50mm lens f/1.8 Bokeh

[akazoly]

What you think the 50mm lens bokeh is bad? I hear the bokeh is bad in some light condition. Is true ? Someone has a picture taken with a 50mm lens with bokeh ? Thanks!

 

[Arch]

no the bokeh isn't bad... its just not quite as good as the 1.4... but both are VERY good.

 

[akazoly]

thanks! And what mean "its just not quite as good as the 1.4" I see fuzzy disks on f/1.8 ?

 

[Arch]

The 1.4 lens is just a bit better built, and has slightly smoother bokeh but is also much more expensive.
Sorry I'm not quite with you with the 'fuzzy disks' thing?

 

[akazoly]

the left image has fuzzy disks.

BTW, why fuzzy disks appear?

 

[lextalionis]

It's because the (5 only) aperture blades are not round... http://www.the-digital-picture.com/Reviews/Canon-EF-50mm-f-1.8-II-Lens-Review.aspx

In reality there's not a whole lot of bokeh difference between the 1.4 and 1.8, but the 1.2 there is a big difference.

http://www.the-digital-picture.com/Reviews/Canon-EF-50mm-f-1.4-USM-Lens-Review.aspx

-Roy

 

[akazoly]

Sorry for question but Which is the solution to avoid fuzzy disks ?

 

[Arch]

well the background blurs more depending on things like aperture and distance from the subject. So changing these will give you different results.

 

[kobayashi]

number of aperture blades influences only the shape of spot-light sources which are out of focus, not the overall quality of bokeh. Some 8 or 9-blade lens have terrible bokeh, while some 5-blade lens have very beautiful creamy bokeh.

Zeiss is famous for a few lens with outsanding bokeh. One example:
http://www.flickr.com/photos/fodder/212873457/sizes/o/

Canon example (70-200/4):
http://www.flickr.com/photos/heathergreen/2251990085/in/pool-birdbokeh
50/1.4:
http://www.luminouslens.com/photoblog/index.php?showimage=26

My example with Canon 28-300L (focus is not on the front leaf due to myself, cause lens is very heavy and I was very tired):



zoliky: Fuzzy disks appear because strong spotlight sources are not enough out of focus, not number of aperture blades. The quality of bokeh depends more on the optics, as you can seen with wide open aperture, since aperture blades have no influence then.
To get nice fuzziness, too strong background spot-light sources should be avoided.

Nice bokeh can be obtained also with close-focus enabled lens if you put magnifying glass in front of them (in my case, 75mm 2x works best), like in these examples I made (you see that strong background spotlight even then is a problem):

 

[akazoly]

I shoot this using my 50mm lens f/1.8, I don't have macro tubes, etc.. and the bokeh is pretty good, in my opinion. The minimum focus distance for me is 0.45m, is not the best for close-up, but is enough for me. Im a student and I don't have more money to buy something better now.



The fuzzy disks not apear. This mean the focus is good ?

zoliky: Fuzzy disks appear because strong spotlight sources are not enough out of focus, not number of aperture blades.

I read the same thing in my book, but what I need to do to achieve this ? I need to set the good aperture?

 

[Battou]

Please forgive my ignorance here but, Are you refering to any particuler make and model 50mm 1.4 and 1.8 or respective apriture 50mm lenses in general?

 

[akazoly]

Sorry, I refer to 50mm f/1.8D Nikon F mount lens. I use this lens only

 

[Battou]

I was unaware of that, thank you.

The reason I asked was I currently own three diffrent 50mm lenses on the same mount from the same make:

Canon 50 mm 1.4 SSC
Canon 50 mm 1.8 SC
Canon 50 mm Macro 1:3.5

 

[kobayashi]

The fuzzy disks not apear. This mean the focus is good ?

zoliky: Fuzzy disks appear because strong spotlight sources are not enough out of focus, not number of aperture blades.

I read the same thing in my book, but what I need to do to achieve this ? I need to set the good aperture?

Fuzzy disks do not appear because there are no spotlight sources that are too strong. In cases like your photo, a green background would look much better, so if not possible, you can put some artificial background, say green paper etc.

No matter how good aperture you have, if you have too strong light in the background it won't help. It might with some filters and/or very expensive lens, but not with that 50/1.8. You can see here that even 85/1.2 (please don't search for it's price!) cannot kill background spotlights:
http://en.wikipedia.org/wiki/Image:Josefina_with_Bokeh.jpg