Canon FD metering question

[petrovski]

OK, I have a question regarding Canon FTb-N metering and how it

works. I understand that the circle in the square, TTL, meters 12%.

But what does this mean? How exactly does it meter? I am considering

getting a spot meter, but for now, since i have little money, I need

to rely on my FTb. Please help me understand how metering works on

this camera!!!

thanks

peter

[mark_houlder2]

it sounds like a partial meter - like a spot meter, but with a big spot. it basically means the meter will only measure the light inside that circle, any other part of the frame will be ignored for metering purposes. the 12% will refer to the area of the frame that the circle covers. TTL means Through The Lens, meaning the meter measures light coming through the lens, so if you use filters, for instance, the meter will still give correct readings.

[mark_dyson3]

I have an FTB (not "n") but I think apart from cosmetic changes they're the same camera...

 

Metering is taken from the central rectangle (slightly dimmed area) ONLY, pretty much like a spot meter but over a wider area. The reason for the darker area is that there's a semi-silvered mirror embedded in the focussing screen which reflects a small percentage of light onto the metering photocell....

 

Cheers,

Mark.

[peter_bovington]

Sounds like you don't have a manual for the camera (?).

 

If the FTb and FTb-N are indeed the same in regards to metering (there is another thread on this site that suggests this is so), then maybe the manual for the FTb might be of use? You can find one at http://www.canonfd.com/pdf/ftb.pdf

[john_wire]

It's the entire rectangle area.

 

Point the camera at different subjects and watch the meter needle deflect depending on their reflective characteristics as you move them into and out of the rectangle. A good spot meter is expensive, much more than your camera body which has a very adequate and accurate meter.

 

An additional lens would be a better investment IMHO.

 

Regards.

[jtk]

I think your best investment would be to take the camera to a repair shop that advertises service to professionals. Have the meter and shutter calibrated.

 

Old Canons have issues around antique batteries and, like all other old SLRs and meters, increasingly with aging photocells. If you get a meter, get a new one for that reason.

[john_wire]

Peter, I have two old FTBn's that have matching meter responses and they are accurate. Expose a roll of film yourself to check the meter. You may save some money. Regards.

[peter_white2]

The slightly dark horizontal rectangle in the center is the area that the meter reads. It's 12% because that grey rectangle takes up 12% of the screen area.

 

I sold my FTb in the early eighties so it's been a while. But I think it's pretty much the same as my F-1. On the right (or left) side is a scale displaying F stops. There's a needle that responds to light level, ASA/DIN setting, and shutter speed. Then there's a circle that responds to aperture setting.

 

When you've set the ASA correctly and matched the circle with the needle, the meter is telling you what setting to use to expose the subject in the grey rectangle to a middle grey. Just find a portion of the subject that you would like to have right in the middle of the grey scale, half way between solid black and washed out white in your slide or negative, place the grey rectangle on that area, make your reading and set the shutter speed and aperture, and then frame the shot as you like and take the picture.

 

If there's nothing in the frame that you want middle grey, try to find an area of highh contrast betrween black and white and place the rectangle across it 50/50. You can also meter a black area and close down two stops or meter a white area and over-expose two stops, depending on the film you're using. Bracket each shot, especially while you're getting used to the camera. Take lots of notes, and then compare the results against your notes.

 

It won't take long before the FTb becomes very fast to work with. Just takes a bit of practice. It's a great camera. Have fun.

[john_wire]

Hi Peter W, a fine description for using the FTb meter. I never feel I have the exposure as "right" in the newer non-match needle exposure systems as I did with the FTb. The real spot meters are a pain to use quickly compared to the 12% internal meter. Regards.

[mukul_dube]

I have found this "semi-spot" metering system to be an excellent one. I can, for example, go up to whatever it is I want to expose correctly, then move back and make the exposure. Or if the main subject is not in the centre of the frame, I can take a reading for that (or that person), then compose as I want and expose with the same reading. Since the field of view is relatively narrow, it is also possible with this meter to take readings from several places which are to be in the frame -- and then average or bracket, as needed. My FTbN was bought in 1975. To get readings for ASA 100, I must set it to a film speed of ASA 650: but then it is bang on. The mercury cell problem is common to many cameras and meters of that time. I use an adapter, a hollow 625 shell with a Schottky diode, into which I can put a 1.5V silver oxide cell so that output becomes 1.35V. I also have an EF of the same vintage, but the exposures I get from the FTbN are more consistent. The EF needs a certain amount of fiddling, either with film speed or with the somewhat awkwardly place exposure lock button.

[mozart 2]

The Canon FTb & FTbn meter "read" the central rectangular area the center microprism. The only other camera - at the time - having a definitive metering area was the Leicaflex SL and Leicaflex SL II. Definitive area meters allow one to concentrate on the "essential" areas for exposure - thus making them ideal for unusual light situations, i.e. available light, stage photography, etc. So your Canon camera is keeping very "good company."

 

The only "possible" problem with inboard camera meters - whether definitive or not - is the fact that these meter are based upon reflected light. So one has to be careful - at least until experience is gained - as to what area to meter to give you consistent results.

 

For that reason - primarily - I long ago switched to incident light meter readings using a Gossen Luna Pro with the incident light difuser in place. The results - a much higher percentage of my 35mm slides came out correctly exposed. When I was shooting theatre photography with B & W film, I also made use of the incident light attachment because I didn't have the time to take meter readings for every shot. So I memorized the basic meter reading and then remembered whether the stage lighting went up or down a 1/2 or a full stop and then change my lens opening accordingly.

 

Hope this is useful.

 

Bill

[mozart 2]

Peter:

 

Sorry, but I forgot to add a comment.

 

Why consider a spot meter? All you have to do is to switch lenses - to a medium telephoto, for example, i.e. an 85mm or a 135mm lens - and your meter will read 12% of a smaller angle of view.

 

Again, I hope this is useful!

 

Bill