Lens Hype, What is really a good lens?

[otherprof]

many people go out and buy an expensive lens for the wrong reasons, many will go out and buy lets say a Nikon 70-200 2.8 thinking ok they are oging to get sharp pictures and good bokah..
Bokah is a FAD people getting all hyped up thinking the only good portrait is a bokah one, meaning blur the background, but that is simply not true.

First off let me tell you the reason a background may get bokah, (blur) it has to do with many factors, not just a small number aperture like 1,8 or 2.8 it's about how close you are to your subject, and how close your subject is to the background as well, and also your focal length is if using a zoom lens and not a prime lens such as a 50mm 1.8..

First it's bokeh not bokah. Bokeh is not background blur as Tim has already noted. You're trying to write about a photographic phenomenon and you don't know what it is. The wiki definition is good: In photography, bokeh (originally /ˈboʊkɛ/,[1] /ˈboʊkeɪ/ BOH-kay — also sometimes pronounced as /ˈboʊkə/ BOH-kə,[2] Japanese: [boke]) is the aesthetic quality of the blur produced in the out-of-focus parts of an image produced by a lens. Bokeh is not the blur it's the visual character of the blur. This will help: Kiev Cameras

.....Now another factor that you need to know about Bokah , (blur) the background, is the sensor size, a full frame camera will be able to blur the background easier then using an APSC camera..

that is one of the reason that the background gets soft is because of the amount of light hitting the sensor, so if you got a full frame sensor then more light is factored in the image, rather then a APSC sensor. that is why lower aperture numbers give you a narrower depth of field, it lets more light in the image. so if you use f 3.5 on full frame sensor and use an f 3.5 on APSC sensor the full frame image is going to have more blur even at the same aperture setting.

This is incoherent nonsense. You don't get more blur from a FF sensor versus a crop sensor because the FF sensor "factors" more light in the image.

Joe

Not to be confused with "Bokar" which was a coffee sold by A&P years ago.

 

[Netskimmer]

many people go out and buy an expensive lens for the wrong reasons, many will go out and buy lets say a Nikon 70-200 2.8 thinking ok they are oging to get sharp pictures and good bokah... [continued nonsensical gibberish]

This ol'e boy's got a whole lotta stupid in him...

Got to be a troll, just trying to yank people's chains. Or a first year photography student from one of those online diploma mills that sat through a few classes and then came in here to 'school' us poor, ignorant amateurs.

 

[Tim Tucker]

I think the one point I agree with the OP on is that bokeh does tend to be a fad. It's overused by gear-heads to show off their f/1.4 lenses and showing how awesome they are shooting wide open even if the shot is poorly composed and poorly exposed.

"I shot this wide open. Woah, man, look at that bokeh! I'm an awesome photographer!"

At the end of the day it can be used as a composition device when used correctly, but shooting wide open just to get a bokeh is as cliche as a red sun over an ocean, except less perrrty.

All this is opinion of course, not fact, YMMV and all that...

Not sure I quite agree, though excessive use of very limited dof does seem to be an early phase that hopefully can be gotten over quickly (along with the glowing globes of specular reflections).

I find the way a lens renders to be quite important, and I do notice and value those with soft bokeh. Even in this thread there are examples of images shot with very narrow dof that are deliberately designed to look sharp, to fool the eye to a certain extent. It's kind of the opposite of the 'look at the oof' as they are saying more in the line of 'don't let it distract you, look at the subject'. So I find that the way certain lenses draw to be very important. It does not just apply to wide open either but affects when stopped down a couple of stops.

What I find over-rated though is the classification of bokeh on every lens as though it's a prime importance for wide open photography. It is true that there are some lenses that have a special character, and some that are quite distracting. But in the middle is a whole bunch of similar lenses who's bokeh is defined more by background choice than any special characteristic.

 

[Braineack]

I think the one point I agree with the OP on is that bokeh does tend to be a fad. It's overused by gear-heads to show off their f/1.4 lenses and showing how awesome they are shooting wide open even if the shot is poorly composed and poorly exposed.

Tell me the images this lens creates is just a fad:

The 58mm F/1.4G Thread

looking at this thread again seriously makes me wanna smash my 50mm 1.8G. The way it renders OOF area is amazing. the transitions are so smooth and pleasing forming into pillow clouds of color...ahhhhhh, i want to bathe in those clouds.

the 50mm 1.8G is harsh, nervous, and nasty in comparison. Yeah it's also a sharp lens; big whoop.

 

[Ysarex]

I think the one point I agree with the OP on is that bokeh does tend to be a fad. It's overused by gear-heads to show off their f/1.4 lenses and showing how awesome they are shooting wide open even if the shot is poorly composed and poorly exposed.

"I shot this wide open. Woah, man, look at that bokeh! I'm an awesome photographer!"

At the end of the day it can be used as a composition device when used correctly, but shooting wide open just to get a bokeh is as cliche as a red sun over an ocean, except less perrrty.

All this is opinion of course, not fact, YMMV and all that...

You seem to be making one of the same errors the OP made. Bokeh is not blur. The area in a photo that is not sharp due to DOF fall off behind and before the focus plane is not bokeh. Bokeh is the visual/aesthetic appearance of the blur but not the blur itself. This is a common misconception.

Joe

 

[unpopular]

I think you can describe bokeh in terms of subjective qualities: swirly, creamy, mushy, distracting, noisey - etc. But I don't think you can say "lens a has better bokeh than lens b". I don't think it's something that can be objectively defined like that.

There are aspects that contribute to each of these things that can be, things like chromatic aberration, coma, etc - things that accumulate into what we see as "bokeh" - but these things we knew of before some white dude misappropriated a Japanese term to mean something it doesn't in order to add mystique and false credence to a concept that was essentially fabricated.

 

[astroNikon]

bokeh ==> Bokeh hounds, do not read this thread..... Gear Porn!

 

[Solarflare]

For the record, this thread is a true horror trip. It starts by being a misnomer, since it claims to be about lens quality but really isnt, and then gets increasingly more awful after.


Depth of field (DOF) isnt very complex or hard to understand. It depends upon:

- Distance to subject/focus plane (larger distances increase DOF by square; double distance has approx 4x DOF)

- Focal length (longer focal length lowers DOF by square; double focal length has approx 1/4 DOF)

- Aperture (smaller apertures increase DOF by approx half square; one stop smaller aperture gives about 1.4x DOF)

- Sensor resolution (higher resultion/smaller pixel lower DOF in a linear way; a 12 Megapixel sensor will see 2x DOF of a 50 Megapixel sensor of same size)

See also online calculators such as Online Depth of Field Calculator


Bokeh as mentioned is the quality of the out of focus (OOF) areas. It has absolutely nothing to do with number or form of aperture blades, but depends upon the construction of the lens itself.

Ideally one wants a gaussian blurr which means the central point of an out of focus source of light has a maximum and will then decrease in intensity outside of this point. This would allow to mush the background into a pleasing pastel of colors.

(though dof is affected by sensor size),

Even if its often claimed otherwise - sensor size itself has nothing to do with DOF. Obviously a sensor can only record light - but wont manipulate it like a lens and thus wont have any influence about whats in focus and what isnt.

Sensor size instead specifies what viewing angle a certain focal length translates into. A full frame sensor ~36x24mm will require a 50mm focal length while an APS-C sensor ~24x16mm, crop factor 1.5, will require a 35mm focal length and a Micro Four Thirds sensor 17x13.3mm, crop factor 2.0, will require a 25mm focal length, all for the same viewing angle. Thus the same viewing angle with have less DOF on a larger sensor.

bokeh ==> Bokeh hounds, do not read this thread..... Gear Porn!

Um ... IMHO "gear porn" requires actually *desireable* gear ... IMHO a no-name russian lens doesnt fit that bill.

And this obsession with tons of aperture blades is illogical too. If I want a lens with a lot of Bokeh, I will probably shoot it wide open. At which point the number of blades matters ZIP. It also hasnt much influence later on.

As a general rule, I want 9 or 7 aperture blades for best sun stars. They might be rounded for lower apertures, but at f/11 and upwards they should be straight because otherwise there wont be sunstars.

 

[Braineack]

I think you can describe bokeh in terms of subjective qualities: swirly, creamy, mushy, distracting, noisey - etc. But I don't think you can say "lens a has better bokeh than lens b". I don't think it's something that can be objectively defined like that.

correct, it's subjective.

 

[thereyougo!]

I think the one point I agree with the OP on is that bokeh does tend to be a fad. It's overused by gear-heads to show off their f/1.4 lenses and showing how awesome they are shooting wide open even if the shot is poorly composed and poorly exposed.

"I shot this wide open. Woah, man, look at that bokeh! I'm an awesome photographer!"

At the end of the day it can be used as a composition device when used correctly, but shooting wide open just to get a bokeh is as cliche as a red sun over an ocean, except less perrrty.

All this is opinion of course, not fact, YMMV and all that...

You seem to be making one of the same errors the OP made. Bokeh is not blur. The area in a photo that is not sharp due to DOF fall off behind and before the focus plane is not bokeh. Bokeh is the visual/aesthetic appearance of the blur but not the blur itself. This is a common misconception.

Joe

I phrased myself poorly. I was talking about the effect. Much like other effects, it can be overused and become a cliché. Certain clichés become trendy. Much like the selective colour, it sometimes has a good look when used sparingly but can be annoying when overused.

 

[Ysarex]

For the record, this thread is a true horror trip.

Yep.

(though dof is affected by sensor size),

Even if its often claimed otherwise - sensor size itself has nothing to do with DOF. Obviously a sensor can only record light - but wont manipulate it like a lens and thus wont have any influence about whats in focus and what isnt.

Tim is correct. We've been through this before: I just learned about f-stop equivalency...

Industry standard definition of DOF and formula used to calculate DOF include sensor size as a determinant factor.

That's the standard formula for calculating hyperfocal distance. H is hyperfocal distance, f is focal length, N is f/stop and c is circle of confusion. The value for circle of confusion is calculated based on sensor size (see referenced thread).

See: Online Depth of Field Calculator
A Flexible Depth of Field Calculator
Depth of Field (DoF) calculator | PhotoPills
Tools: Canon depth-of-field calculator - Canon Professional Network

 

[robbins.photo]

 

[HughGuessWho]

NOW I remember why I stopped participating on this forum a year or so ago... nothing has changed.

 

[Tim Tucker]

(though dof is affected by sensor size),

Even if its often claimed otherwise - sensor size itself has nothing to do with DOF. Obviously a sensor can only record light - but wont manipulate it like a lens and thus wont have any influence about whats in focus and what isnt.

I agree with what you say. Except this, because you forgot to add that dof is calculated by viewing a standard 10"x 8" print so the degree of enlargement (magnification) has a direct effect as well.

 

[Braineack]

Always a Flat-Earther out there...