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02-14-2011, 10:51 PM   #16
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Well said, noblepa. Sometimes we want total sharpness, and sometimes we don't, and either can be achieved with lenses selection and careful use of focus and DOF. Using a lens at its soft spot is rather like using a cheap tele or a flawed lens with notable character -- the content is more important than the resolution and details. I don't use my FA50/1.4 or Tomioka 55/1.4 or Tak-B 135/2.5 or various other glass wide open when I want maximum detail -- I use them when I want the subject to leap from the frame.

And that is why I use all sorts of non-camera lenses (enlarger, projector, meniscus, etc) on bellows, because I can obtain effects that aren't obtainable otherwise. Something I just found today: Take a Raynox DCR-250, which is a +8 dioptre. Put a +2 dioptre 49mm screw-in on its front threads. Put a 42-43mm step ring on its base; mount that on an M42 bellows; mount that on a dSLR. Hey, now it's a soft 100/2.5 lens! The centre is somewhat sharp, all else is soft and lucent, a nice setup for dreamy romantic portraits. And I don't even have to pull up a Pastel filter in PP!

Lenses in the f/1.4 neighborhood, no matter the focal length, are sophisticated tools. A bit of training and practice are needed to master them. Oh Goddess, not another learning experience!

02-15-2011, 12:42 AM   #17
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lol @ the not another learning experience! I totally feel that. There's just sooo much to learn about photography which is both for me, a blessing and a curse.

I'm glad I asked this question though as it has brought a wealth of information and opinions which has been great for me. Thank you.
02-15-2011, 03:56 AM   #18
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Nic, the FA 50/1.4, like all other fast fifties are decent lenses but don't have the best numbers in wide open tests done on them. But we don't shoot with these lenses in labs, we shoot them in real world situations, and for these they don't do too badly wide open.

DoF is one thing, but the lenses are certainly useable wide open - results such as these with the FA 50/1.4 (pertinent to your intended use of the lens) at or very near wide open may help to show that the sharpness is quite acceptable:



02-15-2011, 01:47 PM   #19
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What beautiful wide eyed children! Thanks for showing me those Ash, it does show me how good they are wide open. Can't wait to actually pik mine up on Satruday, I'll be off to do some shooting with it

02-15-2011, 03:04 PM   #20
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QuoteOriginally posted by NicoleAu Quote
lol @ the not another learning experience! I totally feel that. There's just sooo much to learn about photography which is both for me, a blessing and a curse.

I'm glad I asked this question though as it has brought a wealth of information and opinions which has been great for me. Thank you.
There was a period of time when I was like a teenager: I figured I already knew all there was to know about photography. The Internet and digital SLRs sure changed that in a hurry.
02-16-2011, 12:11 PM   #21
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Some more evidence that wide open is still usable.

Sorry for the frog but I think its a good example.
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02-16-2011, 05:34 PM   #22
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I like frogs, so don't be sorry. The sharpness isn't too bad at all.
02-17-2011, 05:10 AM   #23
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The diameter of a lens' opening plays a big role in the sharpness of its image. Here's a schematic diagram from Carl Zeiss showing a natural lens defect called "spherical aberration":


The light rays going through the edges of the lens don't focus at the same point as those coming through the middle. Clearly the image will be sharper if an aperture is used to cut off those edge rays.

If the shape of the lens is ground differently, then those edge rays can be brought to focus at the same place as the center rays - but this is expensive to do, and can't be done perfectly. Each correction made causes another problem - much like life in general.

That's basically why fast lenses cost more and are softer when wide open.

Dave

02-17-2011, 09:17 AM   #24
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Most of the answers fail to remember that these "faster" lenses were generally introduced at the time when film speeds (ISO settings) were generally much lower. We are now used to being able to dial in high ISO settings on our digital cameras if necessary and it is quite common to standardise in general shooting at 200 or even 400 ISO or more. When I started colour photography, Kodak had just brought out a new version of Kodachrome with a massive speed of 10 ISO (up from 8 ISO) and it was to be another nearly 10 years before this was increased to 25 ISO. There were films such as Agfa CT18 with a speed of 50 ISO and Ektachrome had a film at 32 and then 64 ISO before they brought out "High Speed Ektachrome" at 160 ISO in about 1966. Even prior to switching to digital 7 years ago, my normal film was either 100 ISO or 200 ISO and of course once the film was in the camera you couldn't change it! To get back to the "faster" lenses, these were purchased mainly to enable higher shutter speeds to be used, and they generally gave acceptable results when used wide open, hence their high cost! My early shots with 10 ISO on a Kodak Retinette on a bright summer's day were normally at best around f5.6 at 1/30 second - it was hopeless if it was dull!

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02-19-2011, 12:24 PM   #25
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Here are a few wide open shots with the SMC-M 50mm F1.4, I'd say they are usable. Not sharp as a tack, but definitely usable...





02-19-2011, 01:04 PM   #26
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It is a very sharp lens. I think you will really enjoy it. I rarely take it off my k10d. I have found 2.5 to be my sweet spot on the 50 1.4. At 1.4 the boken is a bit choppy and really hard to nail with a moving subject.
Well done Ash and beautiful subjects.
02-19-2011, 09:09 PM   #27
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I have it and have been playing with it. I had it at 1.8 and I'm guessing the subject was too far away as the soft it really really soft But from about 2.2 and up it's looking great
02-19-2011, 10:21 PM   #28
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Nic, the best results with this lens wide open (or near wide open, to about f/2) are with subjects that are not too close and not too far away from the subject. Stratmen's examples are good to illustrate this as in #1, the subject is mid-range and decently sharp, whereas in #2 and #3 the subject is pretty close and makes depth of field *really* thin, which some can mistake as softness.

In my examples, the subjects are about 1-1.5m from the lens which has a desired thin DoF without being soft in the important parts of the portrait. Of course, it also helps to ensure the plane of the subject (face) is as near to perpendicular to the lens as possible for the sharpness to be appreciable throughout the subject matter.
02-20-2011, 10:38 AM   #29
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Think of it this way: We don't use a superfast 50 wide open if we want supreme sharpness; we use it to get otherwise-impossible shots. For edge-to-edge flatfield sharpness, use an enlarger or macro lens stopped down to f/8. To get a dramatic candle-lit scene, use a wide-open 55/1.4 or something of that sort. For excellent sharpness, stop that one down to f/8. Many sins are washed away at f/8, eh?
02-20-2011, 11:39 AM   #30
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A lot of good replies. While the DOF is small wide open on these lenses, it is very useful at times. It's really a question of "Why are you buying it if you aren't going to use it"? Actually, there aren't a lot of choices today for a 50. Way back in the day, there were 50-55 mm lenses sold that were f/1.2, f/1.4, f/1.7, f/1.8, and f/2. Most of us bought cameras with the f/1.7,f/1.8, or f/2 as a kit, depending on when you bought it. You paid extra $$$ for the faster ones. Today it seems the f/1.4 is the only model made other than the f/2.8 macro. You do get the benefit of a very bright f/1.4 viewfinder even if you aren't shooting wide open.
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