Why are modern 50mm lenses so damned complicated? • Hacker News Board

Re: Why are modern 50mm lenses so damned complicated?

#271

Post by Matrixik » Tue, May 11, 2021, 5:56 AM UTC

hatsunearu wrote: post #188

ajross wrote: post #24

What I don't understand isn't the design of the lenses, which are chasing ever-tightening windows of precision in a competetive market with high margins and discriminating consumers. Of course they're going to be overdesigned. What gets me is that lens distortion is a fully reversible convolution. It's not lossy, at all. Or rather, it's only lossy in the sense that the existing quantization in the sensor is already l…

>What gets me is that lens distortion is a fully reversible convolution. This is what I thought (it's not really convolution, but yes it is correctable), until I realized darktable/lensfun doesn't have lens profiles for any of my lenses... :(

If you have time and wish you can add them yourself:

https://pixls.us/articles/create-lens-calibration-data-for-l...

Re: Why are modern 50mm lenses so damned complicated?

#272

Post by lmilcin » Tue, May 11, 2021, 8:48 AM UTC

andreareina wrote: post #266

N1H1L wrote: post #258

Earlier quoted context omitted.

Did it also change air conditioning? I have been on sets thrice in my life, and everytime it has been uncomfortably hot.

In photo studio work we call the continuous (as opposed to strobe) lights hot lights for good reason. I imagine the lighting requirements for film/video isn't too much different. This was ~10 years ago though, don't know how LEDs have changed things.

LEDs help a lot. Partly because the waste less heat but also because IR spectrum is not present in LED light.

I have worked for Canal+ a long, long time ago and I have been on the set couple of times. When the studio was lit you felt hot even though there was air conditioning.

It is basically the same as meeting sunshine on a winter day with no air movement. The air is cold but the sunshine on your skin makes you feel much hotter than it really is.

Re: Why are modern 50mm lenses so damned complicated?

#273

Post by jcun4128 » Tue, May 11, 2021, 1:17 PM UTC

Zak wrote: post #247

Wowfunhappy wrote: post #235

Earlier quoted context omitted.

Huh. I’ve never owned a car or tried to buy one—I live in NYC and I never got around to getting a driver’s license. I was just under the impression cars cost many times that much at minimum.

The price floor for a barely-usable car in a US state that doesn't require an inspection to register it is probably around $500, but that can fluctuate as low as $0 (I literally watched a friend give a beat up, but driveable old van to a random construction worker in the apartment complex they were moving out of). $2000 could easily get a 15 year old Honda Civic, Toyota Corolla or similar compact car with a reputatio…

A lot of people did recommend Honda Civics, I considered it but they also apparently are at a higher risk of getting stolen too... so I didn't get one.

Re: Why are modern 50mm lenses so damned complicated?

#274

Post by jcun4128 » Tue, May 11, 2021, 1:19 PM UTC

jk7tarYZAQNpTQa wrote: post #209

jcun4128 wrote: post #134

Earlier quoted context omitted.

> GAS Haha... I was getting sucked into this, still am in a way. I spent about a year (2019) with a now cheap Sony Nex-5n with an 18-55 kit lens... but wanted to upgrade, more MP, higher video quality... got an A7II (24MP, 1080P) and then an A7RIII (42MP, 4K) ... I bought a 12-24mm F4 G lens at $1.3K __USED__ which to me is insane and that's not even that much in this space. It's just my car is $2K... I still can't c…

On contrast, I've been into photography for more than 20 years, and I currently own a Nikon D60 that was gifted to me 2 or 3 years ago (and that would cost less than $200 if I would have bought it instead). I can afford an A7IV or whatever is the latest gear, I just don't want to.

Yeah the Nex-5n with the kit lens was $140 and it was fun to shoot around with. That's what I shoot for primarily other than creating YouTube content is to go outside/be in the park, mostly doing macro since the place I live at sucks landscape wise. But yeah I shoot to have my own wallpaper and that's gotta be 4K res at least.

All my stuff is used, the latest Sony Alpha 1 is $6.5K ha a bit out of my budget.

Anyway the talk of money is bad/pointless, I saw one cinema lens that was $100K like wth... levels in life.

Re: Why are modern 50mm lenses so damned complicated?

#275

Post by hilbert42 » Tue, May 11, 2021, 1:52 PM UTC

reader_mode wrote: post #4

lmilcin wrote: post #3

I have a bunch of full frame lenses. Recently I looked at some very old ones I haven't used in a long time. I thought they are faulty (soft). After some diagnosing I found that it is not the fault of lenses but rather in the meantime I have started looking at images at 1:1 in Lightroom and gotten used to ridiculously sharp images from new cameras. Have you ever watched an old TV show and despaired how unwatchable it…

>Have you ever watched an old TV show and despaired how unwatchable it is because of low quality of image? Yes, that's the same thing -- our tastes change. I've had the opposite reaction - I'd watch something I've seen before in 4k remastered or something and it would be a worse experience because the extra details reveal the low quality tricks you can get away with on lower reproduction quality. I've even noticed po…

"and it would be a worse experience because the extra details reveal the low quality tricks you can get away with on lower reproduction quality"

I'd especially emphasize the 'tricks you can get away with' in low resolution television. A few months ago I was watching a rerun of an early 1960s B&W sitcom on a TV sub-channel running at normal 1080 HD resolution. The program was My Favorite Martian which is a spoofed up science fiction comedy series. The program features a Martian who can disappear and levitate objects so it's not unusual to see things either moving or floating in midair.

Anyway, the tricks employed to levitate things were embarrassingly obvious in standard HD/1080 resolution as it was dead easy to see that they had been suspended on nylon fishing line. When the show was first aired the most common TV standards were 405, 525 and 625 lines so the series producers were betting that the limiting resolution of these TV systems would hide the lines—which clearly they did. BTW, as a young kid I used to watch the show [on 625 B&W], and if I'd have seen that fishing line then I've made a big deal out of the fact.

Incidentally, the early series were in black & white and filmed on 35mm film which meant the original negatives would have been dazzlingly sharp in comparison to the then TV systems. It's interesting to note the present video quality of this series—unlike so many others from the time—is excellent (and that includes the later color episodes). Clearly, the recent transfer/digitization was done from negatives have been archived well. It's especially obvious in the color series which are of exceptionally good color quality given the passage of time (there's not a trace of fade, cross-coupling of color dyes or color bleed which plagues so many old films).

Re: Why are modern 50mm lenses so damned complicated?

#276

Post by xdennis » Tue, May 11, 2021, 8:37 PM UTC

pier25 wrote: post #101

dylan604 wrote: post #54

Earlier quoted context omitted.

I think 35mm->4k scans can look amazing. There's a lot going on though with film to digital scanning. The film stock itself has a lot to do with it. From the condition it has been stored as well as the actual type of film stock. The choice in a physical scanner also makes a difference. Single pass realtime captures vs slow speed triple flashed scans. Single pass is usually on a CMOS type sensor, where the triple flas…

35mm -> 4K can look amazing in terms of color, but I've yet to see a film where the added detail is not mostly film grain (exaggerated by sharpening). Do you have a good example?

But I like film grain. :) Barring exaggerated sharpening, it's closer to how it looks in a cinema film projection.

Re: Why are modern 50mm lenses so damned complicated?

#277

Post by [deleted] » Tue, May 11, 2021, 10:34 PM UTC

subhro wrote: post #146

salimmadjd wrote: post #139

Earlier quoted context omitted.

His lens tests are excellent. The lens rentals blog is the best place to find them [0]. If you're in market for high quality lenses, lens rental blog is a great resource. I also like cameralabs' lens tests [1]. Not as scientific as lensrentals, however, it has real samples and images of charts for comparison, so you can get a sense for what the different resolution means in image resolution. It also tests things beyo…

He does break down technical stuff is average Joe language. But, one this that does tick me off is his lens analysis does not consider larger formats.

[deleted]

Re: Why are modern 50mm lenses so damned complicated?

#278

Post by bscphil » Tue, May 11, 2021, 11:52 PM UTC

stormbrew wrote: post #69

NikolaNovak wrote: post #21

Earlier quoted context omitted.

Second that; Hobbit in particular seemed like a mid-budget British made-for-TV show. I get that it's all psychological, that I'm used to deliberate Hollywood motion-blur look... but I still couldn't bear it. But clearly we learned something or there was something special about Hobbit, because that hasn't necessarily been my experience with all 4k / high-frame shows or movies...

I think to a large extent people overestimated how much this feeling, specifically in the Hobbit films, came from the high frame rate vs. how much came from other artistic, creative, and budget choices they made. I saw them in both normal frame rate and HFR as they were coming out and it looked kinda low-budget, weirdly lit/color corrected, and generally just clunkier than the LotR films did in the moment.

Well said. I don't think you need to refer to HFR to explain why The Hobbit films look "fake". It's hard to imagine this clip (at 24 fps) looking any worse in HFR: https://www.youtube.com/watch?v=LCswVszTEx0

Re: Why are modern 50mm lenses so damned complicated?

#279

Post by bscphil » Wed, May 12, 2021, 12:38 AM UTC

pier25 wrote: post #12

reader_mode wrote: post #4

Earlier quoted context omitted.

>Have you ever watched an old TV show and despaired how unwatchable it is because of low quality of image? Yes, that's the same thing -- our tastes change. I've had the opposite reaction - I'd watch something I've seen before in 4k remastered or something and it would be a worse experience because the extra details reveal the low quality tricks you can get away with on lower reproduction quality. I've even noticed po…

I'm a 4K HDR fanboy, but IMO most movies shot in 35mm film should remain in 1080p. 70mm film looks great in 4K though (2001, Nolan movies, etc). It's a shame there is no 1080p HDR content. 35mm movies would benefit a lot more of higher color bit depth that higher resolution. Anyone knows if this is a codec limitation?

> 70mm film looks great in 4K though (2001, Nolan movies, etc).

Best to leave modern productions (like Nolan) out of the conversation, IMO. It can give an unrealistic picture of what resolution is achievable. Take Lawrence of Arabia for example: it's possibly the paradigmatic example of a 70mm film, and yet in most scenes the resolution is no better than an upscaled 1080p. This is due to a combination of problems: film stock degrades relatively quickly and was generally of lower quality 50+ years ago than today, and focus pulling was not precise enough to take full advantage of the available resolving power of 70mm film.

Unfortunately this is also true for many scenes in 2001: A Space Odyssey. Take a look at these comparisons here: https://caps-a-holic.com/c.php?go=1&a=0&d1=12517&d2=12509&s1... You're looking at an upscaled 1080p film versus native 4k (tonemapped to have roughly comparable colors on SDR screens). There's little if any more detail in the 4k image.

On the other hand, 35mm film certainly can have details visible only in 4k, especially more recent stuff. Check out this comparison for Casino (1995), the difference is unbelievable: https://caps-a-holic.com/c.php?d1=13389&d2=13388&s1=134076&s...

I agree with you about HDR though. It's certainly the most important improvement that's come up in the last decade, much more than the resolution increase.

> It's a shame there is no 1080p HDR content. 35mm movies would benefit a lot more of higher color bit depth that higher resolution. Anyone knows if this is a codec limitation?

Yes and no. The standard for Blu-ray (which uses H.264) is not able to accommodate HDR or 4k, so it was not possible until the release of the UHD Blu-ray standard. Players with the UHD standard support 4k, HDR, and the HEVC codec instead of H.264. HEVC (aka H.265) can support HDR at any resolution, but since you're releasing a "UHD" disc anyway that only people with supporting players can use, you may as well put it on there in 4k anyway. Better for marketing, probably. So it's a bit complicated. If you check bittorrent trackers, you'll probably be able to find 1080p films with HDR (encoded with HEVC), but no one in the industry releases films that way.

(Also, the higher bit depth is not quite as important as the extended dynamic range.)

Re: Why are modern 50mm lenses so damned complicated?

#280

Post by klodolph » Wed, May 12, 2021, 3:44 AM UTC

leemailll wrote: post #254

klodolph wrote: post #250

Earlier quoted context omitted.

As someone who sometimes shoots medium format film, sometimes shoots digital—I am a bit skeptical about claims that digital “easily beat the resolution of classical medium format film”. I shoot with a nice, but old, MF camera and prime lens on a tripod and then do wet prints (usually) or drum scans (rarely). Based on close examination of drum scans, I estimate my setup gives images of around 60-80 megapixels. Knock t…

I suspect when people compare digital against film, they often mean the 35mm film or aps size, not something like medium format or larger. Of course, there is hasselblad medium-size digital back, but it is not often seen.

The parent comment explicitly mentioned medium-format.

The point when digital became competitive with medium-format was an important milestone--it's just that if you did events, sports, wildlife, or photojournalism you were probably already on digital.