@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?

@Meysam it depends if your camera is full frame or not

since you're asking, probably it is, so you must multiply by the crop factor to get the effective field of view

probably it is NOT :-)

@Francesco It's not (650D)

for your camera, you always multiply by 1.6 to find the effective length. regardless if its ef,ef-s or anything else

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

Alright

@rfusca there's an exact duplicate of I don't know how many other questions...

@Francesco yup, A LOT

its a difficult concept cuz of the marketing

@rfusca sorry I mis-linked, I am referring to the "buying a new camera" question

@Francesco oh ya, for certain

@francesco my friend just flew into Rome yesterday btw

spending a couple weeks in italy

"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?

@Meysam doesnt need it

@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...

nikon vs canon diff

@Francesco i'm sure its most days

@Francesco nice - re: old nikon

@rfusca yes but during summer it's even more than usual

i'm very jealous of him

he's having a 'last stand' before he and the missus start cranking out kids

@rfusca yes, I was almost going to start a chat :-)

@rfusca well they will be able to come to Rome even with the kids :-)

@Francesco ya, for twice the price

@rfusca well the airplane ok, but rome is not as expensive as other places

@Francesco thats nice

i think they're only in rome for a few days, then traveling around the rest of the countryside

@rfusca they will have the trouble of choosing among many options :-)

they've got it all planned out, but ya

@Francesco its still like a 1.7k plane ticket

On a different note, I am seriously considering a CPL filter ...

@Francesco oh ya?

i have one

i never use it

@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?

but i don't do that kind of photography much

@Meysam all canon lenses have a focus motor in the lens

one of three kinds

@rfusca I'd like to try it. We have a lot of blue sky lately :-)

@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

@rfusca and USM is really nice to have, it is different

nod sure, Nikon calls it SWM and its very, very fast

@francesco but he's focusing on video - its likely a new STM motor would provide a better experience

@rfusca ah ok but apart from the pancake lens are there other choices?

not that it's not a fine choice in itself :-)

@Francesco 18-135mm

ah I didn't remember it. I have a 50D so no video for me, and I didn't give atention to those details.

always using a high quality external microphonewill eliminate much of the difference though

but the new STM are supposed to be VERY accurate on AF

ah but it's the OTHER lens which got out together with the pancake, isn't it?

yup

so far, its just those two

I wasn't looking for a zoom so I didn't study it, but now that I see it I am beginning to remember

yup'

@rfusca Is STM an equivalent of USM customized for focusing on video?

@Meysam they're two totally different technologies

STM is slower than USM

but much quieter

@rfusca aha

USM is very quiet, just not when its located 3 inches from the microphone

STM is REALLY REALLY NEW though

like a month or so

@Meysam if possible at all you should try how fast can be a good usm lens. The first time I tried it I was really surprised

@rfusca great point

@Francesco does the canon kit lens not come with USM?

@Meysam most serious videographers don't use autofocus though

@rfusca So how do they maintain focus on a moving subject (like a person walking). Do they do that by hand?

Yup, by hand

@rfusca Why? Isn't it harder?

With 'focus pulling'

@Meysam smoother

Last thing you want in a scene is for the camera to suddenly start to hunt a lil' for focus

Interesting

not to mention you use focus creatively ...you may start with something in focus and shift to something else. Harder to do with AF

easy to do manually

what they use is 'follow focus' systems

Exactly

bhphotovideo.com/c/buy/Follow-Focus-Systems/ci/12016/N/…

there are alot of DIY follow focus systems

@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

@rfusca Got it

@rfusca Is it possible to blur the background with an effective 64mm lens?

@Meysam it depends on the distance from the subject, of the subject from the background, and on the aperture of the lens

that's if I buy this

right

@Meysam can be, sure. depends on what he said

Is it possible to calculate these things? I mean any formula for that?

@Meysam in a sense, sure

dofmaster.com/dofjs.html

thats going to tell ya the effective distance that everything looks 'in focus'

Something like: with this FL and this f ratio, the background of subject at such distance can be blurred

@rfusca my kit lens didn't have usm. The 50 f/1.8 doesn't. The L lenses that I have, have it and it is different :-)

@Francesco crazy. even the nikon kit lens has it

@Meysam well there's not 'blurred and not blurred' - there's a whole range of 'barely out of focus' to 'creamy dreamy'

@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 :-)

@Francesco donut yuckiness

@rfusca it's a strange lens but it lends itself to having fun :-)

I wouldn't recommend it for a wedding ;-) but as it happens I sometimes took it out

@Francesco sure

@meysam have you read this? dpreview.com/news/2012/07/04/650dpreviewupdated

@Francesco Yes, but there is apparently no video sample yet.

@rfusca That link is really helpful. Thank you!

@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

rfusca is right, and the backgroud could be more distracting that way. So you have to learn how to do it, without focusing on the formula alone

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 Oh, let me take a look

@rfusca very clear example!

@Francesco thanks

@Meysam those are all f/5.6 i believe - so you can get creamier, but this demonstrates the focal length difference

you can do like 85mm f/2.2 and this is like probably....25 ft to the background.. spottsphoto.com/-/galleries/portfolio/-/medias/…

to give you an idea

have to go now, good night buonanotte :)

@Meysam have fun with your new camera!

@Francesco buonanotte

ciao @rfusca

ciao

@Francesco Bye, Thanks for your help :)

@Meysam you're welcome

@Francesco You guys are really kind and helpful here. Thank you :)

thats what we're here for

@rfusca It's possible to have both the subject and background in focus without using a wide lens? (using something like a 70mm lens)

(Considering the subject of your example in the blog post)

@Meysam with higher f/stop numbers

and a closer background

@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?

@Meysam when lenses are listed, they list their smallest f number - the lenses can 'stop down' to larger numbers

for example, a 50mm f/1.8 can stop down anywhere between f/1.8 and like f/16 or f/22 even

so you would need to stop the lens down to a larger number

@rfusca Ok I don't know what "stopping down the lens" means, so I should read about it.

@Meysam every lens has an adjustable iris inside called an 'aperture'

the f/number is the aperture size relative to the focal length of the lens

smaller f numbers indicate larger apertures

which mean more light

when you 'stop down' then it means that you close the aperture/iris more. this lets in less light and also brings the background more in focus

So by manually closing the aperture we can stop down to something like f/22, right? and have a more clear background

@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...

@Meysam right

but less light

so you have to compensate for less light

@rfusca Aha

either a slower shutter speed, more signal amplification (ISO), or both

@rfusca And slower shutter speeds needs a lens with VR?

@Meysam or a tripod possibly. depends on how slow

@Meysam sorry to jump into the conversation but what exactly are you trying to accomplish?

@Alen he's looking at getting a 650D for video

@rfusca Yes, that's long story short ;)

oh crap i know nothing about consumer cameras let me research

here's a great review at dpreview.com/previews/canon-eos-650d-rebel-t4i

i like to read the comments to get a real feel

@Alen lol

hey

yo

@rfusca I am off to bed. Good bye

alen i thin its more down to lens choice for him at this point The 650 is probably the best video DSLR nobody is talking about video DSLR...oh hey @Jam

video.... dslr....

@Meysam sweet dreams

odd

And thank you very much for all your help

*leaves

:)

@Meysam ciao

hey @rfus

@JamWheel lol

BUY A FREAKIN' VIDEO CAMERA!!!!11 :)

lol

@JamWheel agree

better

the problem is you can shoot damn fine video with DSLRs now though

damned video polution

@JamWheel Expensive

despite your continued struggle against it

diluting the R&D time on DSLRS... grr

remember when flicker introduced video... that was funny

Flickr*

my camera is expensive - and it has a feature I will never use on the damn thing that cost me money presumably

@JamWheel but if they're getting more sales because of video - does it even out? more cash, less time?

i vaguely recall that

@rfus maybe

lol

dinner, ciao

:D

edit wars

hey @Alen - sorry you had to witness that

it's all good homez

i'll keep it on the DL

@rfusca did you see my work on 500px what you think

link?

500px.com/alenabdula

like this one 500px.com/photo/9217283

not sure about the old lady sniffing her finger... lol

hahaha

good collection of shots in all

thanks

i really have to start shooting again, i've been off for a while

i go through patches like that

brb

shouldn't let it happen really