@rfusca I have a question regarding Focal Length. If a Canon lens is of type "EF", does it mean that there is no need to multiply its named FL by 1.6 to find the effective fl?
the difference is that if you'll ever get a full frame camera, you will be able to use your ef lenses. And until now, the only L lenses are in the EF lineup
on a full frame camera you will not, instead, be able to use your ef-s lenses
"To save weight and money, Nikon removed the internal focusing motor from its budget D40 and D40x DSLRs, so they will only auto-focus with newer lenses that have their own focusing motors" ------- Does "650D" has built-in focusing motor?
@rfusca great for him :) rome is rather full of tourist these days. I have a lot of fun spotting cameras around. Spotted an old Nikon slr on my bus a couple of weeks ago...
@rfusca One of the bold features of 650D is its ability to auto focus with phase-shift detection. Is such thing possible without any focusing motor neither built into the camera itself nor on the lens? Or should I buy a AF lens for this feature to work?
@meysam old micro gear motors in their cheaper lenses. USM, ultrasonic ring motors, in varying grades that is good for photography, and new STM stepper motors that is good for video
@meysam basically, what I'm saying. Is if you're wanting to use the camera for real 'film' work and not short lil' home movies - I wouldn't worry too much about AF
@Meysam yes. Then, there's the quality of the blurring (bokeh). It depends on the mechanics of the lens (number of blades, optical conformation and so on). There exist a type of lens which has a characteristic bokeh which is usually not appreciated but there is an user on photo.SE who really likes it. And I must admit that I enjoy my catadioptric lens :-)
@Meysam that tells you what will be in focus, but being out of focus slightly isn't always what you think
so, if your depth of field is say...6 inches and you're 2 feet from your background with a 35mm, the background will be out of focus, but its not going to look totally creamy
if you're doing for the really strong subject isolation like that, the 40mm probably isn't super strong at that for most situations
higher focal lengths make the background elements larger,which usually have the by product of making appear more out of focus
instead of tiny out of focus details, you've got larger out of focus areas
@meysam - take a look at these pictures. They're all at the same aperture, and the same distance from the subject to background - only focal length and distance to subject is changing. photo.blogoverflow.com/2012/05/portrait-perspective
@rfusca So I assume if the background can not get closer, there is no way to bring it in focus without changing the characteristic of lens (f/ number), right?
I have read this,so I know what an f-stop is, but what does the number on printed the lens signify?
Is this is the maximum f-stop, the ideal, or something else?
@Meysam it's called Aperture, the numbers listed are fractions so f/22 is smaller than f/8... Smaller Number = Bigger Lens Opening, Bigger Number = Smaller Lens Opening... Aperture is used to control Depth of Field. with smaller numbers (bigger lens opening) you have very narrow DOF, opposite is true with bigger numbers... So in order to get bigger DOF you need to have smaller lens opening bigger f number...
What does f-stop mean? Is it the same thing when people say "2 stops" for example?
I have read this,so I know what an f-stop is, but what does the number on printed the lens signify?
Is this is the maximum f-stop, the ideal, or something else?
What is the exposure triangle? How do the "sides" affect my photographs?
