[houstonmacgregor]

Been trying to decide between the sigma and tamron lenses and the comment is always made that the tamron is sharper. Howevr between the adjustment that can be made on the k-7 ( not sure about the K20) and PP, what difference does it make which lens itself is sharper.

[CWyatt]

No software can re-create the effect of a 'sharp' lens, it can only increase contrast between pixels, making an image appear sharper, to a point.

'Sharp' lenses will render things more naturally, capture more detail, and often with better contrast and colour. They can give you much more leeway in PP.

[KxBlaze]

I have yet to see a shaprening tool that can make a picture look sharper naturally. Most sharpening tools can sharpen an image very slightly but nothing compared to going from an ok lens to a sharpe lens.

In my opinion PP is great for color vibrance/saturation, contrast, brightness, clarity....actually most everything except for sharpening.

[Internetpilot]

Keep in mind that a statement like, "Tamron lenses are always sharper", even if you hear that from multiple people, is still rather subjective. There are plenty of sharp lenses out there with a Sigma logo on them, just like I'm quite certain I can find some people who complain that their particular Tamron lens of choice is soft.

That being said, it does matter if you can get a sharp lens right out of the box. Also keep in mind that most lenses are not as sharp wide open, but some get sharper than others when you stop them down. Unfortunately, this can also be true between lenses of the same namebrand and model number, but there's usually not so much of a variance in mid to upper level lenses.

Sorry -- just adding my two cents.

-- Chris

[RioRico]

The above comments pretty much cover it. Sharpness and detail can be subtracted in PP, not added. Softness and blur can be added, not subtracted. Start with a sharper lens. Most (but not all) lenses are quite sharp when stopped-down. But it's best to start with a sharp lens.

That said, at times you'll want a softer image, maybe in ways that can't be done in PP. That's the time to use a softer lens. Fast lenses are typically soft when wide-open. A lens whose objective has a network of fine scratches can give a "glowing halo" effect. These effects have their place. But start with a sharp lens.

[yeatzee]

What lenses are you comparing?

[rawr]

Agree with all the above. There is no substitute for sharpness - ie usable resolution, or the amount of detail the lens can pull in. You can correct optical distortion, purple fringing, poor contrast etc in post-processing but you can't put information back into an image that wasn't captured in the first place by the lens.

Having said that, if you have the world's sharpest lens, but a poor camera technique that see's you blurring every shot due to camera shake or missed focus, or losing detail by poorly exposing all the time, you won't gain much from the sharpness of the lens. It's all a balancing act.

[tibbitts]

Been trying to decide between the sigma and tamron lenses and the comment is always made that the tamron is sharper. Howevr between the adjustment that can be made on the k-7 ( not sure about the K20) and PP, what difference does it make which lens itself is sharper.

I assume you are comparing the 70-300mm lenses, but you might specify if you're comparing the Sigma APO, or the regular Sigma.

In any case, I don't think you can really create sharpness with software, you can just produce an appearance of greater sharpness than actually exists.

Paul

[houstonmacgregor]

sigma 70-200 vs tamron 70-200

sigma 18-50-tamron 17-50 and pentax 16-50

These have been discussed numerous times

[Prox-iee]

I heard the sigma 50mm prime is legendary sharp. Better the Nikons and Canons 50mm. Idk how well it fairs against the pentax 50mm though. Pentax is know for their primes

[Marc Sabatella]

It is true that sharpening in PP cannot make a less sharp lens outperform a more sharp lens.

It is also true that in practice, the difference in sharpness between two otherwise similar lenses is usually not big enough to worry about.

[Wheatfield]

Consider also, is the lens sharp enough?
Or, is it perhaps too sharp?
Sometimes, the sharpest lens is as much of a detriment as a soft lens in other situations.

[MRRiley]

This is fundamentally a lens question so thread was moved to the Lens forum