Has anyone noticed the following: The A-1 has the control knob for aperture marked in half stops, but for shutter speed in full stops. Therefore, the only way to control shutter speed in half stops is to use the exposure compensation wheel. BUT this wheel is marked in thirds of a stop. This looks great untill one realises that both aperture and shutter speed are controlable only in half stop intervals. Therefore, moving to (for instance) 1/3 stop, one is unsure if the settings will not change, or change half a stop; moving 2/3 stop, it is unsure if the settings will change half a stop or one stop. This effectively makes the exposure compensation dial useless for less than one stop intervals. Why did Canon do this??? Does anyone know a way round this problem?? with thanks David Bertioli

-- David Bertioli (david@cenargen.embrapa.br), September 06, 1999

Answers

I'm not sure if I have misunderstood you but then please correct me. I haven't had A-1 for about 15 years so I may remember something wrong.

> Has anyone noticed the following: The A-1 has the control knob for > aperture marked in half stops, but for shutter speed in full stops.

True. This way there are about the same amount of stops so that the same wheel can have scales for both shutter speed and aperture.

> Therefore, the only way to control shutter speed in half stops > is to use the exposure compensation wheel.

Why so? You can use Av mode and adjust aperture in half stops which will then change the shutter speed correspondingly to keep the same exposure.

Even if the camera shows the values only in half stops it adjusts them in practise without stops or at least there are much more intermediate values. The display is rounded to the nearest "standard" value. So when camera says 500 the real speed might be e.g. 1/550 or 1/460 sec.

Of course if you manually select 500 in Tv mode then the time is 1/500. It is not affected by the compensation wheel. And since there are no half stops in shutter speed selection you can't get a "permanent" 1/750 or 1/350 sec value. The only way is to let the camera select the shutter speed in Av mode and change the aperture so that you get the requested shutter speed.

regards VP

-- Vesa-Pekka (vesa-pekka.perakyla@sycon.fi), September 07, 1999.

David,

That is right, the A-1 adjusts the shutter speed and aperature without steps. So the only reason for 1/2 stop shutter speeds would be to set say 1/750. But why would you want to? If you set 1/500 in Tv mode, the camera may use an aperature of 4.6 or 4.7 or even 4.75 to get what it wants. Of course you will only see the meter reading the closest stop.

-- Terry Carraway (TCarraway@compuserve.com), September 07, 1999.

Thanks for your answers, which were helpful. I did not realise that the A-1 was not "WYSIWYG", and that in practice both shutter speed and aperture can have intermediate values. Knowing this I will begin to use the camera a bit differently. However, I think I will still miss the ability to set intermediate shutter speeds by hand. This is because I like to work in the following way much of the time.

1) Frame the shot, and choose my prefered aperture. 2) Determine the range of light intensities within the frame, and work out my best exposure. 3) set the camera completely on manual on a tripod and take the first frame 4) bracket exposure. At this point I would like to manually work in half stop sutter speeds, because I want a particular aperture. Of course I could do this with the exposure compensation wheel, but this means that I will have to work out where my exposure fits on the exposure compensation wheel compared to the cameras recommended exposure. This will take an extra step. many thanks for your answers, they will allow me to make fuller use of the camera David

-- David Bertioli (david@cenargen.embrapa.br), September 08, 1999.

Could you please clarify what you mean by "Of course I could do this with the exposure compensation wheel, but this means that I will have to work out where my exposure fits on the exposure compensation wheel compared to the cameras recommended exposure."

As far as I know the compensation wheel does not have any effect on exposure in *full manual* mode, it is the same as adjusting the ISO setting. Only the shutter speed and aperture do affect the exposure (in addition to lens and film and filters etc.).

Exposure compensating (and ISO setting) only affect the meter value. This affects the exposure only when you use auto exposure or set the shutter speed and aperture settings manually from meter values to manual controls.

But I quess you knew this already.

Then some suggestions:

1) Since you have the camera on a tripod I can't see any reason why to use full manual. You could use Av and bracket with exposure compensation wheel (1/3 steps). This way you also don't need to worry if the light intensity changes (because cloud thickness changes or so). +2/3 would always be +2/3 undependent of the shutter speed.

If you don't use a tripod then small change in framing might cause inaccuracy for the meter reading between adjacent shots.

2) If you need to bracket only 1/2 stops couldn't you just change the aperture? Is the difference in DOF really so big that you don't want to do this?

regards VP

-- Vesa-Pekka (vesa-pekka.perakyla@sycon.fi), September 09, 1999.

Correction:

Instead of saying "Since you have the camera on a tripod I can't see any reason why to use full manual." I should have said either "...I can't see any reason why you really must use full manual." or "...I can't see any reason why not to use the Av mode."

You may have your own reasons to use full manual.

VP

-- Vesa-Pekka (vesa-pekka.perakyla@sycon.fi), September 09, 1999.

Of course there is no reason why I have to use full manual, I just consider it easier. Consider the following; I am taking a photo with the sun in it. If I dont over-expose considerably compared to the camera's meter when the sun is in the frame, then most of the frame will be black. I meter on some part of the frame without the sun in it, fix the settings manually, mount the camera on the tripod, and begin to take my photos. In this sort of situation it is much more convenient to bracket by changing the manual settings than by the use of the exposure compensation wheel. This is because if I put the camera back onto semi-automatic, my "base settings" will be changed considerably, What I had determined as my manual settings may well be equivalent to the camera's semi-automatic with +2 on the exposure compensation wheel, or it may be +1.5, or 2.5. I would have to check this, and this is a bit inconvenient.

-- David Bertioli (david@cenargen.embrapa.br), September 09, 1999.

Yes, now I understand and agree as well. VP

-- VP (vesa-pekka.perakyla@sycon.fi), September 10, 1999.

I think we could agree that the design of the A-1 is certainly not a "big design fault", although it is a bit inconvenient for me to work in the way I wanted under some conditions. With the information that you gave in the answers I will be able to use the camera better. Thanks for your answers David

-- David Bertioli (david@cenargen.embrapa.br), September 10, 1999.

David, if you routinely measure the range of light intensity you might want to get the T90. It has a spot meter and a sophisticated system for making spot measurements. Also the shutter speed is adjustable in 1/2 stops.

-- Tim Brown (brownt@ase.com), September 13, 1999.

Thanks for that suggestion Tim, I was considering getting another FD body. I was somewhat put off the T90 when I heard that it is supposed to be the heaviest, noisyest and most vibration prone body Canon had ever made, although I was attracted by its fast sync speed. I was considering an F1, which can do spot readings, and, I think is supposed to be quiet and quite vibration-free, although it's fastest sync speed is 1/90. Another consideration was the cost. I wasn't too keen on investing much money in my FD system, as I know that at some stage I will have to abandon it.

-- David Bertioli (david@cenargen.embrapa.br), September 14, 1999.

David,

The T90 isn't any heavier, in fact it is lighter than my A-1 with motor drive. If nothing else it only takes 4 AA cells versus 12 for the MA Motor Drive. I do notice it being any noisier than my A-1.

The F-1 will do spot metering, but you have to find a spot metering focus screen (I have not seen one for sale recently) and you have to decide what to do after taking the spot readings.

With the T90 you can take up to 8 or 9 spot readings and the camera averages them, then you can quickly adjust the exposure in either direction with the highlight/shadow buttons. VERY nice.

I feel what you are doing is overly complex. For a backlit subject let the A-1 meter the scene, add some compensation and bracket using the compensation control. Letting the camera meter the scene I would try a compensation of 4 +/- a half and full stop. The A-1 doesn't use +2 -2 designations. 2 is ONE stop overexposed (twice the exposure) 4 is two stops over, 1/2 is one stop under and 1/4 is two stops under. And that is from what the camera actually meters, so you get the seamless shutter speed and aperature.

-- Terry Carraway (TCarraway@compuserve.com), September 29, 1999.

I use Lithium batteries in my T90 to make it lighter. The difference in weight on 12 AA batteries would be much bigger, so my suggestion is to by 12 AA Lithium batteries, and keep the A1.

It sounds like you are using the camera like a small Large camera, so a hand held spotmeter can be useful, or try a Large format camera, they start at US $300. But with filters and a bellows, you need to known what to adjust to come out right, so maybe not.

-- Xyvind Dahle (oeyvind.dahle@kvaerner.com), September 30, 1999.

My poor typing.

I meant to say that I do NOT notice my T90s being any noisier than my A-1.

FWIW I have owned an A-1 since 1981, with motor drive since 83. I recently "discovered" the T90 and now own two of them. I rarely use the A-1 these days. Not that it doesn't do a good job, it is just that the T90 does so much more.

-- Terry Carraway (TCarraway@compuserve.com), October 01, 1999.

I also have an A-1 as a second body with the A2 power winder. The A2 is smaller, lighter and slower than the motor winder, using 4 AA cells. You might want to look for one of these.

-- Tim Brown (brownt@ase.com), October 04, 1999.