Feedback wanted: Calling all 85L owners, wish-listers, & critics

I've been conducting a poll at DPReview to gauge the interest of Nikon users in an 85mm f/1.2 lens versus the existing f/1.4 lens. I am interested to understand the views from Canon users as well. A thought crossed my mind that Canon users might actually prefer an 85L with a different maximum aperture. I'd like to know via this poll that I've set up.

Please choose 1 of the available options. I do have a minor condition: Please make your choice based on factors relevant to you, not factors you think other users would prefer instead. Feel free to share your justification in reply below. If anything is unclear about this, please post; I will try to clarify in reply.

Poe wrote in post #17870365
I've been conducting a poll at DPReview to gauge the interest of Nikon users in an 85mm f/1.2 lens versus the existing f/1.4 lens.

Maybe off topic, but do Nikon have any modern f/1.2 lenses? I thought there was an issue with the mount that meant f/1.4 is the practical limit?

Not an expert, but, I have read that several times, Canon really were forward thinking when they made that change....

No. It appears that after making some use of the optical pathway for electrical connections to operate AF and aperture functions, there's not enough space to get f/1.2 worth of light through. I've yet to have an actual optical engineer comment or find such a discussion to confirm, though.

If you have the option, why wouldn't you want the largest aperature possible? Doesn't mean you always have to use f1.2

I expected having an f/1.2 aperture and the creative possibilies that accompany it as desireable. This may not be a commonly held belief.

Poe wrote in post #17871012
I expected having an f/1.2 aperture and the creative possibilies that accompany it as desireable. This may not be a commonly held belief.

Some things to consider though:

• f/1.2 (vs f/1.4) isn't going to create massively more blur - less than the difference between f/1.8 and f/1.4: http://howmuchblur.com ….8-on-a-0.9m-wide-subject
  
• f/1.2 isn't actually going to let any more light in than f/1.4. Why? Because the angle of incidence of the light from such a wide aperture means that it doesn't "excite" the wells in a digital sensor. AFAIU Cameras fake the ISO at really wide apertures such that it looks as though you're getting more light: http://www.dxomark.com​/Reviews/F-stop-blues
  
• From what I've seen, the f/1.2 lenses (and faster) are rarely particularly sharp at f/1.2, and arguably some even seem to be compromised (to achieve that aperture), such that it isn't necessarily a case that an f/1.2 stopped down a bit is better than a slower lens wide open: http://www.the-digital-picture.com …omp=0&FLIComp=0​&APIComp=0
  

Well, the fast aperture on the 85mm f/1.2L isn't the only thing it has, with implications for background blur, and greater latitude for DOF. That particular lens has gorgeous tonal relations, it renders colors super sweet, and edges with excellent contrast. So, the optical formula also is important for utility.

sploo wrote in post #17871068
Some things to consider though:

f/1.2 (vs f/1.4) isn't going to create massively more blur - less than the difference between f/1.8 and f/1.4: http://howmuchblur.com ….8-on-a-0.9m-wide-subject

True when comparing the 2/3 f-stop change for f/1.8 to f/1.4 against the 1/3 f-stop change from f/1.4 to f/1.2. The percent change per 1/3 f-stop is increasing though.

I found the comparison of backgrounds rendered by the Nikkor 58 1.4G versus the NOCT-Nikkor f/1.2 interesting here at http://www.kenrockwell​.com/nikon/comparisons​/58mm-bokeh/

f/1.2 isn't actually going to let any more light in than f/1.4. Why? Because the angle of incidence of the light from such a wide aperture means that it doesn't "excite" the wells in a digital sensor. AFAIU Cameras fake the ISO at really wide apertures such that it looks as though you're getting more light: http://www.dxomark.com​/Reviews/F-stop-blues

The sensor may not pick up the extra light, but the lens still sends it though.

From what I've seen, the f/1.2 lenses (and faster) are rarely particularly sharp at f/1.2, and arguably some even seem to be compromised (to achieve that aperture), such that it isn't necessarily a case that an f/1.2 stopped down a bit is better than a slower lens wide open: http://www.the-digital-picture.com …omp=0&FLIComp=0​&APIComp=0

That could be. Sounds like you might like an 85 2.0L that is sharper at f/2 than the current 1.2L II is at f/2?

85LII is pretty darn sharp at F2

raksphoto wrote in post #17871094
Well, the fast aperture on the 85mm f/1.2L isn't the only thing it has, with implications for background blur, and greater latitude for DOF. That particular lens has gorgeous tonal relations, it renders colors super sweet, and edges with excellent contrast. So, the optical formula also is important for utility.

That's a very valid point. The rendering of the lens of more than just the max aperture. I don't know if there's a correlation between lenses that are f/1.2 (or faster) and any particular "look" though.

Poe wrote in post #17871104
I found the comparison of backgrounds rendered by the Nikkor 58 1.4G versus the NOCT-Nikkor f/1.2 interesting here at http://www.kenrockwell​.com/nikon/comparisons​/58mm-bokeh/

That would be more useful if the camera position were exactly the same, but unfortunately it looks as though there is some movement. There is a reasonable difference in the size of the highlights between the f/1.2 and f/1.4 though granted (obviously the rendering, onion skinning, flare etc. are all going to be very different as the lenses are from different eras).

Poe wrote in post #17871104
The sensor may not pick up the extra light, but the lens still sends it though.

Not much use to the camera (or shooter) though (unless you're shooting film)

Poe wrote in post #17871104
That could be. Sounds like you might like an 85 2.0L that is sharper at f/2 than the current 1.2L II is at f/2?

Well, I'd prefer the 50A to the 50L - though I understand 50L users often like the look it produces. I'd like an f/1.4 85A!

windpig wrote in post #17871171
85LII is pretty darn sharp at F2

Looking at other review sites and comparing 85L II results versus the Sigma 85 1.4, I'm starting to suspect the sample photos of the 85L II at TDP are out of focus.

sploo wrote in post #17871178
That would be more useful if the camera position were exactly the same, but unfortunately it looks as though there is some movement. There is a reasonable difference in the size of the highlights between the f/1.2 and f/1.4 though granted (obviously the rendering, onion skinning, flare etc. are all going to be very different as the lenses are from different eras).

I agree, the change in doll size affects the ability to compare. I prefer the 58G rendering of the bokeh. Less onion-y looking bokeh balls

Not much use to the camera (or shooter) though (unless you're shooting film)

Agreed. For digital, it could actually be working against the quality of your image due to the in-camera ISO boost.

I'd like to see an 85A from Sigma as well, particularly something that addresses LoCA and LaCA like the 85 Otus.

sploo wrote in post #17871068
Some things to consider though:

f/1.2 (vs f/1.4) isn't going to create massively more blur - less than the difference between f/1.8 and f/1.4: http://howmuchblur.com ….8-on-a-0.9m-wide-subject

I have a question about this chart to see if I'm making sense of it entirely. I made my own test setup by putting an LED about 1 meter behind the front side of a box with label on it faceing the camera. I used my 135 lens and focused on the label. I took several images at various apertures so I could create and measure the resulting blur circle of the LED in the background.

In Lightroom, I output JPEGs, normalizing the original file size to 480 pixel widths on the short axis (results in 719 px widths on the long axis). Using magic lasso tool in Photoshop to select the blur circle, I could read out the number of pixels in the selection on the histogram pane. Approximating that those pixels represent the area of a circle (rather than the n-sided polygon, n = # of aperture blades), I back-calculated the diameter (in pixel widths) from that. But when I use the chart in the above link to look up the expected diameters (converting from % of image width to pixel widths, knowing that the width of my landscape oriented photos is 719 pixel widths), I get values that are much smaller than measured, i.e. measured values are about 15X greater in value. Would you happen to have thoughts on what's driving the difference between theoretical and empirical results?

Poe wrote in post #17875325
I have a question about this chart to see if I'm making sense of it entirely. I made my own test setup by putting an LED about 1 meter behind the front side of a box with label on it faceing the camera. I used my 135 lens and focused on the label. I took several images at various apertures so I could create and measure the resulting blur circle of the LED in the background.

In Lightroom, I output JPEGs, normalizing the original file size to 480 pixel widths on the short axis (results in 719 px widths on the long axis). Using magic lasso tool in Photoshop to select the blur circle, I could read out the number of pixels in the selection on the histogram pane. Approximating that those pixels represent the area of a circle (rather than the n-sided polygon, n = # of aperture blades), I back-calculated the diameter (in pixel widths) from that. But when I use the chart in the above link to look up the expected diameters (converting from % of image width to pixel widths, knowing that the width of my landscape oriented photos is 719 pixel widths), I get values that are much smaller than measured, i.e. measured values are about 15X greater in value. Would you happen to have thoughts on what's driving the difference between theoretical and empirical results?

Good question; and one to which I don't know the answer.

I'd expect the site is using some theoretical "perfect" model (and obviously any lens isn't going to behave in the same way). Though 15x seems a long way out. For a 135 f/2 at f/2, it looks to be approx 1.7% at 1m subject-to-background distance. 15x times that means your out of focus highlights must be taking up ~25.5% of the image width; i.e. 183 pixels wide? That sounds big to me.

If you focus on the LED, how large is it in the frame? As far as I understand the blur disc is based on a point - so if the in focus highlight has any real size then it's not a single point. Effectively your whole image is made from millions of little aperture shaped discs - and only those discs on the focal plane are perfect points. In front or behind the plane they become progressively larger.

In fact, that's the whole definition of DOF; at what distance from the focal plane (for your camera settings, print size, viewing distance etc.) do the discs become visibly not points.

There might be a magnification factor I need to account for since the LED is not sufficiently far away from the subject. Below is the chart with the data I collected.