Exposure Time = Shutter Speed ?

[andreebs]

Exposure time should be equal to the shutter speed right

I found interesting fact on my 40D when shutter speed not equal to exposure time

I don't know if the 40D user experiencing the same things like mine
Anyone?
http://i280.photobucket.com/albums/kk188/indogolfers/shutterspeed-exposuretime.jpg

 

[calebk]

Hmm...I don't think any Canon camera does an in-between shutter speed like 1/64s. I'm quite aware that the 20D and 30D both don't, and I suppose the 40D doesn't either.

 

[khtee]

maybe you need to send your 40D for calibration. The 1/64 look like the actual shutter time capture by the cmos sensor. Either this cmos sensor is out of sync with the timer or your shutter maybe giving you some early sign of problems. Just send to CSC and have it check.

 

[catchlights]

when you shoot at P or A mode, with electronic shutter, the speed is not round it up as 1/60sec or 1/125sec, it can be anywhere in between when the camera think it is the ideal shutter speed,
anyway, 1/60 or 1/64 has a very little or no variation in term of exposure.

 

[catchlights]

maybe you need to send your 40D for calibration. The 1/64 look like the actual shutter time capture by the cmos sensor. Either this cmos sensor is out of sync with the timer or your shutter maybe giving you some early sign of problems. Just send to CSC and have it check.

best advice I even seen. :bsmilie: :bsmilie: :bsmilie:

 

[TonyF]

I have the same thing on my 40d with my images where the shutter speed and exposure time are different.

Appers on 'Exposure Program' that is Aperature Priority, Manual, Portrait, Normal (i assume this is Auto), Landscape. Pbly does it in every other mode as well ... but these just happen to be images i looked at.

Has been hapenning on my second ever image taken with the camera (it's about 6-7 weeks old), right up to the today.. Not sure if it was on the first image... cos that was deleted

BTW... I've also noticed that the on some of the images.. the Lens Aperature and F-Number don't always match up.

Tony

 

[alternatve]

That would be the camera using stepless shutter speeds, ie shutter speeds not linked to the normal shutter speeds we're used to. Quite a nifty thing indeed. Soon it'll be apertures that would be stepless, current models still have "steps".

Samuel

 

[TonyF]

That would be the camera using stepless shutter speeds, ie shutter speeds not linked to the normal shutter speeds we're used to. Quite a nifty thing indeed. Soon it'll be apertures that would be stepless, current models still have "steps".

Samuel

I thought the fact that i get F/5.7 for Lens Aperature (F-Number is F/5.6) would imply aperature is stepless? Or is it stepped but in really small increments?

Also why, in manual mode, if we tell the camera we want f/5.6 (and that it allows the user to change in increments of 1/3 of a stop) would it decide that it should be f/5.7?

Sorry, I'm quite new to photography, so I may not understand exactly what is going on :embrass:

Cheers,
Tony

 

[andreebs]

Let me try to get explanation from CSC or Canon Indonesia.

for the time being I also post this symptoms on dpreview.com forum.

Thanks for the comment & will keep you updated.

 

[EiRiK]

maybe they just round it off to the nearest number?
coz i know even ISO is not exactly as stated, eg. sensitivity of ISO100 may actually be 125, something like that

 

[calebk]

maybe they just round it off to the nearest number?
coz i know even ISO is not exactly as stated, eg. sensitivity of ISO100 may actually be 125, something like that

Wherever did you get that?

ISO 125 is +1/3EV from ISO 100. +1/3EV translates to 1/3 f/stop exposure difference, definitely not a marginal error.

What EXIF viewer are you guys using? If it's purely through windows, I wouldn't trust it; instead I would go with something photographer-specific, like Opanda for Windows, or Phoenix Slides for Mac.

 

[TonyF]

OK... tried Opanda IEXIF viewer.... it show the Exposure Time as 2.5s.... and the Shutter Speed Value (which i'm assuming is where windows is pulling Shutter Speed from) of -1.38 TV... any idea what this means? (file properties report the Shutter Speed of this image as being 2.59s)

On another image that has matching Shutter Speed and Exposure Time, but an F-Number of f/5.6 and Lens Aperture of f/5.7 (under file Properties) i get an F Number of 5.6 and an Aperture Value of 5 AV.

No idea what the values in Aperture Value and Shutter Speed mean (and couldn't find any help with the application or anything of any use on their website :S)

Tony

 

[Doughnuts]

Is there a reset to factory defaults button on the cam? could be your timings could be restored via reset.

 

[alternatve]

I thought the fact that i get F/5.7 for Lens Aperature (F-Number is F/5.6) would imply aperature is stepless? Or is it stepped but in really small increments?

Also why, in manual mode, if we tell the camera we want f/5.6 (and that it allows the user to change in increments of 1/3 of a stop) would it decide that it should be f/5.7?

Sorry, I'm quite new to photography, so I may not understand exactly what is going on :embrass:

Cheers,
Tony

In manual mode, what you set is what the camera will use, hence the term manual. Only in P and the automatic modes will the camera do as it wishes and in P mode you have program shift. In Av mode, you choose a fixed aperture and the shutter speed is left to the camera to decide. Vice versa for Tv mode.

Samuel

 

[EiRiK]

Wherever did you get that?

ISO 125 is +1/3EV from ISO 100. +1/3EV translates to 1/3 f/stop exposure difference, definitely not a marginal error.

What EXIF viewer are you guys using? If it's purely through windows, I wouldn't trust it; instead I would go with something photographer-specific, like Opanda for Windows, or Phoenix Slides for Mac.

i feel happy to teach ppl something
http://www.dpreview.com/reviews/CanonEOS30D/page20.asp

 

[charlesleong]

i think all that page does is show that sensitivity of canon systems is slightly higher than Nikon (by about 1/3 stop), it does not show that 100=125.

 

[EiRiK]

i think all that page does is show that sensitivity of canon systems is slightly higher than Nikon (by about 1/3 stop), it does not show that 100=125.

for 30d it does

 

[charlesleong]

it's calibrated differently. you're using a different scale completely.

when i shoot your 30D at ISO100, the EXIF reads 100. when i shoot it at 125, it reads 125.

Unless when you shoot at 100, the EXIF reads 125?

 

[hazmee]

So what's the prob here? Are your pictures blurry? Not sharp? Overexposed?

 

[zjun]

I came across this thread while trying to find out an answer on the shutter speed/exposure time difference.

I set a 1/40 shutter speed and took a shot.
the EXIF data shows 1/41 for Shutter Speed and 1/40 for Exposure Time.

I did another at 1/4000
the EXIF data shows 1/4098 for Shutter Speed and 1/4000 for Exposure Time.

wondering why? I'm using the 450D.

Anyone could have an answer? I tried asking CSC too but it was said that it's a question never encountered before. hmm. :dunno: