Rebel 2000 Metering, AIM Focusing and FEL Question

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Hello:

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:

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.

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.

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

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

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?

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?

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.

Thanks.

--Joel Turner

-- Joel Turner (jturner421@aol.com), February 27, 2002

Answers

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

"1. ...do you know if the Elan 7 can achieve partial metering by selecting an AF point manually."

Yes, it can.

"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."

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.

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

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.

"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?"

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

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?"

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.

-- Jim Strutz (j.strutz@gci.net), February 27, 2002.


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.

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?

Rod Barnett

-- Rod Barnett (rod.j.barnett@bt.com), February 28, 2002.


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

" 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. "

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?

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.

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. :)

-- Joel Turner (jturner421@aol.com), February 28, 2002.


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).

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.

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.

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.

-- Jim Strutz (j.strutz@gci.net), February 28, 2002.


Hi Joel,

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

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.

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.

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.

4. As I said before, FE Lock is always measured on the partial metering area, i.e. the 10% or so in the center.

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.

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).

Hope this helps.

-- Peter Langfelder (plangfel@insti.physics.sunysb.edu), March 26, 2002.



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