Which is Sharper

[NewSuw]

Hi, new nikon user here which is sharper if this lense fight head on....

Tamron 28-75mm f/2.8 -VS- Sigma 24-78 f/2.8

Sigma 17-50mm f/2.8 -VS- Tamron 17-50mm f/2.8 -VS- Tokina 16-50mm f/2.8

if possible can put picture from the lense ^^
tq

[zcf]

Take some time to read the review on this website then compare
http://photozone.de/reviews

[spartacus.ret]

tamron on both counts.

[bigbird17]

of cos tamron. i tried both, both are equally sharp only depending which range u prefer

[NewSuw]

Thx guys for the response ^^
and thx for the review link
love it so much

[teebs]

Pic taken with my Tamron 17-50f2.8. No editing done at all. Just resized.

Focal Length: 26mm
Aperture: F2.8
Speed: 1/50s
ISO: 1,600



And this is the 100% cropped image from the original pic.

[pethuel]

hmm do you consider that sharp?? i feel that its quite... ok only...

anyone has some other crops of the other lenses?

[teebs]

Originally Posted by pethuel hmm do you consider that sharp?? i feel that its quite... ok only... anyone has some other crops of the other lenses?

Just for your info, sharpness of an image depends on the aperture that you take at. The larger the aperture, the thinner the DOF and the less sharp the image becomes because the area of the image that is in focus becomes much smaller. Furthermore most lenses are at their sharpest when stopped down 2 stops or more from their largest aperture.

Series of 4 pics taken at different apertures. Focus is at the rim of the centre of the pot. All are 100% crops from actual sized pics.

[calebk]

Originally Posted by teebs Just for your info, sharpness of an image depends on the aperture that you take at. The larger the aperture, the thinner the DOF and the less sharp the image becomes because the area of the image that is in focus becomes much smaller. Furthermore most lenses are at their sharpest when stopped down 2 stops or more from their largest aperture. ...

Misconcepted.

Sharpness is the resolving power of a lens.

Aperture affects the depth of field, which is the area in focus from the image plane.

Stopping down gives you more depth of field, which increases the level of perceived sharpness in an image.

[teebs]

Originally Posted by calebk Misconcepted. Sharpness is the resolving power of a lens. Aperture affects the depth of field, which is the area in focus from the image plane. Stopping down gives you more depth of field, which increases the level of perceived sharpness in an image.

Yes, sharpness is the resolving power of the lens but to get that information we need to use test charts and software to analyse the test charts taken with the lens.

But in practical circumstances, when people are looking for sharp copies of lenses, they are actually looking for lenses that have perfect focus.

But even for lenses with perfect focus, the pics they take will only be "sharp" if the aperture is stopped down sufficiently so that the depth of field is wide enough to render the image "sharp".

Correct me if what I said is wrong...

[calebk]

Originally Posted by teebs Yes, sharpness is the resolving power of the lens but to get that information we need to use test charts and software to analyse the test charts taken with the lens. But in practical circumstances, when people are looking for sharp copies of lenses, they are actually looking for lenses that have perfect focus. But even for lenses with perfect focus, the pics they take will only be "sharp" if the aperture is stopped down sufficiently so that the depth of field is wide enough to render the image "sharp". Correct me if what I said is wrong...

Yup that's mostly right. However, as what I've said earlier, this stopping down results in a perceived sharpness.

[Gunjack]

Hmm... the pics at F2.8 and F4 does not seem very sharp. Is it due to front focuss errors? I had the tamron 28-75mm F2.8 and it was not sharp untill i got it calibrated, then it was sharp even at F2.8 aperture!

Originally Posted by teebs Just for your info, sharpness of an image depends on the aperture that you take at. The larger the aperture, the thinner the DOF and the less sharp the image becomes because the area of the image that is in focus becomes much smaller. Furthermore most lenses are at their sharpest when stopped down 2 stops or more from their largest aperture. Series of 4 pics taken at different apertures. Focus is at the rim of the centre of the pot. All are 100% crops from actual sized pics.

[night86mare]

Originally Posted by teebs But in practical circumstances, when people are looking for sharp copies of lenses, they are actually looking for lenses that have perfect focus. But even for lenses with perfect focus, the pics they take will only be "sharp" if the aperture is stopped down sufficiently so that the depth of field is wide enough to render the image "sharp". Correct me if what I said is wrong...

the first paragraph is true, since most of the sharpness problems has more to do with the calibration rather than something wrong with the elements/interiors.

the second is not really that true, lenses tend to resolve better around a certain region, it has to do with pushing the performance of the lens. for example, usually most lenses do not attain maximum sharpness, or resolution of detail.. wide open. they do it better at a sweet spot, which starts 2 stops or so down from the wide open aperture. for most lenses, f/8 to f/11 are the sharpest apertures to use.

but we're being overly pedantic, aren't we?

as well as comparing an apple to an orange, i have no idea why people want to compare sharpness of 28-75 to 17-50.. you won't compare a 50mm prime lens to a 400mm prime lens, would you? they are different ranges, and you simply cannot apply them to the same purpose. unless if you say ff versus crop factor.

[Gunjack]

Here is a sample pic shot on the Tamron 90mm Macro at F2.8 Max Aperture



Here is the 100% crop of the area in focus at F2.8 Max Aperture. No modification except to resize. Looks sharp enough for me!



I believe most of the sharpness issues are due to focussing errors, rather than the lens optics performance. Any of the lens should be quite sharp if it can focus accurately. For third party lens, make sure you get one with no front or back focussing issues. Those cameras which can calibrate their AF for the different lens should have no issues though.

[teebs]

Originally Posted by night86mare the first paragraph is true, since most of the sharpness problems has more to do with the calibration rather than something wrong with the elements/interiors. the second is not really that true, lenses tend to resolve better around a certain region, it has to do with pushing the performance of the lens. for example, usually most lenses do not attain maximum sharpness, or resolution of detail.. wide open. they do it better at a sweet spot, which starts 2 stops or so down from the wide open aperture. for most lenses, f/8 to f/11 are the sharpest apertures to use. but we're being overly pedantic, aren't we? as well as comparing an apple to an orange, i have no idea why people want to compare sharpness of 28-75 to 17-50.. you won't compare a 50mm prime lens to a 400mm prime lens, would you? they are different ranges, and you simply cannot apply them to the same purpose. unless if you say ff versus crop factor.

Well, I guess it's human nature to compare...even between apples & oranges, durians and mangoes...

But I don't remember people comparing lenses for focus or sharpness back in the old film days. Maybe it was because most photos were printed in 4R, 6R, 8R, S8R etc and at these sizes, people weren't really going to be able to pixel peep...

[calebk]

Originally Posted by teebs Well, I guess it's human nature to compare...even between apples & oranges, durians and mangoes... But I don't remember people comparing lenses for focus or sharpness back in the old film days. Maybe it was because most photos were printed in 4R, 6R, 8R, S8R etc and at these sizes, people weren't really going to be able to pixel peep...

Ah the luxury and the distress that pixel peeping brings about.

[bigbird17]

i got the 2875. super sharp even wide open