How to obtain the sharpest image possible

Just a quick simple question.

I have taken several shots with a canon d60 6 megapix DSLR.
4.0-5.6 (35-80mm)

I have found the images are not very crisp when i try do do more distant shots.
i seem to get clearer shots with my sony cybershot compact camera

If i am using f2.8 for example, the subject is very clear and background blury which is good - but when i use f22 or f18 say, the whoe picture is not as sharp as what u'd think.

am i right to expect a sharper image based on the f stop value being the highest number possible (smaller amount of light being let in)

im guessing it come down to the lens yeah

There are several factors that affect sharpness. The biggest one is the lens. Certain lenses are sharper than others. The 35-80 is not considered one of the sharper lenses. Another factor with digital sensors is diffraction. You can read all about it here. Also, P&S cameras have a lot of processing built-in to the camera whereas DSLRs allow for more user adjustment. By nature DSLR cameras do not apply as much processing and need to be adjusted in photoshop or another software.

Stop down to f/11. Put her on a tripod. Make sure she's properly focussed (AF on contrasty target, or manual focus). Use mirror lockup and delayed timer (or remote release). That is the sharpest you'll get out of the lens.

//edit: Don't stop down past f/11, you run into diffraction issues with the 1.6x crop bodies.

iv never used mirror

ill have to look into that to see how it works.

sorry - im a bit slow - when u say dont stop down past f11

u mean dont go any lower as in dont go to f2.8 or f4 ...

nope , he mean don't go past it as in f16, f22, most lenses are most sharp somewhere between f5.6-f11. you'll see quite a difference in sharpness at f11 compared to f22. if not sharp enough try f8, then f5.6, obviously length of lens makes a difference to depth of feild also

hmmm, now im kinda confused.

sorry - i know its probally simple

im doing a basic dig photg course,

and the way they present it to use is

if u want full depth of field and you want the entire frame to be sharp

then use a f stop of f18 - f22 for exapmle

i,e, landscape ...

although, if u want just a dog to be in focus and have the background blury
then use f2.8 f4 etc ....

this is right yeah

.
BUT

what your saying is kinda different

That is true with film but with digital you have diffraction. See the link in my first post for more info.

hmm. ok

i read that stuff just now and in previous days.

so, what i said above is true in theory

but what your saying as per above

is dont go much higher than f11 ...

so, even though, ud think that when your taking a landscape shot or distant shot of scenery ... in theory, your told t o use a higher f stop value (i.e f18, f22)

but dont go much past f11...

does that mean, that if i am not zoning in on a special object and i want to take a scenery shot, its ok to use from 2.8-f11

i only say that as, i thoght u'd only use a lower value f stop (i.e f.4/f2.8 if u want to blue that backdrop and focus on a subject.

Other factors affect depth of field. f/11 will yield most things in a landscape shot in focus. If you understand the factors of DOF you can obtain the shot you are looking for. Check out DOF calculators for help. For an 18mm lens on a 1.6 crop camera, like a Rebel XT, at f/11 if you focus at a distance of 6 feet your DOF is from 2.73 feet to infinity.

thanks for your advice

although, in many cases - theoreticals dont allow me to understand as well as say - visuals in front of me/alternate ways of expression

learn the theoreticals, apply them, then bend them to your own way of thinking. i've been photographing for 15 years, digital for 5, and have learnt that some situtations you just deal with with your own 'common knowledge' I've been reading some things on here that i haven't thought about in years in my photography, but have been doing in my own way, applied them as they've been written and even though they are theoretically better, they don't work for me. I think it is just a matter of learning the equipment you have and knowing how to use it to create the image you need. practise and learn from every image you take. try and grasp the theory side of it as you go, sometimes it's like "oh yeah, righto, I've got it now" as you see differences.

uncle mark,

i know what your saying.

and i certainly appreciate anyones suggestions !

i have never been an academic so sometimes all the words and mathematics of it can overwhelm me.

being creative is something that you have in you and that u can also become better at.

when it comes the the theoreticals, it takes me a lot longer for it to all sink in
and then keep it in mind when taking shots, as alot of the written stuff wont be so clear when u use it in practice.

like u said, it all takes time and everyone is differnt in the way they digest and learn and apply.

thanks "mark" and "intophotos"

so many of you guys are legends in your own right.

i kinda see so many people on here as more exciting and admirable than how people look up to celebrities.

very talented and diverse as well

You should only be at f18/22 if there's something close to the camera you also want in focus as well as the distant scenery. Otherwise, stay in the sweet f5.6~8 area.

* You've mentioned scenery/landscapes and f22, but no mention of a tripod?
It should be your most essential tool.

Some interesting points raised here.

DOF is dependent upon focal length, the aperture you use and the distance to the principal point of focus. Generally the wider open the lens, i.e. the lower numbers, the shallower the DOF so that foreground and/or background are increasingly out of focus while the subject area focussed on is sharp (we hope). DOF increases as we stop down, the higher numbers, but then you start to be concerned by where you've place the point of focus as, in theory, there is twice as much in focus beyond the focus point than there is in front.

The shorter the focal length of the lens gives a greater DOF (as well as a wider view) than a longer one if you are focussed on the same distance and at the same aperture. To complicate matters further with a zoom the DOF varies even with the same aperture as you go from the wide angle (shorter focal length) to the narrow end.

Then individual lenses have aberations that affect the sharpness too, most quality lenses tend to be at their best between two and three stops smaller apperture than when they are fully open or fully stopped down as diffraction comes into play.

Then you have the sensor that can only resolve a maximum degree of sharpness, the more pixels the higher the resolution.

Fun, isn't it?

Would like to say thanks to Mike [In2Photos] for the provided link.
Excellent tutorials on that website, well worth the visit.
Link to home page here...

http://www.cambridgein​colour.com/