Wide open?

[davela]

The best lens I've used wide-open lately has been the Nikon 50mm F1.2 AIS version - simply phenomenal. I assume a Leica Noctilux is better, but I'll never be able to afford one. The Canon 50mm F1.2 is usable wide open, but nothing to write home about (fine lens overall however). The CV 50/1.1 has a pretty good rep wide open or otherwise.

 

[RalphLambrecht]

i've yet to seer a 35mm lens that doesn' pperform it's best at f8-11.

 

[keithwms]

i've yet to seer a 35mm lens that doesn' pperform it's best at f8-11.

Oh I'd be willing to bet a matted print that the contax g lenses are at their best a few stops wider than that.

But anyway I have yet to see a photograph for which any of this matters.

 

[keithwms]

P.S. Ah-Ha! Contax G 45/2 has better MTF at f/4 than at f/8. Not really a surprise to those of us who've beheld one.

http://www.photodo.com/lens/Contax-G-Planar-45mm-f2-783

I'd expect the same of the konica hexar AF 35 and the comparable Leica and Zeiss lenses.

 

[Aristophanes]

While in principle I agree that that all optical design is a tradeoff, I disagree with your implication that that means that there are no fast lenses out there with great all-round performance.

Using the same Nikkor 35mm f/2.0 AIS as an example, while a fine lens in its own right, I have 35mm lenses which:
1) are sharper wide open
2) vignette less
3) distort less
4) flare less
5) have more or less the same size & weight
Admittedly those "better" lenses were once much more expensive when new. But the tradeoffs can be much less than you seem to imply.

That said, I'm a fan of very compact and corrected slow lenses as well...

I've never ever heard of lenses expressly being designed to be less sharp, unless you're talking about portrait and/or "soft" lenses

The tradeoffs inherent to the physics of optics are usually mitigated by increasing the size of elements across the axis, added elements, better coatings, etc. A major tradeoff is mass. For many brands a 50/2 is almost 30% less weight than a 50/1.4, and usually less than half the price, with both having near equal sharpness and distortion at f/2.8.

I had a Zeiss 50 for my Pentax system. It had superb center sharpness and resolution and great colour rendering. Its edge distortions were noticeable until 2 stops down from max. It was also worth 2.5x more than a Pentax brand equivalent but in real life photos, it was hard to see the differences. It had great all around performance, but there was a flaw based on the unavoidable optical physics limitations. I could get the same performance out of much less expensive glass at the expense of 1-stop.

I therefore concluded biggest discrepancy is price vs. noticeable distortion in real life photos.

 

[Rol_Lei Nut]

The tradeoffs inherent to the physics of optics are usually mitigated by increasing the size of elements across the axis, added elements, better coatings, etc. A major tradeoff is mass. For many brands a 50/2 is almost 30% less weight than a 50/1.4, and usually less than half the price, with both having near equal sharpness and distortion at f/2.8.

I had a Zeiss 50 for my Pentax system. It had superb center sharpness and resolution and great colour rendering. Its edge distortions were noticeable until 2 stops down from max. It was also worth 2.5x more than a Pentax brand equivalent but in real life photos, it was hard to see the differences. It had great all around performance, but there was a flaw based on the unavoidable optical physics limitations. I could get the same performance out of much less expensive glass at the expense of 1-stop.

I therefore concluded biggest discrepancy is price vs. noticeable distortion in real life photos.

A conclusion based on a sample of one?!!? :confused:

I think the key word you used is "usually": while faster lenses often (usually) do have to compromise some performance aspects, the best ones manage to touch several sweet spots...

 

[Aristophanes]

A conclusion based on a sample of one?!!? :confused:

I think the key word you used is "usually": while faster lenses often (usually) do have to compromise some performance aspects, the best ones manage to touch several sweet spots...

Yes, they do. But the laws of physics demand all lenses have tradeoffs, especially wide open. It is unavoidable. Look and ye shall find.

If there weren't all manufacturers would gravitate towards an identical design.

 

[Rol_Lei Nut]

Yes, they do. But the laws of physics demand all lenses have tradeoffs, especially wide open. It is unavoidable. Look and ye shall find.

If there weren't all manufacturers would gravitate towards an identical design.

The main tradeoff for manufacturers (and consumers) is often cost. The fast lenses with good allround performamance are usually expensive.

 

[keithwms]

Ah physics

Anyway, the basic point, for those who care to know, is that lens design issues tend to reduce resolution at wide apertures, whereas diffraction tends to reduce performance at small apertures. Thus the best performance is typically at intermediate apertures. For RF lenses, the best performance is often seen a stop or two wider open than for SLRs. But that difference is rapidly disappearing now, with all the fancy aspherical corrections etc., assuming you can afford them. Which is a big "if" for those not earningsteady income from their photography.

What constitutes "best performance" is certainly open for interpretation. What you typically see is center performance at or near its very best when the lens is stopped down a small amount (a stop or two or three) while corner performance is often lacking until ~f/8. When people speak about performance overall, they tend to mean some sort of average across the frame and across all the frequencies. For that reason, the concept of best performance is really never going to sit well with everyone. We all have different needs and preferences.

My [very] broadbrush observation is that RF shooters tend to be a bit biased toward the center performance... due to the focusing mechanism. Whereas SLR users tend to be biased towards the third lines. So when people speak of high performance, it helps to keep these things in mind: how you tend to frame, and what frequency info is important... not to mention colour rendition, which is another subject entirely, since MTF charts are usually shot at one wavelength or two.

At the end of the day, as has been said many times before, you just have to experiment and go with your gut instinct. Its not worthwhile to sweat minor technical details such as only getting 70% performance wide open at the edge of a frame. Most lenses out there will do marvelous rendition, where it matters most, at all reasonable apertures.

If it were possible to quote performance per dollar, the contax G lenses would win, hands down. By a long shot.

 

[Aristophanes]

The main tradeoff for manufacturers (and consumers) is often cost. The fast lenses with good allround performamance are usually expensive.

Cost. Substantially:

http://www.bhphotovideo.com/c/product/332585-USA/Leica_11891_50mm_f_1_4_Summilux_M.html

$3,995

http://www.flickr.com/photos/28753682@N06/6005248119/

http://www.bhphotovideo.com/c/product/40755-USA/Pentax_20817_Normal_SMCP_FA_50mm_f_1_4.html

$359.95

http://www.flickr.com/photos/kaherdin/6286544413/

Worth 8x the price and 40% more weight?

OK. I am comparing marketing extremes, which is fun

 

[keithwms]

Bah.... Nikon 50/1.2, $450, and worth every penny.

 

[zsas]

^My dream lens (and I don't even own a Nikon....)

 

[EKDobbs]

Bah.... Nikon 50/1.2, $450, and worth every penny.

I will both second and third that. That was my glass investment for the year, and nothing has looked or felt better since.

 

[Aristophanes]

Bah.... Nikon 50/1.2, $450, and worth every penny.

http://www.bhphotovideo.com/c/product/36976-USA/Nikon_1435_NIKKOR_Normal_50mm_f_1_2.html

$699.95 new.

http://www.flickr.com/photos/patrickjoust/2611398895/in/photostream/

 

[keithwms]

See I praise something and its value goes up, interesting how that works!

I bought it for $420 a couple years ago.

 

[zsas]

I have seen that a lot too lately, I bought a lens for $200ish 3 years ago, it is now almost $400! I should'a bought 100 of em...

 

[clayne]

Ah, but there are other lenses which are just as good as the 50/1.2 Ai-S, I'm just not going to say what they are. ;-)

Even then, "good" is entirely relative. One can't, and probably shouldn't, shoot at 1.2 every single exposure.

 

[Thomas Bertilsson]

I like every single lens I own wide open, particularly the 50mm Summitar f/2, 55mm f/2 Pentax, and the 80mm f/2.8 Planar for the Hasselblad. No need for anything better.

 

[Rol_Lei Nut]

Cost. Substantially:

http://www.bhphotovideo.com/c/product/332585-USA/Leica_11891_50mm_f_1_4_Summilux_M.html

$3,995

http://www.flickr.com/photos/28753682@N06/6005248119/

http://www.bhphotovideo.com/c/product/40755-USA/Pentax_20817_Normal_SMCP_FA_50mm_f_1_4.html

$359.95

http://www.flickr.com/photos/kaherdin/6286544413/

Worth 8x the price and 40% more weight?

OK. I am comparing marketing extremes, which is fun

Yes, one lens is very expensive (especially new).
But I don't understand what, if anything, the images are supposed to prove: very fast lenses used practically as macros (one being a rangefinder lens!), shown as small jpg images...
At that size you could almost show "sharp" results from a pinhole lens!

 

[clayne]

Pentax SMC 50/1.4 is a perfectly fine lens both wide-open and not.






IMO, photographers who only buy lenses so they can shoot them wide-open 100% of the time are dependent on that "look" - and that look won't last if there isn't something deeper than that.

 

[Thomas Bertilsson]

Pentax SMC 50/1.4 is a perfectly fine lens both wide-open and not.






IMO, photographers who only buy lenses so they can shoot them wide-open 100% of the time are dependent on that "look" - and that look won't last if there isn't something deeper than that.

I think it's about choosing the aperture that's right for the picture. I happen to like a 25mm aperture for portraits, for example. 35mm lens at f/1.4 or 50mm lens at f/2.
Then if I'm shooting landscape I like more depth of field. So it depends.

 

[dugrant153]

So after much deliberation I decided to go and replace my failing Nikon 50mm with a Zeiss ZF2 equivalent.
I thought a rangefinder would do for me but the cost of starting a whole new system was going to be out of my budget. I was thinking Bessa's but with Canada not having a supplier it would be tough to get any much needed service.

That and I have some pretty good Nikon gear.
After some thinking, I think by wide open, I'm looking for a lens that can go to F2 or F1.4 and provide a very distinct 3d effect. So resolution is not going to be a big deal for me as long as the images don't come out too soft or lacking a ton contrast.

I have my eye on either the Zeiss Makro Planar 50mm f2 or the Zeiss Planar 50mm f1.4. Hmmm...

 

[brucemuir]

I have my eye on either the Zeiss Makro Planar 50mm f2 or the Zeiss Planar 50mm f1.4. Hmmm...

There is endless debate on the virtues of both these over on fredmiranda. You may want to peruse the info there.

I think I'd go with the makro planar f/2 but I already have the C/Y planar in 1.4 and several 1.4 Nikkors also.

 

[clayne]

It's about the light and the subject. No lens will make up for that. There is no magic bullet.

 

[Thomas Bertilsson]

It's about the light and the subject. No lens will make up for that. There is no magic bullet.

I agree with this. Often I get very tired of the 'bokeh' debate, and just want to shake folks so they could stop obsessing over it so much. Just show the damned picture. And, I may have submitted myself to the lion's den...