[HoBykoYan]

Dear All,

I am currently looking for the sharpest lens that can be mounted on a Pentax DSLR. There's no restrictions on what kind of lens as long as it is a DSLR pentax mount.

Prime or zoom, manual or auto focus, old or new, third party or genuine will do.

Admin if you could help me on the voting/counting.... would highly appreciate it.

Here's what i think for now since i don't have any sharp enough lens (for now).
(Currently own F 35-105mm, DA-L 18-55mm kit, M 50 f2)

1) Sigma 70 f2.8
2) Tamron 90mm f2.8
3) M 75-150 f4

If you can attached also sample pics from your lenses, would be great.

[twitch]

Head over to photozone.de and look at the MTF charts for the lenses. You can then decide if you want centre sharpness or corner to corner, or which apertures you care about most.

My 2c is that all the limited primes, the DFA 100 macro, all DA* zooms or DA* primes are “sharp enough” for 99% of people. The Sigma 70 and Tamron 90 are often mentioned as well as incredibly sharp lenses.

A better approach I think is if you care about ultimate sharpness, just avoid the variable aperture consumer zooms.

[kytra]

Peak sharpness award goes to FA 43mm Ltd http://farm4.static.flickr.com/3554/3360548249_ca7c5d128e_b.jpg - this picture actually sold me the FA 43
Even sharpness accross the frame and aperture award goes to DA* 70mm
All Macro lenses are very sharp

You just want to pick your choice about FL, macro capability yes or no and, of course, about money.

For me the best compromise would be the 35mm f2.8 Macro if you want to go wide-ish and the DFA 100mm or the DA 70mm for portraits/mid tele.

For tele sharpness, the DA* 200mm f2.8 seems to be the best but the DA 50-135 seems an excellent choice also (with the added flexibility of a zoom but shorter max FL)

From the non Pentax mount group I can swear on the Tamron 90mm and, from reviews, the Sigma primes, especially the 105mm Macro and the 50mm HSM (I actually had the 50mm but dold it due to the fact it was so large)

From the manual focus group there are a lot of choices but as a rule, everything with true macro (1:1) should be a very sharp lens. There are some legends of course, take your time and study the lens database here.

[summonbaka]

The DA40mm for starters. Any DA and/or FA limited primes will make you more than happy. The DA seem to be slightly sharper but the FA limiteds have a distinct rendering in them.

If you want macro, Tamron 90mm or Pentax 100mm are great.

It can help if you define what are you looking for. An "ultimate lens" is without meaning if you don't like the focal length(s) of it. Is it all-around? Portraits? Walk around? Macro? Normal?

[rawr]

I'll also put in a plug for the M 50mm 1.7, as well as the DA 40. Both very sharp once stopped down a tad, and nicely sharp across the image frame from edge to edge.

Note that 'sharpest' for even the best lens is a concept that may also only apply at a specific aperture and at a specific area or point across the lens image plane.

No lens in the world is going to be 'sharpest' at every aperture and at every point across the film plane. They will only ever be 'sharpest' within a specific range of parameters - eg f8, in the centre of the frame, like the FA 100 Macro reviewed here:

Pentax Lens: Primes - Pentax 100mm f/2.8 Macro SMC P-FA (Tested) - SLRgear.com!

A review site like slrgear for example lets you visualise the issues of sharpness very well.

This may mean the 'sharpest' lens out there in Pentax land may get an absolutely stellar lph resolution in the centre of the image, but sharpness may drop away at the edges of the frame, and the peak sharpness may only come at f8-f11.

Which means if you were looking for the sharpest lens for use in general low-light street photography or sports photography, the 'sharpest' lens out there may not be useful to you at all because at f2.8 of f4 it may be only an average performer.

[SpecialK]

Dear All,

I am currently looking for the sharpest lens that can be mounted on a Pentax DSLR. There's no restrictions on what kind of lens as long as it is a DSLR pentax mount.

Prime or zoom, manual or auto focus, old or new, third party or genuine will do.

Admin if you could help me on the voting/counting.... would highly appreciate it.

Here's what i think for now since i don't have any sharp enough lens (for now).
(Currently own F 35-105mm, DA-L 18-55mm kit, M 50 f2)

1) Sigma 70 f2.8
2) Tamron 90mm f2.8
3) M 75-150 f4

If you can attached also sample pics from your lenses, would be great.

You are going to get 50 answers about 3 lenses :-)

[Digitalis]

"I'll also put in a plug for the M 50mm 1.7"

um, I must have a bad copy or something, but my 50mm f/1.7 gets its arse handed to it by the K 50mm f/1.2 at f/2.8 and up. The difference between the two is most apparent in the corners.

[JHD]

I have a number of Pentax and third party lenses, all of them currently available. Of the three you mentioned, I only have the Tamron 90; it's a nice lens but apart from macro duty, I really don't use it.

I've spent a lot of time looking at the Photozone MTF ratings and my take is for the best possible center sharpness at a reasonable price, the Sigma 30 1.4 has no equal. I have this lens and I wouldn't change it for the FA31. Sure it (the Sigma 30) isn't as sharp in the corners or the edges, but from what I can see it is considerably sharper than the FA31 in the center. In fact it is wicked sharp! I wish it was a little wider, but it is far more useful to me than my FA50, which unlike the Sigma 30 is very soft at F1.4. The other nice thing about the Sigma is images have a holographic 3 dimensional that rivals everything else I’ve seen, including my DA Limiteds.

My computer is mess but I'll look for something to post.

[JHD]

Uploaded with ImageShack.us

CLICK ON IMAGE TO SEE FULL SIZE

[JHD]

Uploaded with ImageShack.us

CLICK ON IMAGE TO SEE FULL SIZE

[fractal]

I've spent a lot of time looking at the Photozone MTF ratings and my take is for the best possible center sharpness at a reasonable price, the Sigma 30 1.4 has no equal.

It doesn't get mentioned often on here, but I really can't wait to own this lens. I quite like the FOV and from the samples i've seen the IQ looks great & not to mention really sharp in the centre.

[CWyatt]

I think there are perhaps issues with the question. As others have said, there are far more - or just as important issues are 'sharpness' in a lens. For a start, there is focal length and maximum apertures. Then size, weight, bokeh, focusing distances, focusing speed, build quality, rendering across the frame, rendering in the centre, vignetting, reliability, tendency for flare, tendency for fringing, colour, contrast, barrel or pincushion distortion, autofocus or manual, price, zoom range if any... etc etc. And sharpness at what aperture?

So do you need something along the lines of a Super Takumar 50mm f/1.4 manual, or a Pentax 100mm WR macro, or a 300mm DA*...

[feverbeaver]

The sharpest lens is the Leica 100mm 2.8 APO-Macro with leitax-adapter.
http://slrlensreview.com/web/leica-slr-lenses-133/macro-slr-lenses-141/418-l...ns-review.html

From Pentax it is the F/FA 50mm 2.8 Macro

[elho_cid]

Don't forget macro 50/2.8!
The DFA 50/2.8 is my sharpest lens (and I do not own just few of them).
I believe it has an edge over FA43 as well - but it is a close cut.

[8540tomg]

It doesn't get a whole lot of love but the sharpest lens in my kit is the old Pentax M 50/4 macro. Uber sharp and well correct for flatness of field. The Pentax A 100/2.8 macro is a close second. These are just personal impressions based on years of use and not Photozone MTF figures.

Tom G