That's usually the case, but the quality of the lens is a major factor too. The prime 50mms are notoriously poor at f/1.8, but that's also reflected in the price.
I've just purchased a Fuji X100 and that lens is great at f/2, it's widest setting, but better still at f/8. But the disparity is not as big as your example. I'm surprised!
Thanks, I was wondering about this. I would also like to do a test of these setting done on subjects positioned further away. 50mms are good for portraiture, but what I don't know is how much you should ideally get all up in person's face..and how that distance affects the ideal apeature or if it does. Time for a book I guess.
Anyway, thanks for sharing. That guy's style of writing is funny. Wait, that's you....Your writing is funny!
i did read an article by Elizabeth Halford about the sharpness of a lens:
"This may hit some beginners like a ton of bricks so brace yourself for a mild disappointment here: your lens isn’t wonderful at all f/stops. Yup. A Canon nifty fifty which opens to f/1.8 isn’t at its best when it’s wide open. And by ‘best’, I mean when a lens it at its sharpest. You see, there’s something known as a lens’ ‘sweet spot’ which is the aperture at which it’s at the sharpest and sometimes will even offer other things like better clarity. It’s hard to give a blanket statement about the exact sweet spot for each lens because when you look up the chatter on the internet, there are such varying statements about, say, the sweet spot for the aforementioned Canon 50mm f/1.8. Some say it’s f/2.2 while others claim that the sweet spot is f/4. A good rule of thumb is that a lens starts moving more towards perfection about two stops above its maximum aperture. So where an f/1.8 can open all the way to f/1.8, you don’t actually want to shoot at f/1.8 if you want optimal sharpness and clarity. Try moving up a couple stops to f/2.2 or f/2.8 and compare the results you achieve.
While you can get info on the internet about your favorite lens’ sweet spot, the best thing you can do is set up a scenario and take a shot at all different apertures. You can do this by setting your camera on AV (or A on a Nikon) which is aperture priority mode. This means you will be able to change only the aperture and the camera will take care of all the other settings for you while you carry out your test. I would recommend using a tripod to eliminate factors that can alter sharpness like camera shake. After taking the photos, look at the images at 100% in your computer and you’ll notice some are sharper than others. Note the apertures used for those shots and you’ll know where to stay when shooting with that lens from then on.
I can hear you thinking: so I just spent over $1k on an f/1.2 and I can’t actually use my lens at f/1.2? I feel your pain – I’ve already gone through that grieving process myself! When talking about 50mm lenses, you could say that…the max aperture
• on a f/1.8 is f/2.2
• while the max aperture on an f/1.4 is f/1.8
• and on a f/1.2, it’s going to be f/1.6
So you see, you’re still getting wider apertures, just not as wide as you may have first thought. But don’t let this sweet-spot-business discourage you from experimenting with and employing all sorts ofwonderful wide-open apertures. It’s just important to understand how your gear works and how to get the best out of it."
these are the kinds of discussions i fully lap up on this site. i've a huge learning curve in regards to all things photography... thanks for bringing this topic up, Doctor What
Expensive glass is usually just fine wide open. Usually. @ronphotography summed it up well. That said, my 85mm f/1.2 is near perfect at f/1.2, and only a breath better at f/1.6. In fact, it is sharper at f/1.2 than my (amazingly sharp) 24-70 f/2.8 is at f/4.0-f/5.6. But then, it's a $3.5k lens, so that is to be expected.
Lenses may not be optimal wide open, but expensive lenses are usually very solid performers, and give exceptional results regardless of the aperture used.
What is perhaps more interesting, is that using apertures smaller than f/8 on a crop-frame camera (f/11 on full-frame 35mm) begins to soften your images and actually negates the increased DOF benefits. Approximate f-stops of course - it is slightly different for each camera. F/22 for better DOF in your landscape? Don't bother. ;)
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I've just purchased a Fuji X100 and that lens is great at f/2, it's widest setting, but better still at f/8. But the disparity is not as big as your example. I'm surprised!
Anyway, thanks for sharing. That guy's style of writing is funny. Wait, that's you....Your writing is funny!
"This may hit some beginners like a ton of bricks so brace yourself for a mild disappointment here: your lens isn’t wonderful at all f/stops. Yup. A Canon nifty fifty which opens to f/1.8 isn’t at its best when it’s wide open. And by ‘best’, I mean when a lens it at its sharpest. You see, there’s something known as a lens’ ‘sweet spot’ which is the aperture at which it’s at the sharpest and sometimes will even offer other things like better clarity. It’s hard to give a blanket statement about the exact sweet spot for each lens because when you look up the chatter on the internet, there are such varying statements about, say, the sweet spot for the aforementioned Canon 50mm f/1.8. Some say it’s f/2.2 while others claim that the sweet spot is f/4. A good rule of thumb is that a lens starts moving more towards perfection about two stops above its maximum aperture. So where an f/1.8 can open all the way to f/1.8, you don’t actually want to shoot at f/1.8 if you want optimal sharpness and clarity. Try moving up a couple stops to f/2.2 or f/2.8 and compare the results you achieve.
While you can get info on the internet about your favorite lens’ sweet spot, the best thing you can do is set up a scenario and take a shot at all different apertures. You can do this by setting your camera on AV (or A on a Nikon) which is aperture priority mode. This means you will be able to change only the aperture and the camera will take care of all the other settings for you while you carry out your test. I would recommend using a tripod to eliminate factors that can alter sharpness like camera shake. After taking the photos, look at the images at 100% in your computer and you’ll notice some are sharper than others. Note the apertures used for those shots and you’ll know where to stay when shooting with that lens from then on.
I can hear you thinking: so I just spent over $1k on an f/1.2 and I can’t actually use my lens at f/1.2? I feel your pain – I’ve already gone through that grieving process myself! When talking about 50mm lenses, you could say that…the max aperture
• on a f/1.8 is f/2.2
• while the max aperture on an f/1.4 is f/1.8
• and on a f/1.2, it’s going to be f/1.6
So you see, you’re still getting wider apertures, just not as wide as you may have first thought. But don’t let this sweet-spot-business discourage you from experimenting with and employing all sorts ofwonderful wide-open apertures. It’s just important to understand how your gear works and how to get the best out of it."
Lenses may not be optimal wide open, but expensive lenses are usually very solid performers, and give exceptional results regardless of the aperture used.
What is perhaps more interesting, is that using apertures smaller than f/8 on a crop-frame camera (f/11 on full-frame 35mm) begins to soften your images and actually negates the increased DOF benefits. Approximate f-stops of course - it is slightly different for each camera. F/22 for better DOF in your landscape? Don't bother. ;)