Stupid Question Ahead about the Canon 50mm f1.8 lens

[TechKnowBabble]

I know this is probably a VERY stupid question, but I am not familar with the lens nor any similar lenses. All my lenses are a range (28-80, 75-200 etc) I assume it being 50mm there is no zoom capability or is that incorrect. I am guessing you stand a certain distance from the subject, but the lens does autofocus slightly?

Sorry I know I must sound like an idiot.

*puts on dunce cap, sits in corner*

Nikki

[Ferdinand]

It auto focuses, just no zoom :) you will have to waltz back and forth with it to get the composition you want, but its fast and sharp for the money.

Regards,
Ferdinand

[Scottes]

With a "prime" lens like the 50mm, you have to "zoom with your feet"

Prime: Any fixed focal length lens, like 50mm f/1.8, or 100mm Macro, etc.
Zoom: Not a prime. Can change focal length, like a 70-200 L, or a 28-135mm

Had to throw that in, because the word "prime" had me for quite a while.


The 50mm f/1.8 is a great lens, good focal length, great size (small & light), sharp and crisp, and a fantastic bargain. Gotta have it. And it's a lot cheaper than L.

[TechKnowBabble]

Wonderful....thanks for the expertise..I 'thought' that's what it was. I want it for portrait photography, and convienently, I have 2 feet to move back and forth with :D

Nikki

[CoolToolGuy]

The 50 f1.8 can be bought for less than $100, and it will probably give you more bang for the buck than any other lens you can buy.

Have Fun
Rick 8)

[Cadwell]

Wonderful....thanks for the expertise..I 'thought' that's what it was. I want it for portrait photography, and convienently, I have 2 feet to move back and forth with :D

Nikki

*posts carefully in order (hopefully) to avoid re-opening a VERY large can of worms*

Umm... there are many who feel that a 50mm lens, whilst good, is not necessarily the ideal focal length for portrait photography.

There have been several in depth debates on the subject, here, and it might be useful for you to read them and form your own opinion if portrait work is your primary reason for getting the lens.

[jfretless]

50mm x 1.6 = 80mm. Pretty close to the 85mm - 100mm "ideal" portrait range.

Another note, have you researched the origins of these sayings that we use in everyday conversation. I don't want to do a google search for "bang for the buck" at work, but I do remember reading or hearing that it can be considered derogatory to women. Something to do with world war 2. Just something to consider.

John

[Scottes]

Another note, have you researched the origins of these sayings that we use in everyday conversation. I don't want to do a google search for "bang for the buck" at work, but I do remember reading or hearing that it can be considered derogatory to women. Something to do with world war 2. Just something to consider.



Bang for the buck


Meaning: Value for your money.
Example: You can buy that small fries, but the supersize gives more bang for the buck.
Origin: This phrase originates in Cold War deliberations concerning funding new weapons. For example, the US Air Force habitually claimed that ballistic missiles such as ICBM's could do more damage to an enemy country for a given expenditure than a Navy aircraft carrier could.

Thus, they claimed, missiles give more "bang for the buck" than ships.

Thanks to Melchor Balaguer and Bax

Alternatively,

The price paid to a prostitute, like most things in this world, can be negotiated, a lower price yielding more "bang for the buck".

Thanks to WFredMR

http://members.aol.com/MorelandC/HaveOriginsData.htm#BangForTheBuck


Interesting.

But I'd have to go with the Cold War version, which is always what I mean anyway.

And you could probably make anything sound dirty if you wanted to.

[Cadwell]

50mm x 1.6 = 80mm. Pretty close to the 85mm - 100mm "ideal" portrait range.



Yes, that's one way of looking at it. The other way of looking at it is that it's all to do with perspective, and that it's unchanged by the 1.6x crop factor. The theory goes that with a wide angled lens you get a "pointed" effect to the face in portraiture and that a telephoto lens "flattens" the features. The 85-100mm focal lengths are reckoned by some to be "just right".

I honestly don't know which theory is correct.

[drisley]

I read an interesting comparison of 3 canon primes, the 85mm f1.8, the 100mm f2.0, and the 135mm f2.0l.

http://www.wlcastleman.com/equip/reviews/85_100_135/index.htm

In that article, he talks about "the portrait perspective", and has a little test showing that the difference in portrait perspective between the 3 lenses is almost impossible to detect.
He posted random pictures from the 3 lenses here:
http://www.wlcastleman.com/equip/reviews/85_100_135/perspectest.htm

His results were that nobody could tell the diff between the 85mm and 100mm lenses, and even the facial perspective of the 135mm is virtually identical. The only give-away is the background blur.

"Effects are generally overshadowed by posture, angle to the camera and lighting"

Here is a shot at 85mm (I know because of the background blur)
http://www.wlcastleman.com/equip/reviews/85_100_135/ranphot/4431.jpg

Here's the shot with the 135mm (again, I can tell because of the bb).
http://www.wlcastleman.com/equip/reviews/85_100_135/ranphot/83630.jpg

I see no difference in the facial features due to focal length.

[Conor]

50mm x 1.6 = 80mm. Pretty close to the 85mm - 100mm "ideal" portrait range.

but its not a MULTIPLIER, its a CROP.

DOF doesnt not change. you Still get the 50mm DOF.

[ron chappel]

Look,lets clear this up. :x

WHEN USED AS PORTRAIT LENS the 50mm lens used on a DSLR will look exactly like an 80mm lens used on a film camera.
Same DOF.
same perspective.

IT"S BECAUSE YOU HAVE TO move back to get the same cropping/magnification

If you were doing landscapes where you are focusing near infinity it would be a very different story

[MediaMagic]

50mm x 1.6 = 80mm. Pretty close to the 85mm - 100mm "ideal" portrait range.

but its not a MULTIPLIER, its a CROP.

DOF doesnt not change. you Still get the 50mm DOF.

but its not a CROP it's a RATIO! :mrgreen:

[DAMphyne]

Ron,
If you crop the 35mm to the same size as the dslr?

[PrimoFelis]

50mm x 1.6 = 80mm. Pretty close to the 85mm - 100mm "ideal" portrait range.

but its not a MULTIPLIER, its a CROP.

DOF doesnt not change. you Still get the 50mm DOF.

Look,lets clear this up. :x

WHEN USED AS PORTRAIT LENS the 50mm lens used on a DSLR will look exactly like an 80mm lens used on a film camera.
Same DOF.
same perspective.
...

Conor and Ron,

On the DOF...

Probably this is another of those topics beaten to death multiple times in this and many other digital camera forums so I don't want to start a whole discussion all over. But I just wish to point out that the DOF does change depending on the size of sensor. (DOF increases as the sensor size decreases.)

I'm sure a Google search will turn up the DOF formula as well as a few online calculators.

(Perhaps a minor point in the context of current discussion.)

Cheers,

[PrimoFelis]

Sorry to have interrupted the ongoing discussion with a minor side issue. Please continue.

So is it a crop or a multiplier or a ratio? ???

:wink:

[MarkH]

Yes, that's one way of looking at it. The other way of looking at it is that it's all to do with perspective, and that it's unchanged by the 1.6x crop factor.

Perspective is definately changed by the crop factor. Perspective is determined by the distance from the subject, crop factor changes FoV, so using a 50mm on a 10D gives the same FoV as an 80mm on a 35mm camera. For any given photo you compose, the FoV determines the distance you need to be to compose the photo you want. i.e. With a 50mm on a 10D you stand in the same place as with an 80mm on a 35mm camera, to get the same shot - therefore they have IDENTICAL perspective.

DoF may be a little different, but with f1.8 available most find the DoF shallow enough for their tastes.

[PrimoFelis]

...
The other way of looking at it is that it's all to do with perspective, and that it's unchanged by the 1.6x crop factor.
...

Perspective is definately changed by the crop factor. Perspective is determined by the distance from the subject, crop factor changes FoV, so using a 50mm on a 10D gives the same FoV as an 80mm on a 35mm camera.
...

I think some of us might be using the word "perspective" to mean different things here.

I believe at least one common usage of the term "perspective" in photography is regarding the visual effects you observe when using lenses of different focal lengths, such that the foreground and background appears farther apart (with shorter focal length lenses) or closer together (with longer focal lengths).

For example you hear about "compression effect" one gets with a telephoto lens; this refers to an effect on this "perspective." Another term you hear is "PC (Perspective Control) lenses". These lenses allow you to control and manipulate "perspective distortion" in a photograph. One common usage of PC lenses is in architectural photography where strong perspective distortion in a photograph taken with a wide angle lens is often considered undesirable.

So in this usage of the term "perspective," it is not synonymous with "FoV" (Field of View), for instance.

And so "perspective" does NOT change with crop factor (i.e. sensor size), as stated in Cadwell's quote above.

PS. To clarify, perspective is - by definition - dependent on the focal length of lens in use. [So you can get various different "perspective" effects by shooting portraits from a same distance but by changing lens focal lengths -- switching from wide to standard to tele.]

FWIW.

[PrimoFelis]

On the second thought and re-reading MarkH's post, I think I misunderstood his point. (I now realize that it's similar to the explanation of DoF being dependent on the subject magnification and not really lens focal length.)

So... I have to think about this some more for myself; I can be quite dense sometimes. :oops: I see that MarkH may in fact be correct. But something doesn't seem right... I see why Cadwell warned that this could be a can of worm.

So, if perspective is determined by the subject distance as MarkH says, one should be able to take two identical pictures as follows:

Stand at a fixed distance from the subject. Take a picture with 28mm wide angle lens. Then Take a picture with 100mm lens. Crop both accordingly to cover the same subject area. Would the two pictures really look identical ???

I think there must be some kind of oversimplification in there somwhere.

(Sorry, just talking to myself. :lol: )

[MediaMagic]

On the second thought and re-reading MarkH's post, I think I misunderstood his point. (I now realize that it's similar to the explanation of DoF being dependent on the subject magnification and not really lens focal length.)

So... I have to think about this some more for myself; I can be quite dense sometimes. :oops: I see that MarkH may in fact be correct. I see why Cadwell warned that this could be a can of worm.

"Perspective" is an unambiguous term. It's simply " 'what you see' from your vantage point". So yes, a change in focal length without changing your distance from the subject will change "what you see" in the viewfinder and therefore your "perspective". If you change your distance from the subject, but do not change the focal length of the lens, your perspective will again change.

Okay, if you put a 50 MM on the 10D or 300D, and an 85mm on an ElanII/e your perspective, what you see in either viewfinder, will be very close to the same.

That's the easy part of the debate. The "focal length changes the facial features" debate is one I really couldn't care less about. Why? because I use whatever focal length gets me the shot I'm looking for and I've never had a subject complain about how she/he looks (at least none still living, I weed out the complainers the easy way). Seriously though, I don't think there's really an issue at all but merely that people love a good debate.

[PrimoFelis]

...
"Perspective" is an unambiguous term. It's simply " 'what you see' from your vantage point". So yes, a change in focal length without changing your distance from the subject will change "what you see" in the viewfinder and therefore your "perspective".

David, I think I understand what you are saying, and I know I could be seen as simply splitting a hair here. But I would suggest that that would be a rather incomplete (though certainly a correct) definition of the term "perspective" that misses some important points.

Here is an alternative definition courtesy of Google:

"Perspective refers to the relationship of imaged objects in a photograph. This includes their relative positions and sizes and the space between them. " (And it goes on and on.)

In the context of this portrait lens discussion, I think the key part is this "relationship of imaged objects (body parts, facial features)..." "their relative positions and sizes" in a photograph. I can see how different "perspectives" (in this sense of the word) have at least a POTENTIAL to affect the look of a subject in a portraiture.

That all said, I fully agree with you. In practice it's simple enough to try different lenses and see which results I like better. (Besides, someone already said someone else run some tests and he didn't see much of a difference.) And that's exactly why I have never given it a thought after all these years ... until now. :P Oh well, I guess at least it's a good food for thought. I promise this is my last post in this thread. :lol: (My interests include some weird/technical photographs and I thought understanding of this might somehow come in handy...)

But what I am REALLY confused about is, is it a a multiplier, or a crop, or a ratio.... :wink:

[CyberDyneSystems]

We had a post with this discussion go on for three pages or so about 5 months back.. can't remeber the name of the post.. like this one,. the titale had nothing to do with the discussion that ensued,. :roll: :wink:

Anyway,. in that case,. we ended up with jpegs of diagrams,. bar graphs and charts... :shock:

[MediaMagic]

We had a post with this discussion go on for three pages or so about 5 months back.. can't remeber the name of the post.. like this one,. the titale had nothing to do with the discussion that ensued,. :roll: :wink:

Anyway,. in that case,. we ended up with jpegs of diagrams,. bar graphs and charts... :shock:

LOL! yeah, I remember that, wasn't it one of the "What's the best portrait lens?" threads back in october or november?

[MediaMagic]

Okay, I can't resist it any longer... the will power has totally failed...

David, I think I understand what you are saying, and I know I could be seen as simply splitting a hair here. But I would suggest that that would be a rather incomplete (though certainly a correct) definition of the term "perspective" that misses some important points.

Yes, my view of photography has become more simplified. As a technogeek, it's really common for me to approach things mathematically. I was a "measurebator" to the core. Over the past few months, I've really changed the way I approach a shot. I look at a shot aestically now rather than technically. Hmmm, that's not to say I don't want a technically superior photograph, but just that beautiful shots tend to naturally be technically wonderful. That could be splitting hairs.. kind of a chicken or egg question, but I do know my shots have improved considerably since I adopted this approach.



Here is an alternative definition courtesy of Google:

"Perspective refers to the relationship of imaged objects in a photograph. This includes their relative positions and sizes and the space between them. " (And it goes on and on.)

In the context of this portrait lens discussion, I think the key part is this "relationship of imaged objects (body parts, facial features)..." "their relative positions and sizes" in a photograph. I can see how different "perspectives" (in this sense of the word) have at least a POTENTIAL to affect the look of a subject in a portraiture.



Okay, so it *IS* an ambiguous term! :lol:. Notice how I said "I couldn't care less". I didn't say you are wrong, or that I don't agree with you. Deep down under my new simplistic photographic outlook, the measurebator in me believes that you are mathematically correct. Here's the thing... A perspective is based upon a three dimentional scene with the perspective beginning at a single point. There must be a point of reference (the vantage point) otherwise the "relative positions and sizes" do not exist. Those relative positions and sizes are "what we see through the viewfinder". This three dimensional scene is then translated/flattened into two dimensions by a lens "formula". Now, to take this to the point where I agree with you... If we could take the two dimensional renditions of the same "perspective" of a scene shot with the 50mm, 85mm, etc.. and then mathematically expand them to life size, not reverse the exact formula the lens used (which would give us the exact thing with which we started), but more like take an air hose and blow them up exactly the way they are in the various photos, I believe the expansions would indeed appear slightly different at life size. The differences in appearance are infinitesimal in a photograph (unless you're contrasting a fisheye vs 85mm or something), but at life size I believe the differences of "facial alterations" would become apparent.

But, in the end, a beautiful portrait is a beautiful portrait is a beautiful portrait. Whatever works for the shot.


That all said, I fully agree with you. In practice it's simple enough to try different lenses and see which results I like better. (Besides, someone already said someone else run some tests and he didn't see much of a difference.) And that's exactly why I have never given it a thought after all these years ... until now. :P Oh well, I guess at least it's a good food for thought. I promise this is my last post in this thread. :lol: (My interests include some weird/technical photographs and I thought understanding of this might somehow come in handy...)

But what I am REALLY confused about is, is it a a multiplier, or a crop, or a ratio.... :wink:

Hey, discussing something about your craft can only be beneficial. Food for thought nourishes the mind. There may never be agreement between certain individuals, but horizons always seem to receive expansion. And to me, that's the most important thing. And since you promised that would be your last post to the thread, I don't have to worry about a rebuttal. :mrgreen:

And, Just so you know, it's a Raticropilier... :shock: