Nikkor 135mm f/2 AIS observations

wrote:
Nicholas O. Lindan wrote:
Paul Furman wrote

click for enlargement:
http://www.edgehill.net/1/?SC=go.php&DIR=California/Bay-Area/San-Francisco/neighborhoods/2007-06-19-hayes-noe&PG=1&PIC=3
I wonder how much this is exaggerated by digital versus film?

Horizontal wires are magenta, the thinner the more
magenta. Vertical wires are green.

...Look at the top of
the roof in the enlargement; it's horizontal, and has a green fringe.

Yep, and this one has green background fringing in the enlagement too:
http://www.edgehill.net/1/?SC=go.php&DIR=Southwest/2007-06-03-az/full-set/2007-06-02-midday-walk&PG=10&PIC=55


It isn't a function of distance. The second house has three vertical'ish
green wires. Below that there are and two horizontal magenta/black wires.

This is a pretty long 200mm equiv. telephoto lens with compressed
perspective. The magenta wires are OOF in the foreground coming from the
first house which is in focus, probably angling toward the lens behind
the focal plane to the next telephone pole on the block. The green wires
are angling away from the focal point. Everything behind the point of
focus is green fringed, regardless of orientation, just like the green
fringed background car in the other 50mm f/1.2 sample enlargement.

Well to me it looks like it is a function of the distance...

The effect seen is an aberration of the digital sensor and not the
lens. It may be the lens accentuates the effect in the sensor.

I've read many folks talk about CA & fringing being more obvious on
digital, usually I think because of microprisms or maybe overflow off
full wells... I don't know exactly why but it's usually more of an issue
with digital.

Try taking a picture of a horizontal/vertical grid test target and
then maybe some sense can be made of this.

The target would need to be at various distances and overexposed to show
the effect. A field of wires at various angles, test shot at various
focus points would probably help pin this down.

--
Paul Furman Photography
http://www.edgehill.net/1
Bay Natives Nursery
http://www.baynatives.com

On Jun 23, 6:01 am, Paul Furman wrote:
I've read many folks talk about CA & fringing being more obvious on
digital, usually I think because of microprisms or maybe overflow off
full wells... I don't know exactly why but it's usually more of an issue
with digital.

Maybe it also has something to do with the fact that you can now zoom
as much as you want with a single click, with no intermediate optics
(loupe, projector lens etc)?

Paul Furman wrote:
Alan Browne wrote:

Paul Furman wrote:
I recently obtained a Nikkor 135mm f/2 AIS lens. That's about 200mm
on a
D200 DSLR. Here's my observations:

1) It's great for isolating the subject with soft background. F/2 is a
lot softer than f/2.8 on my 70-200/2.8 and the bokeh is less prone to
hard edged rings with harsh background highlights. I tried doing some
tests of those two and the 105/2.8 macro... I'll have to do that more
carefully to be sure if there really is any better bokeh but there
certainly is *more* bokeh. It has a 9-bladed aperture but not rounded
edges so harsh highlights show the polygonal shape real clear even at
f/2.8 but if the background is soft enough to fade out, it looks
nice &
creamy even at f/5.6. I don't expect using it for any purpose other
than
wide open.

2) It's not very sharp, at least wide open which is the only reason
I'd
use it. That's OK for portraits & that whole soft dreamy look. Sharper
would be nicer but the new version is mucho more expensive & this
was a
fairly cheap old beater.

3) It's heavy as a tank but not terribly large: about the same bulk as
the 105/2.8 VR & considerably smaller than the 70-200/2.8 VR so less
intimidating for portraiture and quite discreet for street shooting
considering it's capabilities.

You're tempting me to get the 135mm Carl Zeiss f/1.8 for my Minolta,
er, Konica-Minolta, er, Sony, er...


I got started on this when I saw an AF 85/1.4 Nikkor available... and
missed it at a good price, then looked at the MF version but it wasn't
supposed to be that great, then noticed the new Zeiss MF 85/1.4 was
about the same price as an AF Nikkor but reviews said it wasn't really
that great for cost of no AF.

The Sony CZ is AF... which I don't care about as I hardly use AF. What
is esp. nice is that this lens is full frame.

Cheers,
Alan.

--
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-- e-meil: Remove FreeLunch.

On Jun 23, 6:01 am, Paul Furman wrote:


The target would need to be at various distances and overexposed to show
the effect. A field of wires at various angles, test shot at various
focus points would probably help pin this down.


I got bored tonight and did this for 3 of my lenses (I think thought
of something better to do ). Here's what I got:
Tamron 90mm f/2.8 macro (focused somewhere nearer than 40cm)
http://www.pbase.com/al599/image/81024075
Nikkor 28mm f/2.8 AiS (focused around 25cm, I think):
http://www.pbase.com/al599/image/81024074
18-70 zoom at 18mm:
http://www.pbase.com/image/81024210
and at 70mm:
http://www.pbase.com/al599/image/81024211
They're all at the widest f/stop at that focal length (and focus
distance, for the tamron).

I didn't try at smaller f/stops (but I know from experience that this
particular aberration decreases quickly with increasing f/stop), nor
did I try at different focus distances, nor other things. In short, it
was just a way of passing time and not at all systematic.

I nevertheless found it quite informative, and in good agreement with
my expectations for these lenses. I found the 18-70 zoom's behaviour
quite interesting (look at the 70mm result).

On Jun 24, 2:53 am, wrote:



I nevertheless found it quite informative, and in good agreement with
my expectations for these lenses. I found the 18-70 zoom's behaviour
quite interesting (look at the 70mm result).

Maybe I should have mentioned that the 18-70 was focused quite a bit
further than the other two (it doesn't focus as close anyway).

wrote:

On Jun 23, 6:01 am, Paul Furman wrote:

The target would need to be at various distances and overexposed to show
the effect. A field of wires at various angles, test shot at various
focus points would probably help pin this down.

I got bored tonight and did this for 3 of my lenses (I think thought
of something better to do ). Here's what I got:
Tamron 90mm f/2.8 macro (focused somewhere nearer than 40cm)
http://www.pbase.com/al599/image/81024075

The Tamron clearly shows green fringing in the background & purple in
the foreground like my original weird effect. That's a perfect test target.

Nikkor 28mm f/2.8 AiS (focused around 25cm, I think):
http://www.pbase.com/al599/image/81024074
18-70 zoom at 18mm:
http://www.pbase.com/image/81024210
and at 70mm:
http://www.pbase.com/al599/image/81024211
They're all at the widest f/stop at that focal length (and focus
distance, for the tamron).

I didn't try at smaller f/stops (but I know from experience that this
particular aberration decreases quickly with increasing f/stop), nor
did I try at different focus distances, nor other things. In short, it
was just a way of passing time and not at all systematic.

I nevertheless found it quite informative, and in good agreement with
my expectations for these lenses. I found the 18-70 zoom's behaviour
quite interesting (look at the 70mm result).

The 18-70 at 70 doesn't show any colors but it's only f/4.5 & maybe not
overexposed enough to show the effect. At 17mm it's got all kinds of
rainbows.

--
Paul Furman Photography
http://www.edgehill.net/1
Bay Natives Nursery
http://www.baynatives.com

On Jun 24, 3:18 am, Paul Furman wrote:

The Tamron clearly shows green fringing in the background & purple in
the foreground like my original weird effect. That's a perfect test target.

The 18-70 at 70 doesn't show any colors but it's only f/4.5 & maybe not
overexposed enough to show the effect. At 17mm it's got all kinds of
rainbows.

Make sure you're looking at these at full size (click "Original" below
the image) if you're not. They all clearly show this effect except the
zoom at 70mm. It's most visible for the Tamron and the Nikkor 28mm
(but only wide-open; if you start stopping down, it goes away in both,
but some lateral CA becomes visible in the 28mm-its only weakness,
it's spectacular otherwise).

The background doesn't have to be overexposed at all (you can check
that the fringing is visible in regions where the background is not
overexposed), just bright, otherwise you won't see the fringing
(although it's still there presumably).

It would be interesting to check some other of my lenses at various f/
stops, but I don't think I have the patience (unless tomorrow I happen
to get a few more minutes to kill and a convenient backlit target).
Anyway it depends also on the distance at which you're focused and
other things so it would take too long.