p.5 #2 · What exactly does a lens' "rendering" mean?
ZoneV wrote:
My personal take about rendering is, that modern lenses most time are near perfect - and therefore have a very similar rendering / signature. I do not write the same!
And because iof this, most people donīt care about rendering. They may not see differences in their images, and other images made with newer lenses.
I love the different rendering of some of my lenses. For example very striking is the soap bubble bokeh of the Meyer Trioplan 100mm f/2.8 wideopen:
As far as I know no modern lens can do this. Probably the very interessting Nikon DC lenses.
On the opposite is the Minolta / Sony STF 135mm lens, as was showed before.
I have tinkered an apodization lens to get this bokeh rendering too (Helios 44 with apodisation filter):
The 3D discussion is very tricky. I am NOT sure wheter I can see the special 3D in all images, so I can understand that many people see no special 3D effect.
With only small DOF one will not find the concept of the sometimes called "Zeiss 3D". Here one of my images with some special 3D, made at ~f/5.6 with a Zeiss 85mm f/1.4:
The 3D (if it is real) is most likely affected by microcontrast of a lens. There some lenses are better, and some are worse.
I love one of my macro lenses for its high microcontrast, but it has no iris. [on website you could open full resolution images]
Lenses with special rendering donīt need to be expensive. I bought the Meyer Trioplan 100/2.8 for under 20 Euro, nowadays it is about 170 Euro....Show more →
Excellent post! Great examples that are actually relevant to the topic.
p.5 #3 · What exactly does a lens' "rendering" mean?
Oh noes, Michael Reichmann says about mirror lenses "...their small size and comparative low cost keep them popular among some photographers, and their unique "drawing" ability [my emphasis] appeals to some."
I wonder if I have subconsciously noticed their drawing ability aside from the rendering of doughnut oof highlights...
I know, it's a serious topic. I mean no offense. Pardon me while I grab a Bokeh Burger and read on.
p.5 #7 · What exactly does a lens' "rendering" mean?
Regarding the guess-the-lens samples:
I can only talk for myself. I think most modern lenses - and a lot of old lenses too, are all very good - and very uniform. So they have very small rendering / drawing differences. Some would say they are boring, but for others they are ideal.
The Meyer Trioplan 100 can very often be identified - as long the image was taken full open with some highlight in unsharp background. This is sometimes possible with small images with 300 pixel height. Nearly the same with the Minolta Sony STF 135 lens.
Smaller differences need more image size to bee seen. I suppose sometimes one need comparison images to see the different drawing style of different lenses.
Zaitz wrote:
Excellent post! Great examples that are actually relevant to the topic.
p.5 #8 · What exactly does a lens' "rendering" mean?
Monito: What do you mean by "hyperfocal performance"?
[The hyperfocal distance is computable by using things like focal length, aperture, and distance, without reference to one particular lens model versus another.]
True. But lenses render sharply focused areas differently when the lens is used hyperfocally as compared to isolating focus on the same area. Focus a lens at infinity, and you get a different interpretation of sharp-at-infinity than if you focus short of infinity and stop down for hyperfocal performance. Different lenses handle that differently, and in direct comparisons the differences may be notable.
p.5 #9 · What exactly does a lens' "rendering" mean?
splathrop wrote:
But lenses render sharply focused areas differently when the lens is used hyperfocally as compared to isolating focus on the same area. Focus a lens at infinity, and you get a different interpretation of sharp-at-infinity than if you focus short of infinity and stop down for hyperfocal performance. Different lenses handle that differently, and in direct comparisons the differences may be notable.
Thanks for explaining. It could be called that (I'll add it to my vocabulary) though it is a package of other characteristics.
That's just bokeh plus any chromatic aberrations, a consequence of being off the subject plane of focus. Lens designers optimize the CA only for the plane of subject focus. If you don't focus at infinity, then infinity will be out of focus. How much depends on the distance to the actual focus plane and on all five other factors that influence Depth of Field.
Depth of Field is actually infinitely thin, but we think of a "depth" because we view prints and images from a distance rather than with a microscope. Thus there is a range, a depth, where the sharpness is less than the threshold where the observer considers it blurred. Depth of Field depends on distance to the subject focus plane, focal length, aperture, visual acuity of the print viewer, viewing distance to the print, and degree of enlargement (which also means that sensor size is a factor).
p.5 #10 · What exactly does a lens' "rendering" mean?
All in good fun. While it would be possible to say that I love the way the Drainpipe, 135, and 85L "render," the truth is that what I really love is the way images taken with them look. Clarity, contrast, color, pretty much regardless of aperture.
As the old Lynyrd Skynyrd song goes, "Be a simple..-..minded man."
p.5 #11 · What exactly does a lens' "rendering" mean?
splathrop wrote:
True. But lenses render sharply focused areas differently when the lens is used hyperfocally as compared to isolating focus on the same area. Focus a lens at infinity, and you get a different interpretation of sharp-at-infinity than if you focus short of infinity and stop down for hyperfocal performance. Different lenses handle that differently, and in direct comparisons the differences may be notable.
Technically, you are not "sharp at infinity" if you focus somewhere else. The (more or less) plane* of optimum focus, roughly parallel to the sensor or film, is the area that is "in focus." Areas in front of and behind this plane (if you focus closer than infinity) are out of focus. DOF is a subjective construct that essentially describes how out of focus a thing can be and still be not so OOF that you notice in some particular printing or reproduction situation.
We have a great tool for "calculating" hyperfocal distance in modern DSLRs, at least when shooting from the tripod. Use live view. Focus on your primary subject. Press the DOF preview button, zoom in to 10x magnification and look around at various parts of your composition to see if they are in focus enough for you. No calculation necessary, and you will see the outcome of your focus and aperture choices directly.
There is no "rendering" going on here at all. There is not a "different interpretation of sharp-at-infinity." To say that you "use a lens hyperfocally" is a very strange use of language, especially when coupled with "as compared to isolating focus on the same area."
This is simply how lenses focus and how sharpness diminishes when objects are not at the optimum distance. It is not magical or even all that complex. You can easily try it and see it yourself.
This is the sort of "mystification" of things that can be understood in a straightforward way that confuses and puts off a lot of folks when it comes to photography-talk.
Dan
*Yes, I know that this "surface" is not likely to be a perfectly flat one, but using the term plane here is useful and a good approximation in many cases - and field curvature is a variable that doesn't help us understand this concept.
p.5 #12 · What exactly does a lens' "rendering" mean?
outlawyer wrote:
All in good fun. While it would be possible to say that I love the way the Drainpipe, 135, and 85L "render," the truth is that what I really love is the way images taken with them look. Clarity, contrast, color, pretty much regardless of aperture.
I think you have rendered an excellent response. ;-)
p.5 #13 · What exactly does a lens' "rendering" mean?
outlawyer wrote:
All in good fun. While it would be possible to say that I love the way the Drainpipe, 135, and 85L "render," the truth is that what I really love is the way images taken with them look. Clarity, contrast, color, pretty much regardless of aperture.
As the old Lynyrd Skynyrd song goes, "Be a simple..-..minded man."
Don't think anyone has a problem with that... in that context render kind of sounds over the top...
Render might be more appropriate to describe the tractor here depending on your background and preference - great clarity, microcontrast and colours (Incidentally the picture was taken through the window of a moving train):
p.5 #14 · What exactly does a lens' "rendering" mean?
Monito wrote:
...Depth of Field is actually infinitely thin, but we think of a "depth" because we view prints and images from a distance rather than with a microscope. Thus there is a range, a depth, where the sharpness is less than the threshold where the observer considers it blurred.
More-correctly, plane of focus is thin, but depth of field is not. DoF is, by definition, the distance between the nearest and farthest objects in a scene that appear acceptably sharp.
You are correct that "acceptably sharp" will vary depending on various factors including print size, viewing distance, subject matter, etc., but depth is depth and is never "infinitely thin."
p.5 #15 · What exactly does a lens' "rendering" mean?
Photon wrote:
Oh noes, Michael Reichmann says about mirror lenses "...their small size and comparative low cost keep them popular among some photographers, and their unique "drawing" ability [my emphasis] appeals to some."
I wonder if I have subconsciously noticed their drawing ability aside from the rendering of doughnut oof highlights...
I know, it's a serious topic. I mean no offense. Pardon me while I grab a Bokeh Burger and read on.
I'm familiar with DOs and regular optics, didn't know about mirror lenses. Thanks.
p.5 #16 · What exactly does a lens' "rendering" mean?
gdanmitchell: There is no "rendering" going on here at all. There is not a "different interpretation of sharp-at-infinity." To say that you "use a lens hyperfocally" is a very strange use of language, especially when coupled with "as compared to isolating focus on the same area."
Must not have been clear. Once again, two lenses, say 100mm. Focus each on a target at 150 ft., at f/4, using out of focus areas in front and behind the target to give it visual emphasis in the image. The lenses are different designs and render the focus point differently. Lens A is notably better.
Now focus both lenses at 100 feet, using f/14, a modified hyperfocal approach to capturing your previous target. Check the appearance of the previous focal point, the one at 150 feet. Maybe you discover that doing it that way, lens B is notably bettera surprising finding, given the previous result. If so, to me, that difference is a rendering difference which becomes evident with (maybe is even dependent upon) hyperfocal use.
Maybe you are just allergic to the concept of photographic rendering. If not, why would you object to describing as a rendering difference that sort of observed difference in the performance of two lenses?
By the way, I suspect that kind of asymmetry between two lenses may be commonplace when one of them is a macro lens and the other is not.
p.5 #17 · What exactly does a lens' "rendering" mean?
gdanmitchell: I've often wondered why the French are not included in the wonderful saying about hell - to paraphrase: "Hell is where the police are German, the politicians are Italian, and the cooks are British." ;-)
"Hell is where the police are German, the politicians are Italian, and the cooks are British...and French administrators run the HR department" ;-)
p.5 #18 · What exactly does a lens' "rendering" mean?
splathrop wrote:
Must not have been clear. Once again, two lenses, say 100mm. Focus each on a target at 150 ft., at f/4, using out of focus areas in front and behind the target to give it visual emphasis in the image. The lenses are different designs and render the focus point differently. Lens A is notably better.
They cannot possibly render the focus point differently. They might render planes (surfaces, really) forward and back from it differently, but if you got the focus point right there is no bokeh there. There might be aberrations but I as I understand your idea of "rendering" you're excluding those.
Now focus both lenses at 100 feet, using f/14, a modified hyperfocal approach to capturing your previous target.
What on earth have you been reading? "Modified" how? The aperture you choose depends on the circle of confusion you choose, the "subjectiveness" that Dan refers to.
Check the appearance of the previous focal point, the one at 150 feet. Maybe you discover that doing it that way, lens B is notably bettera surprising finding, given the previous result.
Define "better". If you want the world to understand what "rendering" means, you have to do that.
P.S. "Render" and "rendering" in this usage sound vaguely ludicrous in Australian English, because we use them for what standard English calls "stucco". At least it would if I'd ever heard it.
p.5 #19 · What exactly does a lens' "rendering" mean?
melcat wrote:
They cannot possibly render the focus point differently. They might render planes (surfaces, really) forward and back from it differently, but if you got the focus point right there is no bokeh there. There might be aberrations but I as I understand your idea of "rendering" you're excluding those.
Aberrations, sharpness, microcontrast amongst other factors will impact the rendering of the focus point.
melcat wrote:
What on earth have you been reading? "Modified" how?
Apart from the aperture, the focussing point has changed.
melcat wrote:
Define "better". If you want the world to understand what "rendering" means, you have to do that.
Up to the viewer to decide that. Perhaps sharper, less aberrations, better micro contrast etc? Or exactly the opposite of these!
melcat wrote:
P.S. "Render" and "rendering" in this usage sound vaguely ludicrous in Australian English, because we use them for what standard English calls "stucco". At least it would if I'd ever heard it.
Yep, I have a "rendered" house...
I think we're over analysing this. The point is the look is dependent on lens design and setting.
, don't dash my hopes. 
