Rebel 2000 Metering, AIM Focusing and FEL Question

[joel_turner]

Hello:

 

<p>

 

I have a Rebel 2000 that I have used for the past 3 months and am trying to better understand how the equipment works so I can be more creative with it. I understand that the system has a 7 point autofocus system with AE lock and with the appropriate EX flash ( I have a 380EX) E-TTL metering. My questions are:

 

<p>

 

1. In partial metering mode with out flash, can I select the focus point that I want metered manually or should I just point the middle AF point at the subject which I understand covers approximately 9.5%, press the shutter halfway to focus, press AE lock to meter that area and recompose. If the Rebel can not do this, do you know if the Elan 7 can achieve partial metering by selecting an AF point manually.

 

<p>

 

2. Is AE lock available with Manual mode. If so, does it act the same way as in the other creative modes by partially metering the 9.5% of the viewscreen.

 

<p>

 

3. When using an EX flash, does FEL lock supplant AE lock? If so, is it using partial metering or 35 zone matrix metering?

 

<p>

 

4. Is FEL lock biased towards the active AF point or towards the 9.5% middle spot in the viewfinder?

 

<p>

 

5. I know that in AE mode sans flash, you can bracket effectively through exposure compensation or the AEB function. If the camera defaults to matrix metering using flash, will exposure compensation really work since you do not have an idea how the camera is making it's exposure decision? Does it use matrix for all of creative functions such as AV with flash?

 

<p>

 

6. I also understand that the Rebel does not have flash compensation. In order to adjust that, I would to reset the ISO setting for that particular shot in conjunction with exposure compensation. Since the topic has been covered previously I don't need to know the details but I do have two questions related to it. If I reset the iso for that particular shot, will it affect the rest of the shots on that roll or only that particular one assuming I reset the iso back to it's original setting? Assuming print film, do I need to give the printer any special instructions while processing?

 

<p>

 

I apologize for all the questions and I have tried to search the photo.net archives for these answers, but I was unable to find them in the combination that I am posing them. If you can point me towards the appropriate reference thread or site, that would be greatly appreciated.

 

<p>

 

Thanks.

 

<p>

 

--Joel Turner

[jimstrutz]

I know the answer to a few of these, but not all.

 

<p>

 

"1. ...do you know if the Elan 7 can achieve partial metering by

selecting an AF point manually."

 

<p>

 

Yes, it can.

 

<p>

 

"2. Is AE lock available with Manual mode. If so, does it act the

same way as in the other creative modes by partially metering the

9.5% of the viewscreen."

 

<p>

 

In manual mode there is no AE, so there is no AE lock. As I

understand it, in manual mode all exposure determination is done with

Center Weighted Averaging. I don't think partial metering is

available, but I might be wrong.

 

<p>

 

"3. When using an EX flash, does FEL lock supplant AE lock? If so, is

it using partial metering or 35 zone matrix metering?"

 

<p>

 

FEL does supplant AEL. Flash metering with the Rebel 2000 and the

380EX is always done E-TTL. So flash metering is with the 35 zone

evaluative meter. Partial metering is not available.

 

<p>

 

"5. I know that in AE mode sans flash, you can bracket effectively

through exposure compensation or the AEB function. If the camera

defaults to matrix metering using flash, will exposure compensation

really work since you do not have an idea how the camera is making

it's exposure decision? Does it use matrix for all of creative

functions such as AV with flash?"

 

<p>

 

Exposure Comp still works even though you/we have little knowledge of

how exposure is determined with the evaluative meter. Without flash,

evaluative metering is always used except in manual mode or when

pressing the AEL button. With flash, the AEL button does not disable

evaluative metering. In manual mode, the ambient exposure is center

weighted but the flash is still evaluative

 

<p>

 

6. "...If I reset the iso for that particular shot, will it affect

the rest of the shots on that roll or only that particular one

assuming I reset the iso back to it's original setting? Assuming

print film, do I need to give the printer any special instructions

while processing?"

 

<p>

 

Resetting the ISO only effects the shot(s) you are uising it for.

When you set it back it is canceled & does not effect the rest of the

roll. Do not give any special instructions to your printer. You

don't want him pushing or pulling the film processing. That would

just be a poor attempt to undo the effect that you were trying to

accomplish.

[rod_barnett]

According to the manual partial does work in manual mode, here is a

relevant quote

"If the Command Dial is set to M you can check the reading on the

scale to see the difference between the manual setting and the

exposure data computed with the partial metering function"

As it is in manual mode you then have to make the decision which

information to use and then set the exposure.

 

<p>

 

I think I have read every bit of information on the net regarding FEL

and it is the one subject where the seems to be no agreeement.

I have also e mailed Canon and received conflicting information on how

it works, the last one stating that partial metering is used.

I would be very interested to hear from any users how they use this

function.For example if you are taking a portrait of a white face

against various backgrounds using FEL would you compensate by one stop

as you would using partial metering without flash.If this is not the

case how does the background affect the exposure?

 

<p>

 

Rod Barnett

[joel_turner]

Jim, Thanks for your response. According to the Canon flash FAQ:

 

<p>

 

" FEL works by issuing a preflash when the AE lock button is pressed.

The camera then stores flash exposure data, biased towards either the

current focus point or the central focus point, for a 16 second

period or for as long as you keep the shutter release pressed

halfway. During this time you can recompose the photo or you can

adjust the aperture and shutter speed (overriding AE lock, which is

set when you press the AE lock button, if you like). FEL is thus

useful for taking photos in which the subject is not covered by one

of the focus points or photos containing reflective surfaces which

can fool flash metering or certain cases in which the subject is

moving. It�s also useful for scenes in which you want to bias the

flash exposure to something other than the current focus point. "

 

<p>

 

That's why I'm confused. If it fires a pre-flash to take a reading,

why would that be evaluative rather than partial? Assuming I have the

flash on, if I focus on something without using FEL, I'm using E-TTL

for the entire scene which defaults to evaluative metering. Now I

pick something else, press FEL lock, wouldn't that by default assume

that I have taken a partial reading on a particular object to achieve

the best flash exposure for the subject? If so, wouldn't the rest of

the scene be exposed relative to the part of the scene partially

metered? If not, how is the exposure determined? Am I missing

something?

 

<p>

 

Rod, As you can see I'm confused about FEL also. What makes it worse

is I don't have a camera or a flash with FEC so even if I understand

how to compensate, the method to do so is cumbersome.

 

<p>

 

I think I'm finding out very quickly that while my Rebel is a nice

camera, as I start to get more creative, I'm going to have to upgrade

to at least an Elan 7 to have more control over the final exposure.

That's what birthdays are for. :)

[jimstrutz]

Lack of FEC has always been a problem with the Rebel series cameas,

and is a good reason to upgrade. Of coures FEC can be had with

430EZ, 540EZ (no E-TTL) or the 550EX (or Sigma EF-500 Super).

 

<p>

 

There has been a lot of arguments about FEL. Usually centered

around, "Does FEL use partial metering?" I contend that it does not,

and nothing Canon has ever published says otherwise. E-TTL is by

nature *Evaulative* TTL flash metering. It can't do evaluative

metering with only one metering area. There is nothing to evaluate

and it wouldn't be evaluative metering by Canon's definition. What

Canon has always stated is the E-TTL biases the flash exposure to the

active AF point, they never say that it uses the partial meter for

flash.

 

<p>

 

E-TTL flash exposure always evaluates all the areas in determining

the proper exposure. It does consider the area surrounding the

active AF point more however. FEL doesn't change this.

 

<p>

 

In the end I suspect this is a moot point. Whether flash exposure is

biased towards the AF area, or the area surrounding the AF point is

used exclusively, the flash exposure probably wouldn't change much.

[peter_langfelder1]

Hi Joel,

 

<p>

 

I have a Rebel 2K wih 550 EX. To answer your questions:

 

<p>

 

1. Rebel always partial-meters on the CENTRE; on Elan 7 (and II as

well) you can decide via a custom function, hether you want the

partial meter linked to the center or teh active focusing point.

 

<p>

 

2. AE Lock is not available in Manual mode, but if you press the *

button (without flash), the camera will measure the scene using the

partial meter and will display your set exposure vs. the metered one

on the bar graph for several seconds. In other words, you do get the

partial metering in Manual mode, but you have to set the aperture and

shutter speed to match the camera's recommendation.

 

<p>

 

3. FE Lock and AE lock are set together. FE Lock measures the flash

exposure using the partial meter (just as AE Lock does), NOT the

evaluative meter.

 

<p>

 

4. As I said before, FE Lock is always measured on the partial

metering area, i.e. the 10% or so in the center.

 

<p>

 

5. If you are in any mode except Manual, the camera will always use

matrix metering. Exposure compensation with flash will work on abient

exposure only, i.e. the flash exposure will be the same (assuming your

subject doesn't move while bracketing). Again, the camera always uses

matrix meterng UNLESS you are in the Manual mode OR you use AE Lock

and/or FE Lock.

 

<p>

 

6. ISO and exp. compensation only affect the picture which is taken

with a particular setting, NEVER any future pictures for which you

change the settings. Thus, if you return ISO and exp. compensation

back to normal, subsequent pictures will be taken without any extra

flash exposure compensation. The question about special instructions

is a tough one. The printing machines usually compensate for any

over/underexposure of film - whether it was intentional or accidental

- and will print every print with an "average" exposure (unless the

operators turn this correction off). Therefore, you may bracket your

pictures but your photos may come back from the lab looking all the

same. You would be better of using slide film if you want to see the

effects of bracketing. Alternatively, you can try to ask your photo

finisher to fix the machine exposure based on your first frame of the

roll (make sure that frame is exposed properly) and disable any

corrections afterwards. Depending on where you process your pictures,

they may or may not understand your request (never mind actually

complying with it).

 

<p>

 

Hope this helps.