[btnapa]

People taking DxO as the final truth is just scary.

Best lenses for the Pentax K-3 according to DxO.

Sigma 35 ƒ1.4-- ya right , a big favourite here on the forum. Funny how the fastest lenses always come out best in the DxO ratings. not mentioned in the DxO ratings 31 ltd, 43 ltd and 77 ltd. simply some of the finest lenses ever produced. According to DxO mark the Sigma 35 gives you 2x the megapixels of a DA 15. Ya right, I believe that.


Good luck waiting for DxO to test the 24-70. I've had my 60-250 for close to four years now, and they still haven't tested it. Thinking like you, would have missed a lot of great images.

Compared to sites like IR, the warped rating system which truly can't be comprehended, the lack of lenses tested, and the way they inflate the differences between lenses to an outrageous level, they are truly the drama queens of the testing world.

Norm,

I don't know why DXO is so down on Pentax lenses. I generally think they are on the mark with most of the lenses they test. If I had to go by their ratings for Pentax glass, I would have thought that Pentax makes garbage for lenses. Being a Pentaxian and owning the Three Amigos and a few 645 lenses, I begin to doubt the DXO ratings. The Three Amigos, along with great majority of Pentax lenses, are some of the finest in the world. Why, because I own a few and I know first hand they produce fantastic images on my K3. I can't wait to see how these puppies perform on the full frame. BTW, the same applies to Pentax 645 glass. They are compared to much more expensive Leica and Hassy glass and they hold up pretty good against lenses costing many time more than the typical Pentax 645 glass.

[normhead]

It's pretty simple, they do not test their theory of lens rating against any kind of real world standard, like people's enjoyment of the images produced.

Tess once took a picture with her point and shoot 10 MP camera, that we eventually sold 3 times, printed at 20"x 30" for almost $900. There is nothing on the DxO website that explains how that is possible.

[btnapa]

It's pretty simple, they do not test their theory of lens rating against any kind of real world standard, like people's enjoyment of the images produced.

Tess once took a picture with her point and shoot 10 MP camera, that we eventually sold 3 times, printed at 20"x 30" for almost $900. There is nothing on the DxO website that explains how that is possible.

Now that you mention it, I shot a covered bridge back in 2000. It was shot with a Fuji S1 (3MP and no RAW support). It was a JPEG image that I enlarged to a 20X30" as a set of sepia tone images. I sold a set at that size. In honesty, the image will have so much more detail if I shot it with my K3 but it was presentable as it was too.

[Rondec]

Norm,

I don't know why DXO is so down on Pentax lenses. I generally think they are on the mark with most of the lenses they test. If I had to go by their ratings for Pentax glass, I would have thought that Pentax makes garbage for lenses. Being a Pentaxian and owning the Three Amigos and a few 645 lenses, I begin to doubt the DXO ratings. The Three Amigos, along with great majority of Pentax lenses, are some of the finest in the world. Why, because I own a few and I know first hand they produce fantastic images on my K3. I can't wait to see how these puppies perform on the full frame. BTW, the same applies to Pentax 645 glass. They are compared to much more expensive Leica and Hassy glass and they hold up pretty good against lenses costing many time more than the typical Pentax 645 glass.

DXO Mark scores look at sharpness (both maximal and wide open) and light transmission for the most part. The reality is that most APS-C lenses of similar aperture score pretty similarly. The same with full frame lenses.

Pentax makes a lot of their lenses slower than the competition and that makes them look not as good as the competition.

I do think the DXO Mark lens scores are a pretty misunderstood thing and not terribly helpful in really world evaluation of a given lens.

[normhead]

I sold a set at that size. In honesty, the image will have so much more detail if I shot it with my K3 but it was presentable as it was too.

The question that really stands out here though, is , would the people who bought the picture have enjoyed it more at a higher resolution? Resolution is not synonymous with a higher level of satisfaction from the viewers end. That is the assumption made over and over in the posts, and it has absolutely not one bit of credible evidence to support it. What you have is a bunch of people looking at images from 8 inches away saying "this one has more resolution" as if that meant from 5 feet away, anyone would be able tot tell the difference. As far as I know that's never been done. And where people have done images printed at 72 DPI were pretty much even with images printed at 150 dpi with the actual numbers being split so even you couldn't say for sure, people could tell the difference.

This is one guy's class room experiment, everyone else has nothing.

[stevebrot]

I know this is a Pentax biased forum (in the nicest possible way!) so it might not be seen as the best place to read impartial reviews...

The interesting thing is that many (most?) of the users here are fairly "lens agnostic" with the possible exception of the FA Limiteds.


Steve

(...doesn't own a lot of Pentax glass...)

[stevebrot]

I don't know why DXO is so down on Pentax lenses.

They apply an arbitrary bias to the score based on format and pixel count that tends to down rate mounts that are either intended for or limited to cropped formats. The intent is to allow cross-brand and cross-format comparisons in a world where such is not meaningful nor really truly possible. The result is a general downgrade of lenses limited to cropped-sensor cameras. That is why I like the reviews at photozone.de where Klaus is quite explicit in his caution that Imatest results should not be compared between sensors.


Steve

[noelpolar]

Quite simply there isn't a perfect review or rating system

Not true. My wife is quite insistent (and confident) in her husband review and rating system.... quite similar to DXO really.

I basically come out as a FA lens..... you know..... needs new coatings, updated body and faster drive motor.... (actually I lied.....I'm more of a SMC K* these days..... plus a bit self delusional)

*Anna pushes the AF button and I just sit there....... wondering what all the fuss is about.

[monochrome]

Not true. My wife is quite insistent (and confident) in her husband review and rating system.... quite similar to DXO really.

I basically come out as a FA lens..... you know..... needs new coatings, updated body and faster drive motor.... (actually I lied.....I'm more of a SMC K* these days..... plus a bit self delusional)

*Anna pushes the AF button and I just sit there....... wondering what all the fuss is about.

Sure - but she should always remember you came with Push Button exposure management so you'll never embarrass her in front of her friends and In-Body Inhaling Stabilization so she can sleep through the night without having to elbow you onto your side.

[Rondec]

I guess I would just say that overall, I do find reviews that do some testing of distortion/vignetting, but also have real world examples of things like flare are handy. Most modern lenses are pretty sharp stopped down a stop, some are sharp wide open.

My experience with the DFA 24-70 has been good, but it certainly is mostly composed of real world images without any test charts.

[pathdoc]

DxO seem to have at least a standardised approach to what they put their lenses through - my issue lies with what they do to the data afterwards. The more massaging, the less I trust the final result, to the point where after a while the "wet finger in the wind" numbers generated in the user reviews here - combined with the more detailed subjective descriptions of how the lens has behaved in the user's possession - are probably more useful.

This is in part why I gravitate towards older glass - the longer a user has had it and shot with it, the more meaningful I think the scores they assign to it are, particularly when they admit to the lens's limitations as well as sing its praises.

[kenspo]

I did a Valentine shoot in studio with the 24-70 last month. Will do a deeper feedback when i have the time and used it enough with the FF. But you can see the sharpness. This lens is stunning!!! Shot with the K-3 II

[Paul the Sunman]

February 10 and still no user review of the 24-70 on B&H. Does that mean it's not selling?

[Digitalis]

My problem is acquiring multiple copies of these lenses so I can have an adequate sample size to draw any reasonable conclusions. The sample variation with the Canon and Nikon 24-70mm f/2.8 lenses is horrendous. For the love of god pentax, get your QC straight.

[Rondec]

February 10 and still no user review of the 24-70 on B&H. Does that mean it's not selling?

I certainly think sales have not been great. My expectation is that once the full frame camera is released, that we will see sales of this lens pick up. The focal length fits full frame shooting better than crop shooting, although clearly it can and will be used on both sensor sizes/. (I also went ahead and added my review to the B and H page)...