patrickphoto wrote:
ANY TTL system by any manufacturer can, and most do use distance. just like thyrister systems they prefer to start off with a mathematic exposure. distance, light output, and sensitivity, aperature and a little love.
Nikon and Canon TTL don't use distance info , only their newer TTL/BL and E-TTL do , and only when the flash head is pointing forward . They seem to 'remember' the distance info when the flash head is tilted because pure-bounce [ backwards ] under-exposes while using a bounce card does not - so perhaps they use the distance info in this case to determine minimum output .
Only the newer systems take shutter speed into account as well .
Am I correct when I say that the F4 doesn't have ttl bl and yet has 3d metering that takes into account the distance information relayed from D type lenses?
patrickphoto wrote:
Am I correct when I say that the F4 doesn't have ttl bl and yet has 3d metering that takes into account the distance information relayed from D type lenses?
I have no idea how the film cameras work with flash
As far as I know 3D matrix metering takes distance info into account when calculating for exposure of the subject which is why the D80 blew highlights quite often - it exposed too much for the focus point .
So 3D matrix metering uses distance info for exposure - but normal TTL flash doesn't use distance info when calculating flash output .
I will agree that with DSLR's, the statements you make are true, but remember that flash is just flash, and there are several film cameras out there that don't necessarily adhere to the current settings and functionalities listed for "slr's".
patrickphoto wrote:
I will agree that with DSLR's, the statements you make are true, but remember that flash is just flash, and there are several film cameras out there that don't necessarily adhere to the current settings and functionalities listed for "slr's".
I won't make any statements with regard to anything that I haven't tested .
But it would be hard to imagine that film cameras were using technology that they are only starting to use in digital .
Apparently TTL/BL was designed in the 80's for back-lit subjects and the distance info was introduced as a back-up for the likely event that the pre-flash reading would fail due to the bright back-lighting .
I think Nikon soon realized the power of distance info and the fact that they were wasting advanced technology on limited applications and then modified it to work in any situation .
I think the D100 was the last camera to under-expose TTL/BL when used indoors since it still had the old equation designed to balance the subject with the background [ If the background was the same brightness / darkness it simply fired at its weakest since it had nothing to balance with ] .
I wouldn't know when the F4 was released or what technology it used .... and wouldn;t be able to afford to do all the tests I've done with film !
Just to update my progressive understanding of the system , the D40's three focus points in the centre simply define the outer limits of the focus point diamond that it meters off - my latest video might shed some light on that .
DesmondD wrote:
Nikon and Canon TTL don't use distance info , only their newer TTL/BL and E-TTL do,
To clarify... (Nikon's) TTL/BL is an exposure function, whereas Canon's e-TTL is a metering system. Not sure it's correct to compare the two (kinda like comparing apples to food processors ).
Nikon's Matrix metering capabilities do indeed include distance info (with D/G series lenses), and have done so for many years. The F4 with its early Matrix metering technology coupled with the SB-24 (the first Nikon flash to include distance info in its flash exposure) were in their day really pretty good together.
patrickphoto wrote:
Am I correct when I say that the F4 doesn't have ttl bl and yet has 3d metering that takes into account the distance information relayed from D type lenses?
The F4 can do TTL/BL with flashes from the SB-24 forward (including today's SBXXX series). And the F4 utilizes distance info in flash exposure (with lenses that provide distance info). Of course, the TTL/BL capability of the F4/SB24 was somewhat rudimentary compared to today's i-TTL/current DSLR's (technology marches on )
It should be noted that Nikon DSLR's d-TTL and (the far better) i-TTL are completely different critters from film SLR's systems. Film SLR's utilize OTF (off the film) metering for determining flash exposure, while current DSLR's use flash exposure meters (coupled with pre-flashes, something film SLR's with their OTF didn't require). This difference alone can make comparing the two systems challenging.
DesmondD wrote:
As far as I know 3D matrix metering takes distance info into account when calculating for exposure of the subject which is why the D80 blew highlights quite often - it exposed too much for the focus point .
Curious... blown highlights using flash/Matrix metering is not something I've seen alot of with our D80/SB800 combo. My experience is that that combo does a pretty good job.
I am wondering if anyone is using the A setting on the SB-800 flash. By not "talking" to the camera body, the flash itself calculates the distance and then turns itself off once the correct amount of light is thrown out there as I understand it. This is like the old Vivitar 283/285. They worked for me with film but I could not get them to work with my D70s bodies so I had to eventually purchase the SB-800 flash units. Now, I use D300 bodies and my F6.
It seems to me that with the camera body doing the interpretation on iTTL and TTL-bl, all of these tests become mandatory because no one can figure out what that camera body is actually doing and consistent results are not easy to achieve.
williamkazak wrote:
I am wondering if anyone is using the A setting on the SB-800 flash. By not "talking" to the camera body, the flash itself calculates the distance and then turns itself off once the correct amount of light is thrown out there as I understand it. This is like the old Vivitar 283/285. They worked for me with film but I could not get them to work with my D70s bodies so I had to eventually purchase the SB-800 flash units. Now, I use D300 bodies and my F6.
It seems to me that with the camera body doing the interpretation on iTTL and TTL-bl, all of these tests become mandatory because no one can figure out what that camera body is actually doing and consistent results are not easy to achieve....Show more →
It's a bit like having the camera in full-auto mode these days - trying to second-guess the camera's program .... which changes a bit with each new model
But the old "A" mode never used distance info , just the reflected reading which would have made it fairly consistent in its output with a set scene and various focal lengths , since it used a fixed angle to read from .
It also never took ambient into account as the newer systems do .
I have found the "A" mode quite useful with a cheap wireless flash trigger when the flash is perhaps lighting something that is not central - since it has its own built in sensor it can meter for itself as long as you have set the correct iso and aperture into it .
bitmaker wrote:
To clarify... (Nikon's) TTL/BL is an exposure function, whereas Canon's e-TTL is a metering system. Not sure it's correct to compare the two (kinda like comparing apples to food processors ).
The F4 can do TTL/BL with flashes from the SB-24 forward (including today's SBXXX series). And the F4 utilizes distance info in flash exposure (with lenses that provide distance info). Of course, the TTL/BL capability of the F4/SB24 was somewhat rudimentary compared to today's i-TTL/current DSLR's (technology marches on )
It should be noted that Nikon DSLR's d-TTL and (the far better) i-TTL are completely different critters from film SLR's systems. Film SLR's utilize OTF (off the film) metering for determining flash exposure, while current DSLR's use flash exposure meters (coupled with pre-flashes, something film SLR's with their OTF didn't require). This difference alone can make comparing the two systems challenging.
Curious... blown highlights using flash/Matrix metering is not something I've seen alot of with our D80/SB800 combo. My experience is that that combo does a pretty good job.
I only just saw this post . I was discussing flash systems rather than matrix metering systems .
I also looked up Canon's E-TTLii flash the other day and I'm pretty convinced it is a flash system and not a metering system as you suggest .
The D80 will be fine with flash and an under-exposed ambient , it's the ambient exposure it blows highlights with .
The D90 seems to limit its exposure difference to around two stops at most with the same scene .
DesmondD wrote:
I was discussing flash systems rather than matrix metering systems .
Indeed, it's difficult to discuss any flash system without including the all important metering system that controls it.
DesmondD wrote:
I also looked up Canon's E-TTLii flash the other day and I'm pretty convinced it is a flash system and not a metering system as you suggest .
The foundation of any flash system is its metering system. It is the metering system that measures the ambient exposure, works with the flash sensor (in digital cameras) to evaluate the pre-flash(es), gains distance info from the lens (when discussing Nikon's i-TTL and Canon's E-TTL II, both with appropriate lenses), and handshakes with the algorithms stored in the camera to allow the system to deliver (what it thinks is) the proper (or.. what we want to be balanced) exposure. Also, as this discussion has proven, the AF area mode one uses can have some input into flash/ambient exposure balance.
DesmondD wrote:
The D80 will be fine with flash and an under-exposed ambient , it's the ambient exposure it blows highlights with .
I'll reiterate that blown highlights (whether ambient or flash exposue) is not something I've had a problem with using the D80/SB800. The matrix meter's algorithms for balancing flash and ambient exposure generally work well for me.
bitmaker wrote
The foundation of any flash system is its metering system. It is the metering system that measures the ambient exposure, works with the flash sensor (in digital cameras) to evaluate the pre-flash(es), gains distance info from the lens (when discussing Nikon's i-TTL and Canon's E-TTL II, both with appropriate lenses), and handshakes with the algorithms stored in the camera to allow the system to deliver (what it thinks is) the proper (or.. what we want to be balanced) exposure.
Now you made me look up the word 'semantics' .
Here's a quote from the link you provided " E-TTL stands for "Evaluative Through-The-Lens" flash exposure control " .
Now I won't profess to have done any tests with Canon's flash system [ maybe like comparing oranges to 'lemons' in the past ] but the description of E-TTL sounds very much like a copy of TTL/BL mode .
Nikon's I-TTL does not use distance info .
i-TTL does not take the ambient into account .
Russ MacDonald has a bit of info on it TTL flash .
TTL-BL is very similar to E-TTL [ more like the other way around ] .
They both take ambient into account and use distance info so I think the comparison is reasonable .
Adam73 wrote:
Wow Desmond, I have been watching your youtube videos for a while now and didn't realize you were on FM. Welcome. I really enjoy your tutorials.
-Adam
Thanks very much When I started learning more about the subject and realized that there was a lot of confused information out there I decided to sign up on all the major forums and share what I know .
My main TTL/BL video is due for an update ...
But I've added a 'patch' video to help explain the 'focus point diamond' metering .
Keep in mind though that much of this is "deduced" information - I don't receive any extra information besides what my tests indicate
DesmondD wrote:
... but the description of E-TTL sounds very much like a copy of TTL/BL mode .
Canon's E-TTL (and version II) are exposure control systems (for flash), just as Nikon's i-TTL is. As you pointed out, TTL/BL is a mode... a function that can be turned on or off within Nikon's i-TTL.
DesmondD wrote:
Nikon's I-TTL does not use distance info .
i-TTL does not take the ambient into account .
The following descriptions from Nikon: http://www.nikonusa.com/Learn-And-Explore/Nikon-Camera-Technology/ftlzi50a/1/i-TTL-Balanced-Fill-flash.html :
"Nikon's i-TTL (intelligent through-the-lens) Balanced Fill-Flash automatically balances the output of the Nikon Speedlight and the scene's ambient light." and "Combined with information from the camera's 3D Color Matrix metering system, the information is analyzed to adjust flash output to balance the scene's ambient light."
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.
Thanks Desmond. There is a lot of conflicted information out there and to have videos showing the results rather than just reading an article helps a lot. Again thanks for taking the time to do it. If no one else has said it, I will. I appreciate your hard, selfless work. Very much appreciated.
Adam73 wrote:
Thanks Desmond. There is a lot of conflicted information out there and to have videos showing the results rather than just reading an article helps a lot. Again thanks for taking the time to do it. If no one else has said it, I will. I appreciate your hard, selfless work. Very much appreciated.
-Adam
Thanks very much for the support - it makes it more worthwhile . We can post links to what others say and get nowhere - or we can show proof via samples and close it there
I like to only speak on what I know and have tested - not what others say .
bitmaker wrote:
Canon's E-TTL (and version II) are exposure control systems (for flash), just as Nikon's i-TTL is. As you pointed out, TTL/BL is a mode... a function that can be turned on or off within Nikon's i-TTL.
1.) The following descriptions from Nikon: http://www.nikonusa.com/Learn-And-Explore/Nikon-Camera-Technology/ftlzi50a/1/i-TTL-Balanced-Fill-flash.html :
"Nikon's i-TTL (intelligent through-the-lens) Balanced Fill-Flash automatically balances the output of the Nikon Speedlight and the scene's ambient light." and "Combined with information from the camera's 3D Color Matrix metering system, the information is analyzed to adjust flash output to balance the scene's ambient light."
1.) They are talking about TTL/BL there . That's what the 'balanced fill flash ' part of the description "BL" . Plain i-TTL does not use distance info or balance with the ambient .
Believe me , I've done tests on both systems .
2.) Yes , that's 3D matrix metering - nothing to do with the flash system except with regard to where it deems correct exposure of the ambient to be and how TTL/BL responds to that . I did a blog on 3D matrix metering here
And I did a video on the difference that simply switching between metering modes affects TTL/BL output because it is ''watching the meter ''
).