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 p.78 #18 · which lens has the most 3D POP? | |
nehemiahphoto wrote:
I have followed this thread on and off for some years. Have any helpful a/b controlled comparison been posted?
There were several that were posted in the original "What is 3-D" thread from 2009. Sadly, many of those have been lost to the archives / deletion / removal of images over time. One of the ones that was lost was quite interesting ... where the differences were presented ... and THEN, the "lesser" image was edited to render it more closely to match the "better" lens. The edited image was very close after skillful PP editing was applied. Granted, that was more than a decade ago, but the salient point is that the issue was well enough seen, by enough folks, that the gauntlet was thrown to see how much difference (microcontrast, etc.) could be offset in post, even if it wasn't original to the optic.
Fast forward 15 years ...
I don't have the right lenses in my current kit for doing AB controlled comparison ... meaning, mostly I don't buy many duplicate lenses that would NOT be in line with my perspectives about optical design contribution to shoot alongside those that are in line with my preferences. That would kind of be like asking someone to compare a Scotch with a Bourbon, when they're a dedicated Scotch drinker. They just wouldn't have the Bourbon around.
The AB controlled comparison would be best presented by two lenses that are significantly different in optical design, yet similar in Focal Length and aperture. If I ever pick up the VM 40/1.2 ... I'd likely do a comp of it with my 40 Cron for an AB controlled comp (as mentioned before). The 40 Cron is probably my "outlier" lens that could render f2 differently than the VM 40/1.2 would render at f2 (based on my viewing of the images posted with the VM 40/1.2
Some of my older Oly lenses (long since sold / traded) were on the "lesser" category ... and I did comps of them with my C/Y Zeiss glass, as well as my Canon glass (circa 2010). The differences were salient enough, that I moved away from my Oly glass, and migrated into the C/Y (for EF adaption) Zeiss glass. Only when I moved away from Canon (EF), did I then switch out my C/Y glass. Those were kinda tough to let go, because I had spent a bit of time finding the ones I wanted.
I digress, but if I get the right pairing to well present the difference ... I'll work up some comps. Not high on my "hurry up" radar / to do list. Reason being, I already did that for myself over a decade ago to learn what I learned about differences in optical rendering, that comes from different design approach. It was a significant investment in time and money to come to the understanding that I have, so yeah ... not in a hurry to repeat.
Just had a thought about a possible pairing ... the SL 35 Cron vs. the SL 35 Cron APO vs. M 35 Cron Pre-ASPH. Neither are in my kit, but I'd be curious how those compare, since they are all 35mm f2 and from the same mfr. Of course, there are plenty of other 35/2 lenses from other mfr's that could be in the mix. The key thing that I think most folks would want to see is to find the AB pairing that presents the most significant difference, vs. a bunch that are closely grouped together. The latter is what fuels the naysayers. Finding folks that happen to have both an SL 35 Cron APO and an M 35 Cron Pre-Asph (for example) and or the M35 KOB, to do the AB ... well, you get the gist.
To save you from going back through the thread (to find where I previously posted), here's a link (below) with Peter Karbe discussing optical design in the SL 35 Cron APO vs. 35 Summilux. At 1:24:23 ... notice the MTF charts difference. Specifically, how STEEP the rate of transition differences are. From that point, you may want to expand (earlier lead in) your viewing of Peter's explanations. Since human physiological depth cues are correlated to rate of change, the differences in toptic provide contribution to that perception (recognizing that it is a 2D medium emulating 3D perception cues, e.g. Trompe' Loeil).
Part of the reason that folks find the closer range focal distance, coupled with a faster aperture renders "3D-ish" is that the combination produces a more dramatic rate of change. As the focal distance becomes greater the rate of change decreases. As the lens is stopped down the rate of change decreases. Thus, the challenge can become finding an optic that contributes its rate of change in such degree that rates of change are retained (albeit more subtly, due to the aforementioned attributes) at "normal" or "distant" focal distances to still provide some visual depth cues. This is in part to why folks find it (more) challenging to find good cues with longer distant scenes, vs. those with "great pop" at near distance subjects (i.e. the rate of change is nuanced as the distance changes ... "visual" doppler effect-ish).
Additionally, since we know that changes in contrast (i.e. key lighting) provide for rates of change cues, also ... when faced with lower contrast lighting, lenses with slow rates of change fair less at retaining rates of change cues. Whereas, even in low contrast lighting, lenses with faster rates of change will contribute more cues, and thus provide a different level of transition cues.
Interestingly, folks rarely argue about the notion or preferences of using higher contrast lenses with lower contrast lighting / subjects and vice verse. But, as soon as one mentions the "3D" thing (which imo, is better presented as physiological response cues). some folks will come out of the woodwork, unhinged, unglued and out of their minds to decry any influence from the optic.
Ultimately ALL other factors influencing the human physiological response (lighting, distance, composition, etc.) that occur OUTSIDE the lens ... WILL PASS THROUGH the optical properties of the lens. What the lens does with that input > output varies, in its contribution to retain, enhance, or degrade the external factors, en route to the film plane. While technically "appeal to authority" may be a form of faulty logic (as a stand alone entity, in the absence of other evidential input) ... I would remind folks that Peter Karbe and other designers are no slouch in their craft, far beyond anything that those of us here have to offer. But, in the absence of Peter (et al) to personally provide what others are looking for, I refer to the video. For those who are interested, it is a long video (kinda slow at areas). The naysayers will refute anything that Peter has to offer, just as much as they refute anything offered by those here. Naysayers will say nay, sans any real effort to develop an understanding. It's just what they do.  . Folks that are truly interested in the subject might find Peter's vast knowledge about optical design interesting / intriguing. Others, not so much (which is fine, too) ... but, it is still offered to all.
There are a multitude of factors that human physiology deploy in assessing the eye / brain perceptions of depth. Some of which are outside the realm of the optical contribution (as noted previously). But, if we keep the conversation relegated to the influence of optical design A vs. optical design B ... yes, optical designs can / do have differing rates of transition, etc. And, whatever magnitude of those other attributes reside outside the lens, will still pass through the lens, for its contribution to retain, enhance or retard the cues.
Ultimately, the matter begins with a very deep understanding of how the human physiological response cues function. From that, the combination of external to the lens attributes ... coupled with internal lens attributes, influencing the optical path ... provide the culmination of physiological response cues that reach the film plane. The throughput can then be FURTHER enhanced (or degraded) in post. But, the salient point is that the lens does contribute to the total process of physiological cues, within the realm of understanding its influence on rates of change, et al.
On a personal note, I often shoot in low contrast lighting (i.e. slower transition rate) as an ambient shooter. When starting off with "lesser" visual cues, the retention of what I've got to work with and/or the enhancement of transition rates safeguards my "lesser" starting points (external). Soft, flat, diffuse lighting + slow transition optics = really slow / flat depth visual cues. Soft, flat, diffuse lighting + faster transition optic = better depth visual cues. And when shooting with lighting that provides the cues, then the amplification is also applied. Imo, where it really is differentiated isn't in the OMG, look at the WOW POP ... it's more in the NICE, even when the other factors are working against you a bit. 15 years ago, I chased the WOW POP thing. Today, I'm more interested in the retention / anti-reduction / anti-loss that the optic offers.
At the end of the day, the physiological cues are a culmination of factors that begin with the Light > Subject / Comp > Lens > Processing in the realm of process throughput to final rendering. Vary any of those stages of the process and you'll enhance / retard accordingly. In the context of this topic (optical influence), the answer remains that the lens does influence the throughput for physiological cues. It also remains that the lens is not independently, the sole influence. The naysayers lock in on. the other stages of the process to the point of disregarding the optic as meaningful. For folks that truly want to understand ... they are well advised to recognize the entirety of all stages and how they work together wrt physiological cues. That said, "a rising tide lifts all boats". So, whereas optic A is differentiated from optic B ... the influence carries through, even as the other factors vary. Albeit, it will increase / decrease in the final output accordingly. Yup, it's the entire process, which includes the variations of the optic.
YMMV
Edited on Oct 21, 2025 at 08:27 AM · View previous versions
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