[jsherman999]

Based on comments from other threads, I am not sure you would be better off with Nikon. The consensus was that Nikon glass under 50mm pretty much sucks.

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I've tried the Nikon 20 2.8 and owned both the 24 2.8 and 28 2.8, and I can confirm that yes, they do pretty much suck. I think the Nikon 18-105 kit lens is sharper at all shared apertures, for Pete's sake. Their 35mm lenses are pretty good, though.

To the OP, here's some 28mm bokeh:

S-M-C Tak 28 3.5:


Vivitar 28 2.5 wide-angle (m42):


M 28 f/2.8:


Vivitar (Komine) 28 2.8 Close Focus:

[jsherman999]

Having shot Nikon for a few prior to Pentax, I can say with assurance that the consensus you're quoting is nothing but blunt propaganda. Nikon was fine under 50mm at that time, with an impressive(affordable) 10-24mm, not to mention the 14-24 and 24/2.8 which were but a few of the reputable lenses with above average IQ. Not to mention the massive third party support as well.

So my initial statement was framed on the compromises that follow the Pentax cost of ownership in exchange for the prosumer bodies Nikon offered. And so, dropping 1200 and change for a lens in my case completely negates the objective of saving on glass with Pentax. I mean... If I'm going to drop 1200 on a lens, then I might as well get off the midrange bandwagon and reopen the prosumer doors with Nikon(ie. D700)

Whatever the case, the argument that Nikon is either lacking or inadequate under 50mm is nothing more than branding propaganda. Do a little searching and you will find that the Nikon camp was/is in very good hands in the wide angle end of things.

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With zooms, yes, and with the 35mm f/2 and new 35mm f/1.8. The older 28 1.4 is superb also, but $$$$$$.

But the AF 20, 24 and 28mm f/2.8 are not very good, and have not been updated by Nikon for a long time, because Nikon has chosen to put resources into their zooms in this range. That's good & bad, but almost every 28mm and 24mm lens I've shot in Pentax mount is a step above that Nikon 20 2.8 I borrowed and the 24 & 28 2.8's I owned.

I don't know many Nikon shooters who recommend these older wide 'consumer' primes over even the 16-85, for example, unless you are on a budget and really need the (rather soft) f/2.8 aperture.


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[Pentaxor]

OOOPS my bad. thanks for pointing it out. Should be good now.

thanks Jim, it looks like that the 2/3 stop difference doesn't give much difference in OOF rendering. personally, the bokeh rendering on the f3.5 looks better.

[stevebrot]

Having shot Nikon for a few prior to Pentax, I can say with assurance that the consensus you're quoting is nothing but blunt propaganda. Nikon was fine under 50mm at that time, with an impressive(affordable) 10-24mm, not to mention the 14-24 and 24/2.8 which were but a few of the reputable lenses with above average IQ. Not to mention the massive third party support as well.

So my initial statement was framed on the compromises that follow the Pentax cost of ownership in exchange for the prosumer bodies Nikon offered. And so, dropping 1200 and change for a lens in my case completely negates the objective of saving on glass with Pentax. I mean... If I'm going to drop 1200 on a lens, then I might as well get off the midrange bandwagon and reopen the prosumer doors with Nikon(ie. D700)

Whatever the case, the argument that Nikon is either lacking or inadequate under 50mm is nothing more than branding propaganda. Do a little searching and you will find that the Nikon camp was/is in very good hands in the wide angle end of things.

Sorry to not qualify my statement to refer to "primes". Sorry, too, that I am unaware of short focal length, low-cost, excellent Nikon primes. I considered Nikon before I bought Pentax in 2007 and rejected the big "N" at that time because I could not afford to play or pay in that space. Pentax is not a whole lot better, but when legacy glass is included in the mix, things look pretty good.

As for the $1200 figure...you may be surprised to learn that is closer to mid-range for quality optics, not high end. Anything below $800 is relatively inexpensive for quality glass purchased new in today's world.

Steve

[blende8]

People don't want to hear that but it is my view that bokeh is almost entirely dependent on the motive/scene and not the lens.
If you would shoot the same scene with different (modern) lenses of the same focal length, you will hardly see a difference.
Good/bad bokeh of a certain lens is a subjective thing and mostly a figment of your imagination.

There are a few exceptions though, e.g. lenses designed for APS-C only (= DA lenses), normally show a worse bokeh, because the circles of confusion are smaller. Also older designs, like the Heliars, show nicer bokeh, and of course the famous Minolta STF lens etc. .

[arpaagent]

People don't want to hear that but it is my view that bokeh is almost entirely dependent on the motive/scene and not the lens.
If you would shoot the same scene with different (modern) lenses of the same focal length, you will hardly see a difference.
Good/bad bokeh of a certain lens is a subjective thing and mostly a figment of your imagination.

There are a few exceptions though, e.g. lenses designed for APS-C only (= DA lenses), normally show a worse bokeh, because the circles of confusion are smaller. Also older designs, like the Heliars, show nicer bokeh, and of course the famous Minolta STF lens etc. .

I mostly disagree. To not sound to argumentative, I'll concede that for an evenly lit scene without background highlights, the OOF rendering differences between lenses may not be that noticeable....BUT...

The way that different lenses render out-of-focus highlights can be very different, most notably when used wide open (which is what I presumed the OP to be talking about...). Some lenses produce very distinct bright edges on the background highlight blur discs, while others have a more even distribution of the light over the entire disc, and even others get softer at the edges of the highlights. The lenses that have bright rings at the edges of out-of-focus highlights will generally have less pleasing bokeh, because background elements will have hard edges. The lenses with more even or smooth discs produce a much more pleasing, natural bokeh. Looking at the posts in this thread, it appears that most of these 28mm lenses have pretty harsh OOF highlights. The Takumar 28mm F3.5 seems to do the best so far wide open, but then again we are comparing F3.5 to F2.8 and below...

Anyways, all of the above doesn't really apply when shooting with the aperture closed down any. Generally, the bright halos around OOF highlights go away as soon as you step down a lens by a stop or so. Then it becomes mostly dependent on the number of aperture blades, with more aperture blades producing a rounder, more natural OOF highlight shape.

One other caveat is that this discussion matters the most when talking about OOF highlights, those little points of bright light in the background that really show the characteristics of the OOF rendering of a lens. If the scene is more evenly illuminated, without any major background highlights (or bright background lines), then you would be much more hard pressed to find any differences in bokeh.

When I chose images to post for this thread, I specifically chose photos that had relatively bright OOF highlights.

[georgweb]

Wieland/blende8, hear hear !

You are probably right in pointing at bokeh qualities dependent on the photographer as the person to choose the right (=pleasant for him/her) setting.
But, the more you know... Jay Sherman's above-posted pics are the best example what you can do if you know what you are doing and what you will get from that.

Speaking of different film or sensor formats and older lenses, "Admirable" blur samples - FM Forums
The above linked page first shows a medium format pic from a fast lens, it does look special. Scroll down to get to the last update of a clickable list of all those oldies but goodies.

My conclusion so far would be like in so many other lenstest threads:
Why in the world would you try to make a lens look ugly when it's so much more fun to make it look beautiful ?
I am positively shure the answer lies in the above-linked thread, better than any lab test.


Vivitar/Kiron 28/2 (Robin Parmar's M11) on K100D f/5.6(?)

Georg (trying to escape LBA .-)

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Last edited by georgweb; 01-06-2010 at 03:36 PM.

[stevebrot]

People don't want to hear that but it is my view that bokeh is almost entirely dependent on the motive/scene and not the lens...

I tend to agree with you. Mellow backgrounds tend to yield smooth bokeh. Busy backgrounds have the opposite affect and provide a substantial challenge to even the "smoothest" of lenses.

That being said, I have a standard set of test setups to evaluate bokeh and I can say without hesitation that it is better with some lenses. The most severe example I can give is my XR Rikenon 50/2. It is a great lens, but generates what I, in all kindness, must describe as a seriously "nervous" bokeh for certain backgrounds (grass, gravel, brush...) Nothing else in my bag does this sort of thing!



Steve

[pcarfan]

jsherman, that first image you posted to me looks like stunning bokeh.

[JohnBee]

Wieland/blende8Vivitar/Kiron 28/2

Now that's a nice 28mm bokeh!
This makes me want a D700 now

[blende8]

My conclusion so far would be like in so many other lenstest threads:
Why in the world would you try to make a lens look ugly when it's so much more fun to make it look beautiful ?

Of course!
You can make any lens look beautiful, bokehwise.
And you can make any lens look bad, bokehwise.

This forum is full of statements like "Boah, this lens has a great bokeh", when they see an image with a great bokeh.
No, what they should say is "Boah, this photographer was able to create a great bokeh".

The differences between the appearances of the circles of confusion are quite small for modern lenses.
As I said, some older designs may be a little better here, but only at the cost of other parameters.
But it's 95% scene and only 5% lens contribution to bokeh, IMO.

I do not want to say that there are no differences at all between lenses.
The strongest effect I was able to see was with some DA lenses, which have a worse bokeh compared to their full frame alternatives, due to smaller circles of confusion.

Example of differences:
DA70 - M85 - DFA100´
1. one can see the small circle of the DA70. This improves sharpness, but isn't good for bokeh.
2. one can see some chromatic aberrations with the M85. It depends on the background if this is advantageous or harmful.

[WJJ3]

...it is great to see all the pics of, and thoughts about 28mm lens bokeh! This is definitely a subjective topic, and it seems there are many factors which influence the out of focus character in photos...

I like the 28mm focal length on my Pentax DSLR because it is a 'normal' focal length. It really is different than using a normal lens on a 35mm camera, as im sure using a normal lens in medium format is, since depth of field at comparable apertures gets narrower as the format size increases...

I have been out taking more pictures with the 28/2 A lens：

[WJJ3]

BTW, these 5 photos were shot at F2. jpegs from camera set to neutral with +1 contrast, resized in photoshop...

[pcarfan]

Bokeh is subjective. To me of the 5 images posted I can live with evrything except the fourth shots which is giving me a headache....

[arpaagent]

Of course!
You can make any lens look beautiful, bokehwise.
And you can make any lens look bad, bokehwise.

This forum is full of statements like "Boah, this lens has a great bokeh", when they see an image with a great bokeh.
No, what they should say is "Boah, this photographer was able to create a great bokeh".

The differences between the appearances of the circles of confusion are quite small for modern lenses.
As I said, some older designs may be a little better here, but only at the cost of other parameters.
But it's 95% scene and only 5% lens contribution to bokeh, IMO.

I do not want to say that there are no differences at all between lenses.
The strongest effect I was able to see was with some DA lenses, which have a worse bokeh compared to their full frame alternatives, due to smaller circles of confusion.

Example of differences:
DA70 - M85 - DFA100´
1. one can see the small circle of the DA70. This improves sharpness, but isn't good for bokeh.
2. one can see some chromatic aberrations with the M85. It depends on the background if this is advantageous or harmful.

--image snipped--

Just to clarify, the format that a lens is created for does not change the size of the "circle of confusion" at all, it is solely dependent on the focal length, aperture, and distances to the focal point and the background elements. The DA 70 has smaller OOF highlights because it is a shorter focal length and also a smaller aperture. If there was an M70 F2.4 (even for FF) it would (or at least should have the same size OOF highlights in a given scene.

Now the nature of the highlights are dependent on the lens, and from looking at your examples, the DA 70 here has extremely clean OOF highlights, unlike the uneven and color-abberated OOF highlight of the M85. You've noticed this in your post, and I would pretty much guarantee that the DA 70 will produce much less "busy" bokeh under difficult situations. Now whether or not either quality is desirable is merely an opinion...