image only turn out sharper in Av mode?


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zzyzx

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Aug 25, 2007
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is it just me? i find that my image turn out sharper in Av mode than in M mode. maybe it's the incorrect way i adjust the shutter but the exposure turn out fine but not sharpness in M mode. i find that i'm more trigger happy in Av mode.

wat have i missed out?

edit: i'm using a EOS40D
 

many factors i guess.. if ur shutter too slow, definitely nt sharp if ur hands shake a lot... thus maybe it seems less sharp... another thing is that ur lens generally get sharper the smaller the aperture is... so, it could be say in Av, ur lens is at f8, whilst in M, its at 5.6...
 

is it just me? i find that my image turn out sharper in Av mode than in M mode. maybe it's the incorrect way i adjust the shutter but the exposure turn out fine but not sharpness in M mode. i find that i'm more trigger happy in Av mode.

wat have i missed out?

edit: i'm using a EOS40D

why not you try using Av mode recommended settings and input them in M mode, with the same focus point, scene, and environment. you should be able to tell where's the mystery. Probably Auto-ISO is activated in Av and not in M?
 

is it just me? i find that my image turn out sharper in Av mode than in M mode. maybe it's the incorrect way i adjust the shutter but the exposure turn out fine but not sharpness in M mode. i find that i'm more trigger happy in Av mode.

wat have i missed out?

edit: i'm using a EOS40D

Is the AV mode the exact settings as the M mode in terms of everything? Aperture, shutter speed? Are you focusing the exact same thing? Are you using manual focusing at a particular spot, or focus and compose, or auto focus? What about your metering?
 

is it just me? i find that my image turn out sharper in Av mode than in M mode. maybe it's the incorrect way i adjust the shutter but the exposure turn out fine but not sharpness in M mode. i find that i'm more trigger happy in Av mode.

wat have i missed out?

edit: i'm using a EOS40D

for people to know better what is the problem, post up pictures where the perceived problem is present.. with exif (i.e. camera info) present. then we will be better able to assist you.

otherwise, could be many factors.. anything from coincidence to technique to well, cosmic interference. of course i'm just kidding about the last point, but you knew that already.
 

many factors i guess.. if ur shutter too slow, definitely nt sharp if ur hands shake a lot... thus maybe it seems less sharp... another thing is that ur lens generally get sharper the smaller the aperture is... so, it could be say in Av, ur lens is at f8, whilst in M, its at 5.6...
This is only true to a point. Every lens has its sharpest f-stop. After you pass that f-stop you start to get image degradation due to distortion (refraction of light) at lower f-stops. This means that if you f-stop is too low or too high image quality will suffer, it is all about trade-offs. This is different from DOF which is absolutely correlated to aperture.
 

At Av mode, you are concentrating on aperture and thus D.O.F control. Objects within the D.O.F will appear sharp so I think you set a high aperture and thus have most of the frame in the D.O.F so the image tends to be "sharper". On the M and other modes though, you might not be concentrating on the aperture too much so you get less D.O.F and thus less "sharpness".

Try shooting at M, Av and Tv mode while setting the shutter speed and aperture to the same value. Barring other factors, your images should turn out the same.

Samuel
 

This is only true to a point. Every lens has its sharpest f-stop. After you pass that f-stop you start to get image degradation due to distortion (refraction of light) at lower f-stops. This means that if you f-stop is too low or too high image quality will suffer, it is all about trade-offs. This is different from DOF which is absolutely correlated to aperture.

Not entirely true. Let's assume you are on a crop camera body. The usual aperture value at which diffraction of light (not distortion - entirely different things) occurs is f/16.

A lens can have its sweet spot even as wide as f/4, but you can actually still stop down to f/8 to get more DOF, and diffraction only actually kicks in at f/16.
 

Not entirely true. Let's assume you are on a crop camera body. The usual aperture value at which diffraction of light (not distortion - entirely different things) occurs is f/16.

A lens can have its sweet spot even as wide as f/4, but you can actually still stop down to f/8 to get more DOF, and diffraction only actually kicks in at f/16.
Sorry, my bad for being vague. I didn't mean that all f-stops below the sharpest f-stop suffer from significant diffraction problems, just that as your aperture becomes extremely small you compromise the sharpness of the image due to diffraction. What I was trying to point out is that each lens has its sweet spot, but naturally you need to adjust aperture to control your DOF. :)
 

in M mode, the ISO is fixed at 400. is this a possibility? and if i stay on with Av mode, will i miss out lotsa fun with this camera?
 

in M mode, the ISO is fixed at 400. is this a possibility? and if i stay on with Av mode, will i miss out lotsa fun with this camera?

Nonsense, in M mode everything is manual, especially the ISO value. Infact, the ISO value is switchable at M, Av, Tv, and P. It is not switchable at the auto and the picture modes though.

Samuel
 

haha my bad really! in M mode, the iso is fixed at 400 IF i set it to auto ISO. now i know why i get blurer image when using M mode. cos i have been using auto ISO all the while thus the ISO is stucked at 400.

guess i have a lot to learn from you guys..
 

You dont know what you're talking about, no picture posted and you expect bona fide help. At this rate you will easily annoy tons of people.
 

haha my bad really! in M mode, the iso is fixed at 400 IF i set it to auto ISO. now i know why i get blurer image when using M mode. cos i have been using auto ISO all the while thus the ISO is stucked at 400.

guess i have a lot to learn from you guys..

...

:confused: auto ISO means your camera chooses the ISO for you.. it need not be "fixed" at 400..
 

haha my bad really! in M mode, the iso is fixed at 400 IF i set it to auto ISO. now i know why i get blurer image when using M mode. cos i have been using auto ISO all the while thus the ISO is stucked at 400.

guess i have a lot to learn from you guys..

i'm totally confused by the sentence "...in M mode, the iso is fixed at 400 IF i set it to auto ISO. "

Also ask yourself "If I set the camera to AUTO ISO, why would my camera be fixed at ISO 400??"

It seems to me like your knowledge of DSLRs has some gaps here and there, but instead of asking the right questions to fill in the blanks, you jump to the wrong conclusions and end up looking a bit silly. Read your post again.
 

haha my bad really! in M mode, the iso is fixed at 400 IF i set it to auto ISO. now i know why i get blurer image when using M mode. cos i have been using auto ISO all the while thus the ISO is stucked at 400.

guess i have a lot to learn from you guys..

your iso is not fixed at 400 if you choose auto iso lah.. why not you go out on a sunny day, choose auto for iso..take a picture and see whats the iso value?

besides, i dun think there is much image degradation for iso400 compared to iso100.

blurness and sharpness very subjective.. post a picture and its easier to diagnose your problem. you go and brush up your knowledge on shutter and aperture setting also.
 

whats to annoy or offend, its a newbies corner after all...
 

Yes i am a newbie but i certain passed my eyesight test and english. the below is a snapshot of my user manual which i delibrately downloaded from canon website. Why get annoyed? if not happy, can simply stay away from the Newbie Corner section.

This is to shut your mouth:


 

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