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Canon FD 24mm f1.4 L
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PostPosted: Sun Mar 18, 2012 12:01 pm    Post subject: Canon FD 24mm f1.4 L Reply with quote
All shot with f1.4, adjust WB, no other PP, but standard sharpening during jpg output.

#1


#2


#3


#4


PostPosted: Sun Mar 18, 2012 12:57 pm    Post subject: Reply with quote
great portraits, nice on the Nex


PostPosted: Sun Mar 18, 2012 1:37 pm    Post subject: Reply with quote
poilu wrote:
great portraits, nice on the Nex


+1


PostPosted: Sun Mar 18, 2012 3:06 pm    Post subject: Reply with quote
That lens is still sold for high prices. Congratulations!


PostPosted: Sun Mar 18, 2012 4:07 pm    Post subject: Reply with quote
wow this is quite the lens! amazing f1.4 at that focal length


PostPosted: Sun Mar 18, 2012 10:04 pm    Post subject: Reply with quote
iangreenhalgh1 wrote:
poilu wrote:
great portraits, nice on the Nex

+1

Smoli4 wrote:
wow this is quite the lens! amazing f1.4 at that focal length


Thanks. I have seen the EF 24/1.4 on 5Dm2 and canon crop. Personally, I like the color from nex better. This lens excels in low light and narrow spaces. I am surprised myself how it performs at f1.4.

LucisPictor wrote:
That lens is still sold for high prices. Congratulations!

Thanks Carsten. I was very lucky and got this lens from one of the best photographer and writer: http://ingeovetysnes.com/ .


PostPosted: Mon Mar 19, 2012 7:28 pm    Post subject: Reply with quote
Amazing sharpness...and the perfect concentic airy rings in the bokeh on #4, even on the edges, really shows the optical excellence of this lens.
Now I want one even more Smile


PostPosted: Thu May 17, 2012 9:43 am    Post subject: Reply with quote
Have you shot any scenery with it, Hoan? How is the corner performance on the NEX?

Incidentally for lovers of wide-angle on the NEX, I tried a Contax G 21/2.8 on NEX-5n yesterday and it is different to the Zeiss 21/2.8 ZM! This I did not expect. The Contax is sharp from corner to corner close up and at infinity focus but does show colour cast on the borders (whereas the Zeiss was very soft in the borders at infinity focus but didn't show any colour cast that I could see). The Contax didn't have much colour cast actually. If people are happy with Cornerfix, or shoot a lot of B&W or indoor, there's not much of it it seems. More the skies and scenes with a lot of light seem to be the problem.

Nice lens and with Metabones adapter not bad to handle. Might be a keeper especially if one hopes for a more wide-angle friendly NEX-9 one day...


PostPosted: Thu May 17, 2012 1:59 pm    Post subject: Reply with quote
Daniel,
I will make a new set to test it out.


PostPosted: Thu May 17, 2012 2:05 pm    Post subject: Reply with quote
That'll be great! Thanks, Hoan, - I've been eying this lens. Seems like a great piece of glass that can be had for under $1000, but as we have been discovering, not all great glass produces great results on the NEX.

If I recall correctly I saw a test of the EF version on an early Canon dSLR that was not great in the borders. While Rockwell says it is fantastic. Could be similar issues with microlenses, I am not sure.

PS Good pics of your boy (right?). I like the second for expression and the third for the scene and he bokeh. The light looks to be a bit harsh, seems like the lens did a good job with it.


PostPosted: Mon May 21, 2012 8:33 am    Post subject: Reply with quote
sammo wrote:
...and the perfect concentic airy rings in the bokeh on #4, even on the edges, really shows the optical excellence of this lens.
Now I want one even more Smile


I think that are not airy rings, but the onion ring bokeh of an aspherical lens. Ary disks should be visible only very small somewhere at diffraction limit.
These onion rings are the reason why I don´t like my converted FD 24/1.4L that much.


PostPosted: Tue May 22, 2012 6:37 am    Post subject: Reply with quote
ZoneV wrote:

I think that are not airy rings, but the onion ring bokeh of an aspherical lens. Ary disks should be visible only very small somewhere at diffraction limit.
These onion rings are the reason why I don´t like my converted FD 24/1.4L that much.


Is there some thing I can do to avoid the onion ring effects? Like distances, apertures?
Can you redirect me to an url explain the ring causes? Thanks.

This lens, and especially the canon fd 85/1.2, has onion rings that is hard to avoid.
I though they were caused by the light sources, but after more testing, they are independent, and more caused by optic design.


PostPosted: Tue May 22, 2012 7:22 am    Post subject: Reply with quote
These "onion rings" are Airy disks. They show if lens has spherical abberation or not reganding if they are stronger in back- or front-out of focus objects. This lens is probably slightly overcorrected as suposed to be typical for aspheric lenses, therefore the backfocused point lights show Airy disks, and it's extremely well corrected for other abberations so Airy disks are also easier to see.


PostPosted: Tue May 22, 2012 8:47 am    Post subject: Reply with quote
Thanks,
I read through wikipedia, and found: http://en.wikipedia.org/wiki/Airy_disk
Don't ask me about the maths.

"...In a camera or imaging system an object far away gets imaged onto the film or detector plane by the objective lens, and the far field diffraction pattern is observed at the detector. The resulting image is a convolution of the ideal image with the Airy diffraction pattern due to diffraction from the iris aperture or due to the finite size of the lens. This leads to the finite resolution of a lens system described above."

seems unavoidable.
What about a plugin in LR or photoshop to blur/remove the airy disks?


PostPosted: Wed May 23, 2012 1:27 pm    Post subject: Reply with quote
Friends

Last edited by hoanpham on Sat Jan 02, 2016 12:12 pm; edited 1 time in total


PostPosted: Thu May 24, 2012 8:26 pm    Post subject: Concert with canon fd 24/1.4 Reply with quote
Friends

Last edited by hoanpham on Sat Jan 02, 2016 12:12 pm; edited 1 time in total


PostPosted: Fri May 25, 2012 1:45 pm    Post subject: Reply with quote
These onion rings are no airy disks.
The onion rings show the manufacturing of the aspherical lens surface.

Airy disks size have maximum brightness in the center - these onion rings at this pictures have a minimum there.
Wikipedia http://en.wikipedia.org/wiki/Airy_disk:
"In optics, the Airy disk (or Airy disc) and Airy pattern are descriptions of the best focused spot of light that a perfect lens with a circular aperture can make, limited by the diffraction of light."
In case these onion rings are the best focused spot, the resolution of this lens would be only ~50 Linepairs per image height.
Airy disks diameter for the first minimum should be maximum ~ pixel size of the camera.
Airy disks are - a bit simplified - the point spread function of our lenses. And the complete image our camera sees, is made of a lot of small airy disks (simplified). So the airy disks better be small - and they are small, smallest with fast lenses wideopen. Here roughly 1.4 µm on the sensor.


PostPosted: Fri May 25, 2012 2:00 pm    Post subject: Reply with quote
Thanks alot for the explaination.
I need to dig deeper into this.
Is there any easy book i can borrow from the library to read more about it? Or any text book that not required advance math?

Will modern optical processes remove these marks?


PostPosted: Sat May 26, 2012 12:13 pm    Post subject: Reply with quote
It looks a little soft to me? Or do I need glasses?


PostPosted: Tue May 29, 2012 10:17 am    Post subject: Reply with quote
ZoneV wrote:
These onion rings are no airy disks.
The onion rings show the manufacturing of the aspherical lens surface.


Ok I admit I was off with the Airy disk nomenclature, but sure is closer to real effect than "onion rings". Let's call it "out of focus diffraction pattern" to be more precise. The diffraction though is the same one as one that produces an airy disk.

The information about the pattern that I wrote is true, it shows how well corrected an optical system is. I know this from telescope mirrors, which are a more precisely corrected than camera lenses, all of them are paraboloids (aspherics). Some information about recognising abberations is here: http://www.telescope-optics.net/diffraction_pattern_and_aberrations.htm


PostPosted: Thu May 31, 2012 8:38 pm    Post subject: Reply with quote
I think at telescopes one see the airy disks because of further enlarging the image from the mirror.

"Onion"rings is only a common name, not a real description about how the lens looks like.
I think only on lenses with aspherical elements sometimes (not with every light) onion rings can be seen, for example Samyang 35/1.4, Samyang 85/1.4, Canon FD 85/1.2 FD 24/1.4.
On very well regarded pure spherical lenses one see no onion rings, for example Zeiss 85/1.4 (C/Y), Zeiss 50/1.4, Zeiss S-Planar 60/4, Minolta Rokkor 58/1.2..
I am very sure that the aspherical lens surface is the reason for the "onion" rings. Airy rings from lenses with normal iris are always bright in the center.

hoanpham, Wikipedia is pretty good.
I know no source that has deeper information about bokeh, aspherical lens influence on bokeh and such.


PostPosted: Sun Apr 17, 2022 9:53 pm    Post subject: Reply with quote
Well, recently the prices for this one have gone through the roof as well:



Sadly I didn'd buy one five or ten years ago (too much focus on Minolta gear back then), but I had the opportunity to play a bit with this one. I even may be able to use this sample for some tests in the near future again Wink!

S


PostPosted: Mon Apr 18, 2022 12:18 am    Post subject: Reply with quote
Yeah the aspherical and some other fast canon glass seems to have become a thing with budding videographers.


PostPosted: Mon Apr 18, 2022 9:21 am    Post subject: Reply with quote
sammo wrote:
ZoneV wrote:
These onion rings are no airy disks.
The onion rings show the manufacturing of the aspherical lens surface.


Ok I admit I was off with the Airy disk nomenclature, but sure is closer to real effect than "onion rings". Let's call it "out of focus diffraction pattern" to be more precise. The diffraction though is the same one as one that produces an airy disk.

The information about the pattern that I wrote is true, it shows how well corrected an optical system is. I know this from telescope mirrors, which are a more precisely corrected than camera lenses, all of them are paraboloids (aspherics). Some information about recognising abberations is here: http://www.telescope-optics.net/diffraction_pattern_and_aberrations.htm


Yes, ZoneV is correct, these onion rings aren't airy disks. They are resulting from the tiny ridges left in an aspheric moulded/molded(US) glass or polymer lens. These days a lot of aspheric lenses are produced by a moulding process (sometimes glass, but often polymers, or an aspheric moulded polymer on a spherical glass substrate). These moulds are precision-milled using a diamond tool that has a finite step-resolution and leaves tiny ridges in the mould, which will therefore transfer to the optical material in the moulding process. These ridges will result in a pattern that can be seen in the out-of-focus highlights as "onion rings". Panasonic once developed a method to limit this effect, but not sure if they actually put this methodology into production:

https://www.imaging-resource.com/news/2014/05/02/the-end-of-onion-ring-bokeh-panasonic-beats-the-curse-of-aspheric-lenses

Ignore the comment in the article about Nikon being the first to bring aspheric elements to practice in 1968; Zeiss already patented a moulding process (well, sagging process really) in 1908 and was producing ophthalmoscopes with aspherical lenses as well as aspherical condensers as early as 1918 certainly.

Aspheric grinding and polishing machines for aspheric lenses do exist, and they can produce better results, but that is a far more costly production process.
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