[Eyewanders]

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Oh I never assume any excellent photo has not received pp... There is not an image I've ever released to a client that has not been touched at least in some way.

[civiletti]

PhotoZone rates optical quality of the DA15 as 3.5 stars and optical quality of the Samyang 14/2.8 as 4 stars. Make of that what you will.

[Wingincamera]

PhotoZone rates optical quality of the DA15 as 3.5 stars and optical quality of the Samyang 14/2.8 as 4 stars. Make of that what you will.

From my personal use, I will have to agree with PhotoZone. I plan on keeping my Bower 14mm for special occasions, but the Pentax 15mm is much easier to use & carry.

[Na Horuk]

Btw, I hope you've seen the '15mm controls my mind' club?

[todd]

Bear in mind, too, that distortion correction mushes the sharpness.
It's like the pixels object to being pushed around!

I am just a happy DA15 owner but this made me go look for some reading since I tend to push pixels around a lot.. So far this was a pretty good read and conversation about this subject: LensRentals.com - You CAN Correct It In Post, but . . .

[lytrytyr]

I'm not sure why people say that, it has no effect on the sharpness although of course certain features look different from being stretched, etc. (And you do lose a bit on the edges from the correction.)

@todd's post above gives a good reference for "why people say that".

The corrected images from the Samyang are on par with the 15 ltd or even better. Certainly there is less field curvature so it is much nicer for close-up subjects where the 15 ltd gives you soft edges. But it is more work.

Very often, field curvature can be an advantage,
when the objects at the edge are closer than the objects at the center.
As usual, it's a question of knowing your lens.

[Eyewanders]

I've changed my mind entirely: Pentax Zeiss Distagon 3 5 18mm T ZK Mount New Camera Lens Box Hood RARE F 18mm | eBay

[lytrytyr]

I've changed my mind entirely: Pentax Zeiss Distagon 3 5 18mm T ZK Mount New Camera Lens Box Hood RARE F 18mm | eBay

Doesn't your Ricoh GR cover that for you?

[Eyewanders]

Doesn't your Ricoh GR cover that for you?

Oh! My GR! Yes!
... now where is it?....

---------- Post added 02-19-14 at 09:11 PM ----------

Btw, I hope you've seen the '15mm controls my mind' club?

Dear Na Horuk,
I hate you a little bit right now.
Yours truly,
Kevin

[pinholecam]

DA15 Ltd for the size, starburst light source and flare resistance.
All things often never mentioned in lens reviews but play very importantly into a photographer's usage.

Samyang 14mm for the f2.8, FF, 14mm and price.

The Samyang gives the Nikon 14-24 a run for the money on FF.

[vonBaloney]

@todd's post above gives a good reference for "why people say that".

I invite you to correct images from the Samyang for distortion and identify any details lost from the uncorrected version (that aren't on the extreme edges where they just disappear). (And if you read the comments of the above listed article, much doubt is thrown on the case of resolution loss.) A bigger complaint that would be more accurate would be "once corrected, the lens isn't as quite as wide" which is very much true, whereas any difference in resolution is basically undetectable in real life images. In any case, "sharpness lost in correction" is certainly no reason to avoid the Samyang, whereas the fact of the extra work of fixing the distortion, or the size and weight of the thing, or the manual focus, or the difficulty in getting a well-calibrated copy, or the lack of ability to use filters all might be. I also don't like the what I think is the absurdly long focus throw for such a wide lens -- makes it harder to focus.

Very often, field curvature can be an advantage, when the objects at the edge are closer than the objects at the center. As usual, it's a question of knowing your lens.

Well, it might be an advantage in some scenarios, but "very often"? It is an annoyance more often than it is a benefit for most I think (or else the reviews would be filled with "the field curvature saved me again!" rather than "the field curvature can be troublesome"). Still a great lens though, and the usability factor remains much higher than the Samyang all-around. One can hardly go wrong with the 15ltd, but as a cheaper option the Samyang makes great images. (I thought slightly superior in my own side-by-side tests.)

[Na Horuk]

Dear Na Horuk, I hate you a little bit right now. Yours truly, Kevin

Thats why its a cult lens! Its a very different lens from the Samyang 14mm. Both are pretty great, but not interchangeable.

[lytrytyr]

And if you read the comments of the above listed article, much doubt is thrown on the case of resolution loss.

One comment (1/8/13) did actually mention the Samyang:

"I have a Samyang 14mm, a distortion champion. but also a lens with a remarkable resolution, out in to the most extreme corners. And correcting the distortion does sacrifice some of that resolution."

In actual practice, it's not a big deal, as you say,
but by the same token, it also means that measurebation results
do not provide a strong argument for preferring the Samyang over the DA 15.

---------- Post added 02-20-14 at 09:30 AM ----------

Well, it might be an advantage in some scenarios, but "very often"?

One typical case is when you're looking down on a flat plane.
The bottom edge of the image is then closer than the center.

[vonBaloney]

One comment (1/8/13) did actually mention the Samyang:

"I have a Samyang 14mm, a distortion champion. but also a lens with a remarkable resolution, out in to the most extreme corners. And correcting the distortion does sacrifice some of that resolution."

In actual practice, it's not a big deal, as you say,
but by the same token, it also means that measurebation results
do not provide a strong argument for preferring the Samyang over the DA 15.

Well, I don't think anyone was making that argument, but as also pointed out it is a flawed test because you're moving stuff around so the center is not the center anymore etc therefore the before and after resolution measurements are not of the same things. Again, feel free to actually compare corrected and uncorrected images for yourself as I have and show me where you lost any detail. It just isn't an issue -- at all. The entire problem with the distortion as I see it is simply that it needs to be done (most of the time) and so adds to the work of every image you want to use from the lens and you have to be aware when shooting that you are going to lose some around the edges altogether. But loss of resolution is simply a non-issue. And as I've said, the *corrected* images are superior to the 15ltd in sharpness (to my eye, not measured precisely), so loss of resolution even if it exists is no reason to prefer the 15ltd as it is still inferior in that department, not to mention a stop slower.

It should probably also be pointed out that while distortion on the 15ltd is much better-controlled, it is not perfect, so you'll often be applying corrections for that lens also if you have straight lines that you want to look absolutely straight. But you can get away with uncorrected much more often. I think it is a must to correct pretty much always on the Samyang.

[lytrytyr]

It should probably also be pointed out that while distortion on the 15ltd is much better-controlled, it is not perfect, so you'll often be applying corrections for that lens also if you have straight lines that you want to look absolutely straight. But you can get away with uncorrected much more often. I think it is a must to correct pretty much always on the Samyang.

Indeed.

One advantage that the DA 15 does have on a Pentax DSLR
is that you can have its distortion corrected in-camera,
assuming that your shooting needs allow for the time that takes.