Photography

One major aspect is autofocus and the motor systems needed to shift the large f-stop pieces of glass within the same housing whilst also offering silent motors, weather sealing, electronic control/communication and overall durability.

Historically and technically, primes are very simple designs, but, earlier designs could cut corners due to the formats they were designed for. I.e. b&w, 35mm, etc. These formats were nowhere near as detailed as digital images and so new elements are needed to refine the quality.

They also have a lot of patents taken up. The Leica and Zeiss patents for Summilux and Plannar, etc are very old. So rival designs often needed to take the long route to the same result.

But it all together and you have that behemoth of a Nikkor!

The Leica has 8 elements vs the Nikons 17 (!). Plus Nikon has an AF that moves two groups of elements.

I’m not a lens engineer but I think the modern “big three” primes are just totally over-engineered for crazy edge-to-edge sharpness with very low chromatic aberration, which means LOTS of lens elements. Throw in a silent AF motor and potentially image stabilization too, and you have a Quaker Oatmeal can sized lens.

I also have some vintage 50mm 1.4 the size of a shot glass which are tiny compared to modern 50mm 1.4 lenses which resemble the size of a Saturn V.

I guess the modern glass is correcting for much more optical errors people in the 70s and 80s were accepting but won't any more today. After all there wasn't 60 megapixel resolution on 35mm film (no, don't even start!).

Maybe manufacturers could have corrected these already in the 70s and 80s but the lens would have been ridiculously expensive, or big, or heavy. Or all three.

More optical groups for correcting optical aberrations.

Zeiss otus 55mm is massive for a 1.4 lens

this is a very good question.

i imagine that the physics of lenses and light play a part in this....

i wonder how much of this is a business decision?

i wanted to compare two of my better lenses.... the tiny EF-M 32 mm f/1.4 and the very big and very heavy EF 85 mm f/1.2

i put the camera on f/4 and positioned the cameras so that they had approximately the same field of view of this $100 bill. I focused in the middle of Ben Franklin's face.

i adapted the EF lens onto the M6 MkII: I wanted the same camera capturing the images. the angles of view may be slightly different. Contrast and sharpness? They look awful darn close to me.

The EF-M lens cost me a few hundred. the EF 85 cost me one or two thousand.

https://www.flickr.com/photos/73760670@N04/albums/72177720313024348/with/53362824792/

But but I adore the tiny 2.0 sigma's...

The main difference is that the newer lenses compensate for more aspects. Chromatic aberration and corner sharpness being the most obvious ones, but potentially also vignetting (there has also been a trend for new lenses to ignore vignetting with the "fix it in post"-mentality).

I don't have any experience with the Leica lens, but I've got the Canon EF-50mm 1.2 (and 1.4) and both of them are very soft in the corners wide open and they have plenty of chromatic aberrations, which is a consequence of the compact double Gauss optical formula. The Sigma Art 50mm and the RF 50mm 1.2 has a completely different level of corner sharpness and CA.

In the old days, we avoided zooms because of all the extra glass needed to do the zoom part. A perfectly good prime lens might have 4-6 pieces of glass in it. A zoom lens a dozen of more (like a modern prime). Every extra piece of glass mattered. I guess it either somehow doesn’t anymore, or the cameras are designed to compensate in away not possible with film. I don’t know and I don’t own any of these monstrosities anyway.

But, the OP’s comparison is not really valid, since you really need to compare the weight (and hypothetical size) of 4 old prime lenses to one modern one to get close to the equivalent glass.

Why are modern prime lens so big and heavy?

Simple (not really): Every time a photon passes through a medium, like say - glass - that photon gets distorted, at least to some extent. You must now correct for that distortion and you do so by... wait for it... passing it through another medium.

Uh oh. You've distorted it in an entirely new and exciting way. Which must now be corrected for. Guess how that's done?

It's enough to make an engineer weep.

Read this: https://www.dpreview.com/opinion/9236543269/why-are-modern-50mm-lenses-so-damned-complicated

Lmaoooo the Noctilux 50 1.2 is a notoriously aberration-filled lens, it doesn’t look super sharp wide open, there’s tons of coma and other issues with it. It is not a high resolution lens. The newer super primes you’re talking about are highly corrected designs that are much more optically “perfect.” They’re sharper, resolve more, and don’t have the optical aberrations that older lenses often have. Plus, the AF adapters for Leica lenses to modern mirrorless bodies will NOT give you the performance of those modern super primes. I tested one on a Sony A7R5 with a Leica lens and the performance was ludicrously bad compared to my Sony GM lenses. It’s not even close. Plus those lenses don’t perform well on Sony bodies—smeared corners, color cast issues, etc. The sensor micro lenses aren’t especially compatible.

One word. Resolution. Optical Resolution.

Compare the Leica 50mm f/2 Summicron:

​

https://preview.redd.it/ipa0zvm5za3c1.png?width=555&format=png&auto=webp&s=06621183bd2620dec5b9c9a20ad8ada836d1cb50

To the Nikkor Z 50mm f/1.8

You are specifically looking at big heavy lenses. Auto focus also adds weight and size, especially as the elements get larger.

I have 3 Voigtlander lenses for Fuji that are the smallest SLC lenses I have seen and they are quite new.

That's why Sony lenses are so impressive. Their 50 1.2 is 779g which is pretty close to the Leica Noctilux. With way better image quality and way faster af

You can say lenses, it’s alright

Because modern primes overcorrect for everything thing

Well I don't claim to know everything (or anything really) about lens design but I'll say this: Years ago they didn't try to make all these lenses as f1.2 . This is a real sore spot for me especially lens for mirrorless. They make these nice light camera bodies and try to shove a 6lb lens down my throat. I understand that ppl doing Astro work might need/want that but I'd like some lenses under 200grams to go with the body. I'm a Nikon user for over 50 years and damn near ready to ditch them as they are a particularly bad offender

Newer lenses need to somehow improve on their predecessors/competitors to make them marketable, and the trend has been on improving their optical performance (sharpness, aberrations, etc).

In the past, aberrations and lack of sharpness was embraced as "character" for lenses, or at least accepted tradeoffs for ultra-large aperture lenses. Heck, intentionally soft images were in vogue for a while. However, the current trend in the digital age has been toward edge-to-edge optical perfection wide open, with secondary consideration for things like bokeh quality, autofocus speed, handling. With that said, it has always been Leica-M's aesthetic to feature small lenses to go with their small cameras, and so they are willing to sacrifice some optical performance for that.

And finally, things likely have been helped by modern technology. I'm sure that having access to more computational power since the 70s has made it easier to create these more complex optical designs.

I guess it's something with the quality of the glass. Modern lenses are dead sharp and have very little flaring, ghosting, chromatic aberrations and low distortion. They also focus instantly with zero noise.

Say there's a short Nikon 35mm f2 which has very bad ghosting situation, and it's resolution is miles behind modern 35mm f1.8 mirrorless.

Just like any form of miniaturization, making smaller lenses requires tighter tolerances to get similar quality. Big lenses gather more light, reduce vignetting, and more easily allow for larger apertures. When you try to make these things smaller, it requires better materials, more difficult manufacturing, and more complicated engineering. Professional lenses of any brand are expensive. Leica lenses are very, very expensive in part due to these challenges.

Isn't that leica lens for rangefinder?

Did you just compare a manual lens to one with auto focus?

Read about elements that go in a lens, you'll get some idea

The Leica does not have autofocus. Adding an adapter doesn't add it either.

Hmm

Obsession with optical perfection. Engineered to have the best possible tech specs to appeal to pixel peepers. Plus, there always needs to be new stuff to sell.

Whether this actually results in better photographs is a different question.

Big and heavy means it’s better.

The Nikons have two autofocus motors.

Lenses with larger apertures ( the lower the f number the larger the aperture ) let in more light. That requires larger diameter elements. Notice the front element is larger on a 1.2 than say a 1.7. More glass/more weight.