williamkazak wrote:
That is why, if everything is standing still, I put my flash on M while my camera is also on M after I meter for the ambient light with a handheld meter.
Probably the best way to work and understand flash .
I like to learn how the automatic modes work for when things are simply moving too fast
Desmond, you continue to confound the terminology of this subject to the extent that it is confusing, especially to the newbs trying to figure out their Nikon's flash system. In a post earlier you noted that i-TTL doesn't utilize ambient exposure and distance info. That is patently false. Nikon's i-TTL flash exposure control system (and Canon's E-TTL II) does indeed include ambient exposure and distance info. The true beauty of the i-TTL system is that the user can choose to shoot in either TTL mode that does not utilize ambient exposure/distance info or TTL/BL mode that does. Each user should consult their camera/flash manual to learn more about switching between these flash exposure modes.
In the post above this one you presented 4 excellent examples of the differences between TTL and TTL/BL modes (especially with regard to how distance will effect flash exposure when TTL/BL is used... kudos). These images are labeled correctly as "TTL" and "TTL/BL" denoting the modes that the i-TTL system offers the photographer. Following a convention of terminology such as this (in my experience the "i-TTL system and its modes" is used throughout much of Nikonland) will make it easier for many folks to better understand your testing and evaluation, and therefore the i-TTL system itself. Doing so will only add value to your extremely useful research.
In the future I hope you do more testing of how different Nikon DSLR cameras' AF systems effect exposure. Specifically, sensor area mode configuration (Auto Area vs. Dynamic vs. Single), sensor size (the true size, not the brackets we see in the viewfinder ), and cross type vs. linear. As proven earlier in this thread not all Nikon i-TTL based cameras' AF systems effect exposure the same, and at the very least further testing may induce folks to do some simple tests with their own cameras to better understand the extent that their AF system may skew exposure.
Desmond, you continue to confound the terminology of this subject to the extent that it is confusing, especially to the newbs trying to figure out their Nikon's flash system. In a post earlier you noted that i-TTL doesn't utilize ambient exposure and distance info. That is patently false. Nikon's i-TTL flash exposure control system (and Canon's E-TTL II) does indeed include ambient exposure and distance info. The true beauty of the i-TTL system is that the user can choose to shoot in either TTL mode that does not utilize ambient exposure/distance info or TTL/BL mode that does. Each user should consult their camera/flash manual to learn more about switching between these flash exposure modes.
In the post above this one you presented 4 excellent examples of the differences between TTL and TTL/BL modes (especially with regard to how distance will effect flash exposure when TTL/BL is used... kudos). These images are labeled correctly as "TTL" and "TTL/BL" denoting the modes that the i-TTL system offers the photographer. Following a convention of terminology such as this (in my experience the "i-TTL system and its modes" is used throughout much of Nikonland) will make it easier for many folks to better understand your testing and evaluation, and therefore the i-TTL system itself. Doing so will only add value to your extremely useful research.
In the future I hope you do more testing of how different Nikon DSLR cameras' AF systems effect exposure. Specifically, sensor area mode configuration (Auto Area vs. Dynamic vs. Single), sensor size (the true size, not the brackets we see in the viewfinder ), and cross type vs. linear. As proven earlier in this thread not all Nikon i-TTL based cameras' AF systems effect exposure the same, and at the very least further testing may induce folks to do some simple tests with their own cameras to better understand the extent that their AF system may skew exposure.
ok then , You want 'blunt' "TTL" is "i-TTL" - same thing !
Page 37 of the SB800 manual
"TTL indicates "Standard i-TTL flash" in the i-TTL mode " ,
"TTL-BL indicates "i-TTL Automatic Balanced Fill Flash " in the i-TTL mode "
"TTL" and "TTL-BL" are the same thing as "i-TTL" and "i-TTL-BL" , I just leave the first bit out for simplicity .
Therefore "i-TTL" does not use distance info or take the ambient into account .... only "i-TTL-BL" does .
I have a few hundred images , mostly with text on them in my Flash album on photobucket if you want to browse through them .
I also have an album of metering tests
regarding Nikon cameras and focus point effects on exposure .
I have also started a blog and that link is the small write-up on 3D matrix metering .
Here are two of the images I used - camera on a tripod , focus point moved causes up to two stops exposure difference in some situations .
I certainly appreciate any new knowledge on this important information. When things are happening fast, I like to use something other than M on my flash but my camera is always on M. I really don't know what to put the flash mode in for consistancy. My experience suggests that the colors of the subjects influence the desired results of the flash exposure. I am carefully metering the ambient with a hand held meter so I have some basic idea of the exposure. My flash is either going to be fill flash or more with my basic reading intact for ambient. When I tweak for adding the flash, it is the flash EV that I tweak. As I change composition, the flash tweak may or may not remain constant depending on where I stand with my feet or how I reframe the scene (people) in the camera. It all seems nuts to me. Any advice on the flash mode to choose that would be helpful to me?
williamkazak wrote:
I certainly appreciate any new knowledge on this important information. When things are happening fast, I like to use something other than M on my flash but my camera is always on M. I really don't know what to put the flash mode in for consistancy. My experience suggests that the colors of the subjects influence the desired results of the flash exposure. I am carefully metering the ambient with a hand held meter so I have some basic idea of the exposure. My flash is either going to be fill flash or more with my basic reading intact for ambient. When I tweak for adding the flash, it is the flash EV that I tweak. As I change composition, the flash tweak may or may not remain constant depending on where I stand with my feet or how I reframe the scene (people) in the camera. It all seems nuts to me. Any advice on the flash mode to choose that would be helpful to me?...Show more →
Just remember that plain TTL [ i-TTL] flash uses the centre of the frame for metering and it is a set size so a change in subject size can influence it greatly as shown in my TTL vs TTL/BL blog .
I would say TTL/BL will give you greater consistency .
Just remember that it is watching your meter . If your exposure is close to ''neutral'' and the meter moves with a change of lighting TTL/BL will compensate accordingly to try to keep correct exposure on the subject .
Thank you Desmond. It seems, in retrospect, that I started to use the TTL-BL mode by osmosis and because I was reading your test comments here last year. Have you noticed that the colors of the subject alter your results very much in TTL-BL mode?
Also, what happens with the diffusion cap on the flash when the flash is tilted up a bit for bounce with the diffuser cap on in TTL-BL mode when shooting people?
williamkazak wrote:
Thank you Desmond. It seems, in retrospect, that I started to use the TTL-BL mode by osmosis and because I was reading your test comments here last year. Have you noticed that the colors of the subject alter your results very much in TTL-BL mode?
Also, what happens with the diffusion cap on the flash when the flash is tilted up a bit for bounce with the diffuser cap on in TTL-BL mode?
I haven't noticed much with regard to colours - not that I've been paying that much attention The majority of my tests have been with black and white objects for contrast .
As soon as you tilt the flash head it loses the advantage of distance info .
Last week I did some tests with regard to the amount of light thrown forward with the bounce card and diffuser dome on my blog and came to the conclusion that the bounce card [ with wide angle diffuser out ] throws forward about 6% of the total flash output and the diffuser dome about 12.5% .
Now this gives TTL/BL a bit of its advantage back again probably because it gives it a contrast to work with so if can differentiate between the subject and background .
Once you start bouncing the flash backwards and the background and subject 'become one' TTL/Bl starts to 'lose it' and exposes for the brightest object in the focus point diamond and under-exposes with whites - so a bit of forward light still makes it better than TTL .
