lighting ratios (outdoors)


Status
Not open for further replies.
As mentioned earlier, simple and easy way to achieve it is

Set your flash to standard TTL.
If you are in A mode on your camera, dial in -3eV exposure compensation on the camera (this will increase your shutter speed - you may need to go into FP mode if the shutter speed goes above your x-sync speed). If you are in M mode, adjust your aperture/shutter speed so that the background will be underexposed by 3eV.
Take the shot.




Yes, the main disadvantage of FP mode is the flash power is reduced to approx. 1/8 power.

ok very clear explanation.will try it.
so if the flash goes into FP mode, does that mean i will have to move nearer to my subject to compose the shot since power reduced to 1/8?
 

ok very clear explanation.will try it.
so if the flash goes into FP mode, does that mean i will have to move nearer to my subject to compose the shot since power reduced to 1/8?

Depends on what your focal length and settings are. Your SB-800 will tell you it's working range on the back lcd and it will adjust the displayed range when it goes into FP mode.
 

if you guys can, take a good read at this book by daniel lezano and bjorn thomassen

100 WAYS TO TAKE BETTER PORTRAIT PHOTOGRAPHS

on page 58, he mentioned a technique call keyshifting

he only mentioned a 3 stop compensation for background vs subject.but to a noob like me, i'm juggling in my mind how and WHAT to set on my flash and camera.

man...i'm almost done reading all the photography books bought from kinokuniya.:bsmilie:
Is it 1:3 ratio or 3-stop compensation? They are not the same.

If you read the article which I've sent to you, there is a mention of 1:3 as the "classic" ratio for natural looking portrait. That means that the fill-light is at 1/3 strength of the ambient light. (It does not means that there is 3-stop difference.) You simply do a -1.33 to -1.67 EV flash compensation to acheive this effect. (To translate 1:3 ratio to EV, -1.732EV flash compensation)

Play around with the flash compensation and exposure compensation and you will get a hang of it.

I believe the Nikon's TTL/BL mode takes that into account automatically.

BC
 

Is it 1:3 ratio or 3-stop compensation? They are not the same.

If you read the article which I've sent to you, there is a mention of 1:3 as the "classic" ratio for natural looking portrait. That means that the fill-light is at 1/3 strength of the ambient light. (It does not means that there is 3-stop difference.) You simply do a -1.33 to -1.67 EV flash compensation to acheive this effect. (To translate 1:3 ratio to EV, -1.732EV flash compensation)

Play around with the flash compensation and exposure compensation and you will get a hang of it.

I believe the Nikon's TTL/BL mode takes that into account automatically.

BC


teach me how to get the calculated values down to the decimel points.

i re read the book, yes, it's a 3 stop difference.
the diff between the ambient and the fill flash ratio is the crux of key shifting.
 

BC and jeanie, I think you two are talking about two different things.

BC, you are talking about using flash as a fill light in an outdoor portrait; while jeanie seems to be talking about underexposing the background while using a flash to expose the subject correctly to make the subject stand out - which is the scenario that you want to create jeanie ?
 

BC and jeanie, I think you two are talking about two different things.

BC, you are talking about using flash as a fill light in an outdoor portrait; while jeanie seems to be talking about underexposing the background while using a flash to expose the subject correctly to make the subject stand out - which is the scenario that you want to create jeanie ?


key shift.that's the jargon from the book.
i seriously dont know is there really a difference between the 2 techniques u mentioned though i absolutely know what you mean.
 

It has been mentioned before in this thread. Play around with your exposure compensation (-3 stops for surrounding) and flash exposure compensation (which ever stops you want to correctly expose your subject).

Also, I would suggest you use Av instead of manual to start with first. In that case, you can concentrate on the EC and FEC without having to worry too much on the manual settings.
 

BC and jeanie, I think you two are talking about two different things.

BC, you are talking about using flash as a fill light in an outdoor portrait; while jeanie seems to be talking about underexposing the background while using a flash to expose the subject correctly to make the subject stand out - which is the scenario that you want to create jeanie ?

Yes, you are right... it's different thing. ;p

Missed the key word... keyshifting.

BC
 

It has been mentioned before in this thread. Play around with your exposure compensation (-3 stops for surrounding) and flash exposure compensation (which ever stops you want to correctly expose your subject).

Also, I would suggest you use Av instead of manual to start with first. In that case, you can concentrate on the EC and FEC without having to worry too much on the manual settings.

av= aperture?
 

teach me how to get the calculated values down to the decimel points.

i re read the book, yes, it's a 3 stop difference.
the diff between the ambient and the fill flash ratio is the crux of key shifting.

3 stop difference... now... it is not so straight forward.

You subject will now be litted by both the flash and the ambient light. The only way to can accurately meter 3 stop difference is using a light meter and set the aperture, shutter speed and flash power manually.

Otherwise, you will just have to use the flash and exposure compensation to approximately get 3 stop difference. Remember that the exposure and flash compensation is based on compensating what the camera think is the correct exposure (matrix metering and TTL) and not based on the metered value of subject and background.

BC
 

scag,

i have a light meter.so now, teach me how to do it.
 

Yep. Aperature Priority. I'm not sure if you are a Canon user though...apologies.

me on the dark side....:bsmilie:
 

wah lau jeanie, you have a light meter, just use it lor.

use camera meter to meter the bg exposure.
set camera to M and under exposed the bg to -3 stops
switch flash to M and use the light meter to get aperture value for your flash.
move flash or set flash intensity until you get the correct aperture value.

voilà
 

wah lau jeanie, you have a light meter, just use it lor.

use camera meter to meter the bg exposure.
set camera to M and under exposed the bg to -3 stops
switch flash to M and use the light meter to get aperture value for your flash.
move flash or set flash intensity until you get the correct aperture value.

voilà

if i set my flash to M, i just press the 'test' button to fire the flash and read off the light meter right?so what if the light meter shows f11(for eg), whereas my ambient off my d200 shows f8 1/250?
 

if i set my flash to M, i just press the 'test' button to fire the flash and read off the light meter right?so what if the light meter shows f11(for eg), whereas my ambient off my d200 shows f8 1/250?

yes press the test button to trigger your flash.

if light meter says f11, but you want f8 then either
1. set flash intensity to 1:2 if currently at full
or
2. physically move flash futher away from subject
 

yes press the test button to trigger your flash.

if light meter says f11, but you want f8 then either
1. set flash intensity to 1:2 if currently at full
or
2. physically move flash futher away from subject


i got the idea in mind.but at actualy shoot, i sure gabra.:bsmilie:
 

if i set my flash to M, i just press the 'test' button to fire the flash and read off the light meter right?so what if the light meter shows f11(for eg), whereas my ambient off my d200 shows f8 1/250?

Adjust the power of the flash to get the exposure you want.

1 to 1/2 to 1/4 to 1/16.... are 1-stop intervals


Let's say your enbient is ISO100 f/8 1/250, you want your subject to be 3 stop higher, adjust your flash till you achieve ISO100 f/22 1/250 (set your camera at this setting). (If your light meter says f/11, you need to up the flash power by 2 stop... say from 1/16 to 1/2)

BC
 

Status
Not open for further replies.