[audiobomber]

I hadn't seen this discussed, so maybe others don't know. I just noticed that DXOMark has added tests of the 16-45, 18-250 and 55-300 to the previous tested Pentax lenses (18-55, 50-200, 16-50, 50mm macro). The old 16-45 is looking pretty good.

---

Last edited by audiobomber; 11-25-2010 at 01:08 PM.

[macTak]

Thanks for the heads up. The 16-46 looks nice indeed. I'm surprised to see the 55-300 not doing a little better against the 50-200. I can't say I like DXO's lens tests very much though--very hard to read (and their scores are completely useless).

[audiobomber]

I'm surprised to see the 55-300 not doing better (it's at best even with the 50-200). I can't say I like DXO's lens tests very much though--very hard to read.

I'm surprised at the 55-300 result too. I have an 18-250 and no way it's as good a lens as the 55-300, in ANY way other than wide angle coverage. To rate the 18-250 better as DXO has done is puzzling, but then I don't understand their tests. How do they rate lens sharpness using a single number? I'll have to do some research when I find time.

What I find interesting though, is comparing cameras plus lenses, which is not a feature anyone else provides. I compared Pentax lenses on the K20D to Canon and Nikon lenses on the 7D and D300, full-frame vs APS-C (wow, big difference) and Pentax lenses on K20D vs K10D. The last one was particularly interesting with all the talk lately about the K-5 vs K10D AA filters. The K20D shows higher resolution than the K10D, as you would expect. Unfortunately they haven't done lens tests with any camera newer than the K20D. It will be interesting to see where the K-5 lands with a possibly stronger AA filter and more resolution.

[macTak]

I'm surprised at the 55-300 result too. I have an 18-250 and no way it's as good a lens as the 55-300, in ANY way other than wide angle coverage. To rate the 18-250 better as DXO has done is puzzling, but then I don't understand their tests. How do they rate lens sharpness using a single number? I'll have to do some research when I find time.

I'd avoid that one number rating, and the resolution number (well for zooms anyway), and look at MTF in the resoluion tab. But I am confused by their MTF mesurements--is not the horizontal axis always the center to edge distance; whereas DXO is mesuring line pairs (and has seperate graphs for differect parts of the image). They call it "MTF per field position", so I think it's different from the normal MTF graph. But frankly, I'd have liked to be able to compare it with normal MTF charts. I can't quite visualise DXO's yet...