's how it works. (Notice the hot shoe for the flash is not just one contact but 5 - it's a "signal cable.") It doesn't matter what your shutter speed is or what your aperture is. Your shutter speed will always be much longer than the length of the light pulse from the flash. Your aperture will be used to control the depth of field. Only the ISO matters on the camera. The shutter speed will matter not on the subject but on the background exposure as the flash light is good for only up to about 20-25 ft. </p><p></p><p>Now, understanding this, this is what you do to get good flash pictures with your flash switched to TTL mode:</p><p></p><p>1. Set your camera to manual mode - yes do it even if you have always shot in Auto, P, A, or S. Just do it in M!!! Serious!</p><p>2. Set the ISO to 200 as a starting point - with the SB700 it's probably good setting for almost all situations.</p><p>3. Set your shutter speed to 1/200 and leave it there - remember the "exposure speed" is determined by the length of the light pulse. (If you have seen the hi-speed photos of a bullet going thru an apple, it's taken by the camera "B" - setting, ie shutter just opened and the strobe flash at 1/250,000 sec to catch the image of the bullet - flash photography do not depend on the shutter speed, only on the length of the light pulse.</p><p>4. Set your aperture to the depth of field you like - this is your only adjustment. So, for people portraits, set it to f4 or f5.6. Play with it.</p><p></p><p>Now, with your flash on, take a picture - you'll get great shots. If you want brighter, up the ISO. Also, look at the "+/- EV" adjustment on the SB700, +ev gives you a bright picture, -ev will darken it.</p><p></p><p>Now, if you are using flash in daylight as a fill in light you can adjust the shutter speed to change how bright or dark your background is - but it will have not much impact on your subject as it's lighted by your speed light which overpowers all the other light. Be care not to set the shutter speed to high, I don't know what the limit for the 5100 but for my 7100, it's 1/250 - above that limit, you'll start to see dark bands across the image - then you'll have to go into the "FP" mode - Nikon's version of High Speed Sync - but that's for Advance SpeedLite class!</p><p></p><p>Hope that helps.</p></blockquote><p></p>
[QUOTE="yauman, post: 275306, member: 15418"] Ok, you have to understand how the Nikon CLS system works to get good flash pictures. When you use a flash, the exposure is NOT determined by the camera anymore but by the LENGTH of the light pulse the flash puts out - it's anywhere from 1/1,000 of a second (for lots of light) to 1/40,000 of a sec when very little light is needed. The way it does that is when you press the shutter, it first puts out a "pre-flash" - a short burst of low level light - the camera than "reads" the light from this pre-flash and based on it's ISO setting, it sends out signal to the flash to adjust the power of the light coming out of the flash and that's how it works. (Notice the hot shoe for the flash is not just one contact but 5 - it's a "signal cable.") It doesn't matter what your shutter speed is or what your aperture is. Your shutter speed will always be much longer than the length of the light pulse from the flash. Your aperture will be used to control the depth of field. Only the ISO matters on the camera. The shutter speed will matter not on the subject but on the background exposure as the flash light is good for only up to about 20-25 ft. Now, understanding this, this is what you do to get good flash pictures with your flash switched to TTL mode: 1. Set your camera to manual mode - yes do it even if you have always shot in Auto, P, A, or S. Just do it in M!!! Serious! 2. Set the ISO to 200 as a starting point - with the SB700 it's probably good setting for almost all situations. 3. Set your shutter speed to 1/200 and leave it there - remember the "exposure speed" is determined by the length of the light pulse. (If you have seen the hi-speed photos of a bullet going thru an apple, it's taken by the camera "B" - setting, ie shutter just opened and the strobe flash at 1/250,000 sec to catch the image of the bullet - flash photography do not depend on the shutter speed, only on the length of the light pulse. 4. Set your aperture to the depth of field you like - this is your only adjustment. So, for people portraits, set it to f4 or f5.6. Play with it. Now, with your flash on, take a picture - you'll get great shots. If you want brighter, up the ISO. Also, look at the "+/- EV" adjustment on the SB700, +ev gives you a bright picture, -ev will darken it. Now, if you are using flash in daylight as a fill in light you can adjust the shutter speed to change how bright or dark your background is - but it will have not much impact on your subject as it's lighted by your speed light which overpowers all the other light. Be care not to set the shutter speed to high, I don't know what the limit for the 5100 but for my 7100, it's 1/250 - above that limit, you'll start to see dark bands across the image - then you'll have to go into the "FP" mode - Nikon's version of High Speed Sync - but that's for Advance SpeedLite class! Hope that helps. [/QUOTE]
Verification
Post reply
Forums
Learning
Flashes
why are flash photos still grainy?
Top
