Image Stabilizer with EOS 5 - "P" Mode

Using a 28-135mm IS lens with my EOS 5 (hand held), as a new user I always use "P" mode. What possible benefit could I expect to attain, other than minimal camera shake? Does the camera's program know that it is an IS lens and hence alter the "Tv" to suit? Or should I always use a slower film?

Regards Garnet.

I'd suggest you learn to use the Av and Tv modes. Then you can take

full advantage of the IS feature.

<Does the camera's program know that it is an IS lens and hence alter

the "Tv" to suit?>

<p>

No, the camera's program does not take into consideration the fact

that you have an IS lens mounted. Follow the guidelines in the IS

lens instructions. Canon states that you can safely shoot at shutter

speeds two stops slower than the reciprocal of the focal length in

use. My experience is that this is a conservative number and even

slower shutter speeds can result in good images if you use good hand

held techniques or use a monopod.

I do believe that P mode knows and takes into consideration the focal

length being used (either fixed or "zoomed"), and it will try to set a

shutter speed that is roughly 1/the focal length in use (or faster) if

the lens can open up enough (and some EOS cameras, like the 1st Elan

model, will flash the shutter speed as a warning if it's slower than

1/ focal length) but it does not (as John said) know if IS capability

is on board. With an IS lens, try shooting in Av mode (aperture

priority) and evaluative metering, and choose the lens's maximum

aperture; by doing so, you're allowing the fastest shutter speeds to

work together with the IS fxn. Switch out of Av mode only when you

need more depth of field; switch to spot or center weighted metering

as needed.

Thank you John and Kurt for establishing that the camera program does

not recognise that an IS lens is attached. My difficulty is

comprehending how any program, that has calculated the amount of

light into the system, can adjust for two or more stops, without

utilising "exposure compensation". As I understand, the most

important feature of the IS lens is allow you to use a slow shutter

speed that would normally be prohibitive because of camera shake.

This lower Tv would allow the use of finer grain film, hence, better

images.

At this time, The way that I would achieve this, leaving DOF out

of the equation for the moment, is to load film (=< ISO100), switch

to P-mode. [incidently, IMHO, Tv and Av priority use the same program

as the P-mode, its just that one or the other is locked. The

adjusting of Tv or Av may be achieved in P-mode by moving the main

control wheel to the right or left]. I would then focus etc. and

read my Av and Tv. From the Av reading I would adjust so that it

reads approx two stops larger. I would note the Tv, which should be

slower and fire. Am I on the right track?

Do you see the day where they will have the control dial reading both

"P" and "P(IS)". Regards.....Garnet.

Whether the camera is in an auto mode or manual mode, it's brain

& light meter is still calculating (aperture) x (shutter speed) =

exposure. As far as the camera body is concerned, using (for example)

the 300/4 IS lens is no different than using the 300/4 non IS lens--if

you chose to use the latter lens with 100 ISO film, hand-held, at say,

Tv=1/30 sec. and f/4, the camera will be happy to take the shot when

you push the button, and you will likely get an unsharp photo (with

the IS lens, the photo may well be quite sharp!). With the 300/4, the

camera is not going to forbid a shutter speed slower than 1/focal

length any more than it would with the IS lens, and it is not

calculating Av x Tv = exposure any differently. THE "IS" LENS IS NOT

MAKING AN INDEPENDENT DECISION TO OPEN UP OR OVEREXPOSE THE CAMERA'S

(OR YOUR) CALCULATED EXPOSURE BY TWO (OR ANY NUMBER) OF STOPS, and so

no exposure comp. is needed. The IS lens is gyroscopically helping to

stabilize the image, but it is otherwise no different from the non IS

300/4, at least as far as the camera is concerned. Simple as that.

I own the 300/4 IS, usually coupled with the 1.4 TE (that = a

420mm/5.6 L IS lens), and I can tell you that the 2 stops slower

"rule" is vastly too conservative. I have obtained sharp images, hand

held, at speeds as slow as 1/15 sec. with 100 ISO film. 1/30 is quite

common.

Thank you Kurt for your prompt reply. I'll ponder your posting for a

while. Regards.....Garnet

It appears the claim of "an additional two stops..." is where the

confusion arises, and it is easy for some to erroniously believe that

these lenses are somehow "fast" (bigger max. aperture), when in fact

"all" one is gaining is several more "stops" of hand-holdability.

Thanks again Kurt,"The penny has droped". I understand, well

explained. Regards Garnet.