S110 Av mode, shutter speed with forced flash

[hsinhai]

I think I am doing something really dumb, but i cant understand what.

On my S110, when using Av mode I cannot get any exposures other than 1/60 when i am in forced flash mode.

For instance if I set flash off, use F2.0; ISO800 i get 1/800 at a bright scene, and F2.0; ISO800 i get 1/40 at a darker scene.

Yet with flash on I can see images over or underexposed if i twiddle with F2.0~5.6 and ISO100~800.. no matter the exposure is always 1/60.. isn't the whole point of Av mode that the exposure will auto adjust?

Am I missing some obvious setting? otherwise how would i use Av mode with an external flash? Tv mode seems to work better/more correctly.. I would prefer to use Av mode over Tv mode so i can fix aperture.

---------- Post added May 23rd, 2014 at 11:42 AM ----------

To answer my own question. I actually understand now what is going on. 1/60 appears to be the default shutter speed for Av mode.

When you are using forced flash, the flashes TTL(?) will control the amount of power, so as you stop down the flash compensates with a larger dump. Only once it gets out of the realms of possibility for the flash to cover does the actual shutter speed change from the default.

I would prefer to be using a default of 1/125, but seems default is not configurable.


Hmm.. guess i really need to get to grips with manual.

 

[Interceptor121]

That's the way Av mode is implemented in canon cameras. There are few situations where this mode can be useful but really not many

 

[Hatul]

I think I am doing something really dumb, but i cant understand what.

On my S110, when using Av mode I cannot get any exposures other than 1/60 when i am in forced flash mode.

For instance if I set flash off, use F2.0; ISO800 i get 1/800 at a bright scene, and F2.0; ISO800 i get 1/40 at a darker scene.

Yet with flash on I can see images over or underexposed if i twiddle with F2.0~5.6 and ISO100~800.. no matter the exposure is always 1/60.. isn't the whole point of Av mode that the exposure will auto adjust?

Am I missing some obvious setting? otherwise how would i use Av mode with an external flash? Tv mode seems to work better/more correctly.. I would prefer to use Av mode over Tv mode so i can fix aperture.

---------- Post added May 23rd, 2014 at 11:42 AM ----------

To answer my own question. I actually understand now what is going on. 1/60 appears to be the default shutter speed for Av mode.

When you are using forced flash, the flashes TTL(?) will control the amount of power, so as you stop down the flash compensates with a larger dump. Only once it gets out of the realms of possibility for the flash to cover does the actual shutter speed change from the default.

I would prefer to be using a default of 1/125, but seems default is not configurable.


Hmm.. guess i really need to get to grips with manual.

I also don't like the behavior of the S cameras in Av mode. 1/60 is too slow for underwater as there is often ambient light that shows up. My old Ikelite Af35 strobe forced me to use this mode but now that I got the Z240 strobe I'm hoping no to use it.

 

[ShootingUnderwater.com]

Manual mode is best for underwater but there are a few occasions I'll use TV to control my shutter speed and let the camera worry about aperture. Change the sensitivity with ISO. I love my S95 and S100 for free diving and topside, not so much for diving.

I'm interested to know what changes you make and the outcome. Will you repost?
~R

 

[flareside]

To answer my own question. I actually understand now what is going on. 1/60 appears to be the default shutter speed for Av mode.

No, it is the default speed for flash mode. 1/60 has been the default flash sync speed in low end cameras for over 50 years now. You turn on the flash, that's where the camera goes automatically, period. That's to make sure the shutter is open when the flash happens. Which is fine if you are using the flash to light the darkness as the true shutter speed is functionally the duration of the flash (1/3000th +/- if I recall correctly), not the actual shutter speed. If you are using the flash as fill however, you are pretty much screwed by the 1/60 restriction. If you want to be relieved of this limitation, get a better camera.

If you are getting under or over exposed images, try exposure compensation.


Edit: Of course after I post this, I check my S90 and it has no problem with 1/500 flash sync in Av mode which implies Canon has seriously dumbed-down the S110.

 

[0002s]

In AV mode set you flash from 'On' to 'Slow Sync'.

 

[Interceptor121]

In AV mode set you flash from 'On' to 'Slow Sync'.

In slow sync the camera will try to get an ambient light exposure. This results in either high ISO and poor quality or slow shutter speed that end up with shake blur

It may be effective if you have a tripod otherwise the pictures that come up are far from the best (there will now be someone chipping in and saying their ISO 800 pictures are wonderful....)