Lens Hype, What is really a good lens?

[donny1963]

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..

For instance if your subject is only 1 foot away from a brick wall it's going to be more difficult to make that wall blur out of focus, it's all about depth of field of course in that matter, because if your using a small number aperture then what will be in focus that is close to your subject will decrease greatly depending on how far away it is to your subject, at 1.8 maybe 3 feel would be out of focus more so then 1 foot away.

now if your subject is 10 feet away from a bring wall behind them then it's going to be easy to put that wall out of focus, and it don't have to be a low number aperture either, you can do it with f5.6

all you have to do is have your camera very close to your subject
then your lens will have a difficult time keeping anything in focus further then 2 feet away even at aperture 5.6.

because of how close your lens is to that subject..
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.

Now the other thing people believe which is not true, is if they go out and buy a lens that can reach 1.8 aperture they will get sharp images, and they go out and get that lens and take all there pictures at f1.8 thinking this is the sharpest setting to have it on.

which is not true at all, in fact the lower number apertures are usually the softest, and not so sharp , for instance a Nikon 70-200 f2,8 using aperture 2.8 is not going to give you the sharpest pictures, in fact the sharpest area of that lens in aperture rage is f5.8 to f8.0
any lower then f5.6 the images start to get softer.. Don't believe me go to DxOMark by DxO | DxOMark and check it out for your self, i'll post a few images showing you, but i checked it out and the lowest aperture numbers are not your sharpest ranges..

Alot of people think get a 1.8 or 2.8 lens and you will get sharp images, well yes you will but not because you can use the lowest aperture numbers. don't get me wrong the Nikon 70-200 f2.8 is a very good lens, but your not getting your sharpest images at f2.8 at all..

if in a studio you take a portrait at the same focal length with the same camera and the same lens at the same distance of your subject and take a portrait shot at f2.8 and i do the same thing at the same settings only set my aperture at f7 lets say i'm going to get a much sharper image.
and Bokah isn't going to matter either in studio because if you use a nice gray or white or black backdrop you don't need to get bokah..

even in an outdoor situation you can get good bokah all you have to do is change your focal length and distance to your subject and still get a bokah at f5.6 or even f7 depending on your focal length and distance....
With portraits i tend to stay away from my lowest aperture numbers because i can get much sharper images at f5.6 and higher.. now they are situation where you might want to go to 1.8 or 2.8 if your in low light situations like a church or indoors, or at dusk yeah, but, if you can help it and want the sharpest images possible then click your aperture to f5.8 and higher and you will notice a great improvement in image quality..


NOTE: there is always a sweet spot to your aperture settings , meaning if you go too high your sharpness will decrease, meaning there is a limit to the aperture number before you start to decline in sharpness again.

alot of lenses range from f5.6 to f11 and once you get higher then that it starts to get softer again..

it's like anything else in zoom lenses your best range is normally your mid range, like barrel distortion starts at the wide end and gets better to the middle then starts to pincushion zooming in further then the mid range..
same type of thing with aperture....

NOTE: if all your looking for is good BOKAH in a portrait, then you can get that with out spending $1,000.00 + buy going out and get a 50mm F1.8 Prime, this lens is very sharp and you can get it for $100.00 or less... you can get better bokah with that lens then you would with the expensive 70-200 lens. If bokah is all you care about.

they are advantages to the 70-200 because you don't have to change your distance to your subject like yo would with the 50mm prime, , but that is the cost of convenience...

 

[480sparky]

Yet not one mention of the number and/or shape of the aperture blades.

C-.

 

[Bebulamar]

Does a good portrait have to have shallow depth of view and Bokeh?

 

[goodguy]

Does a good portrait have to have shallow depth of view and Bokeh?

Depends about what you are trying to do in picture, if you are shooting a person and the back ground is beautiful and you want to show it then you want to have background in focus, if you just want the person in the shot and see as little as possible of the background then its good to shoot open and be close to your subject.

NOTE-in my opinion 50mm lenses make shitty close head shots portraits on full frame cameras so I wouldn't recommend them, even at 70mm I still see some distortion. For me 85mm is a minimum but honestly I love a portrait at well above 100mm on my 70-200mm lens.

 

[Tim Tucker]

I think you're confusing bokeh with dof. Bokeh is a term used to describe the character of the OOF and not the limits of dof.

It is a property of lens design and nothing to do with sensors, (though dof is affected by sensor size), and certainly nothing to do with the rubbish spouted regarding the amount of light hitting the sensor, sorry.

The nature of the background including contrast and specular reflections affect it. And it is a property of lenses that has been understood since well before digital cameras (a bit past the fad stage ). See this article about the forerunner of the classic Nikkor portrait lens designed in 1949 that was specifically under-corrected for certain aberrations to create a softer bokeh:

NIKKOR - The Thousand and One Nights: Tale 45: - The superior lens hidden in the shadows of more celebrated lenses - The NIKKOR-P.C 10.5cm f/2.5 By Haruo Sato

Here is an image shot with the gauss version of that lens, a Nikkor PC 105/2.5 (1973-4), on film (way before digital ). Notice how even in strong contrast the oof in both the foreground and the background retain a very soft nature:

As for sharp images, it depend on a lot more that just aperture settings. Here's a shot I've shown before, shot handheld on my D600 at 3200iso and f2.8 with a 1966 sonner version of the Nikkor 105/2.5:

Sharp images have nothing much at all to do with aperture but rather understanding the nature of your subject, the nature of visual images, the characteristics of you lens, and a basic understanding of camera settings. Even though most of this image is actually out of focus I challenge you to produce one of f7 that appears to be sharper. Knowing what you're doing produces sharp images, not settings or technology, to be honest your point of focus is far more important.

I'd like to show you the difference in bokeh when I use my Micro-Nikkor PC 55/3.5 because that has a really choppy character to the oof. But it is so choppy that I also carry my 50/1.4 (MF) specifically because it's much better wide open than the 55/3.5. For what it's worth I found the 50/1.8D does not have a great bokeh with contrasty backgrounds and sold it a long while ago.

Sorry to be contradictory, but you present the post from a position of authority about bokeh and all you explain is the basics of dof with some misguided internet 'wisdom' regarding the properties of lenses and IQ.

 

[table1349]

50mm f1.8 Bokeh Background shot.

50mm f1.2 Bokeh Background shot.

As the song goes on Sesame Street:

One of these things is not like the other,
One of these things just doesn't belong,
Can you tell which thing is not like the other
By the time I finish my song?

If you picked the 50mm f1.2 then you would be right.

 

[Ysarex]

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

 

[Ysarex]

Yet not one mention of the number and/or shape of the aperture blades.

C-.

Can't help but think of the term deaf ears.

Joe

 

[donny1963]

I think you're confusing bokeh with dof. Bokeh is a term used to describe the character of the OOF and not the limits of dof.

It is a property of lens design and nothing to do with sensors, (though dof is affected by sensor size), and certainly nothing to do with the rubbish spouted regarding the amount of light hitting the sensor, sorry.

of course it does, that is why a full frame camera will allow you to blur the background a higher aperture numbers then a APSC camera would, because of the sensor size, larger sensor size = more light into the sensor.. that is why having lower aperture numbers blur the background better because the lens allows more light into the sensor...


APSC vs Full Frame..

As sensor size increases, the depth of field will decrease for a given aperture (when filling the frame with a subject of the same size and distance). This is because larger sensors require one to get closer to their subject, or to use a longer focal length in order to fill the frame with that subject. This means that one has to use progressively smaller aperture sizes in order to maintain the same depth of field on larger sensors. The following calculator predicts the required aperture and focal length in order to achieve the same depth of field (while maintaining perspective).

 

[donny1963]

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

of course you would get more blur in the background with full frame vs crop sensor,
if i shoot a portrait using 2.8 with APSC and you do the same thing with 2.8 with a full frame the image with the full frame will have more exposure in it (more light)

your a liar if you say different , and here bokeh is about blur in the background, here is an article about it, so i'm not the only one who says this..

Others can decide for them self what is correct.. lol

and yes sensor size effects the image differently at any aperture..



The Bokeh Effect: How Sensor Size Affects Background Blur

 

[donny1963]

Yet not one mention of the number and/or shape of the aperture blades.

C-.

Yet not one mention of the number and/or shape of the aperture blades.

C-.

Can't help but think of the term deaf ears.

Joe

I know maybe you should really listen and you would not be so miss-informed..
like i said i got proof that your wrong..
but hey don't have to let others take our words for it , they can read it for them self.

The Bokeh Effect: How Sensor Size Affects Background Blur

 

[donny1963]

Yet not one mention of the number and/or shape of the aperture blades.

C-.

Yet not one mention of the number and/or shape of the aperture blades.

C-.

Can't help but think of the term deaf ears.

Joe

how every my main point was about sharpness in given aperture settings, but i did mention full frame vs APSC when it comes to back ground..

and it's mention here by en expert here about the sensor size having a great deal to do with it as well.



time frame 11:00 of the video

 

[table1349]

Mixing Apples and Oranges will not give you Peaches.

 

[zombiesniper]

You guys are all spelling it wrong. It's bouquet and I have no idea how flowers have anything to do with my background blur.

 

[table1349]

You guys are all spelling it wrong. It's bouquet and I have no idea how flowers have anything to do with my background blur.

That is easy. If you give the wife/girlfriend a nice bouquet once in a while she may blur you background.