[clackers]

Igor, the numbers you've crunched are about the owners, not the lenses themselves, psychological data rather than physical.

DxOmark had an old list of Pentax lenses with their highest scores. I can find it for you if you like.

[Douglas_of_Sweden]

The problem with lens reviews like the one on Pentax Forum is that most users only have experience of a small number of lenses. And people tend to like their gear, sometimes with passion. This causes a lot of 7th, 8ths and 9ths given to very average lenses that should have been given a 4, 5 or 6. So there is a lot of inflation in that rating system.

I have a little bit over 100 Pentax/Takumar prime lenses. Among those the best lense in my oppinion is the SMC Pentax A*135mm f1.8. The problem with its Pentax rating is that it is very rare, and therefore there are few reviews, so one very negative review is able to take down its average rating (it gets eleven 10ths, one 9th and one 3rd! That 3 value takes down the average from 9.92 to 9.38. In my oppinion, Adam should remove that review!). That review is either by someone who had a broken lens or did not undestand how razor thin the DOF is at 135mm f1.8 and hence failed to focus. His rating is enough to bring down the lense from the absolute top of average lens ratings. That is another weakness of that sort of rating system. Exceptional, but very rare lenses, becomes voulnerable to outlayer ratings. But I have this lens, and among its many fantastic properties, it is sharper wide open than any of the FA*-lenses, the A*85, FA*300, or any of the 35, 50 or 100mm macro lenses of Pentax that I have compared it with.

It is possible that the both A* and FA* 200mm macros might beat the A*135. But I don't have those lenses....still on the shopping list.

Neither do I have the 400 or 300/2.8s on your list. But the F*300/4.5 is optically the same as the FA*300/4.5, which I have, and that's also a very good lense that might belong in the top 10. The same applies to the DA35ltd macro, one of the best APS-C designs of Pentax. The K30/2.8 is a very nice lense, but it don't belong in the top 10. It has for some reason a very exclusive reputation, which elevates it above its actual (already good) quality.

A poll like tha one Adam made that elevated the FA77ltd, is in its nature partly a popularity competition. Lenses like the 200mm macros and the A*135 are too rare to show up there. It requires a lens that is both very goid (but not necessarily the best) and which sold well. That description fits the FA77ltd.

Fotnote: The FA77ltd, which didn't make it into the top 10 average ratings, uses the same optical design as the A*85, which made it into the top 10. They just tweaked focal length and speed slightly, which isn't a big loss, since the A*85/1.4 is soft wide open.

---------- Post added 10-10-17 at 11:50 PM ----------

In general though, there seems to be little relationship between price and quality as expressed by lens rating. That might not be surprising though, as no lens is rated below 7.7.

7.7! Well, there you have it. PFs lens reviews suffers as badly from inflation as I suffer from LBA. All these users who give their kit zoom 8 or 9 in rating... And equally bad: everyone who gives a 9 or 10 to the first full metall manual focus lens they hold, even if it's an average good mass produced 28, 50 or 135mm from the 70s. That's what gives us review ratings that appears to contradict themselves.

[leekil]

The FA77 got a 9.73! The #10 top lens above got a 9.76; it seems that is enough for margin of error...

But on the other hand, in order to get these 9+ ratings, many people must have given a 10! I am not entirely sure what it means for a lens to be a 10 -- absolutely perfect? And what if a better lens comes along later, well, I guess you can't give it more than a 10?

---------- Post added 10-10-17 at 03:39 PM ----------

When the DFA WR Limited primes come out, we'll have to make it go to 11!

[irek83]

I'm using F28mm f2.8, FA 43mm F1.9 Ltd, and FA 77mm F1.8 Ltd. All three lenses are just awesome but my best lens ever is FA 77mm F1.8 Ltd, this lens is just wow and gets a second breath on K-1. For walking I chose D-FA 24-70mm F2.8 with is superb walk around zoom lens.

I heard the best lens is lens which you have at the moment with you

[jddwoods]

I guess this more not just what is the best prime but the favorite. I have a bunch, all of the DA Limiteds, F 28mm f2.8, FA 50mm f1.7 and DFA 100 Macro WR. Out of what I have I would have to say its the DFA 100 macro WR. versatile as both macro and compact lightweight telephoto. If my DA 70 Limited didn't have so much wobble in the inner barrel, (lowers impression of build quality) I might call that my best prime. Its super sharp, in the same league as the DFA 100 macro and incredibly compact.

[monochrome]

Definitely the k 17/4 fisheye sorry no experience with most of the others..

It has become our nature to desire to measure, score, sort and rank anything and everything. Scoring, Sorting and Ranking are steps in Critical Thinking Theory. So we start with a:

• Standard, which are the characteristics we all agree are Good and none bad, but the
• Comparative has a Better presentation of those characteristics, so it is sorted to a higher rank, then
• Superlative, which is the Best example of the Standard, ranked the highest.

Unfortunately we don’t agree on Good, so we can never agree on Best. That’s why DxO is often consulted, yet often denigrated, and why a large number of quite different lenses achieve the same high PF Rating scores.

[photoptimist]

One way to deal with some of the weirdness of the relationship between price and ratings is to plot a scattergram of all lenses on price and rating and only look for lenses with the highest possible rating for a given budget or the lowest possible price for a given rating. That is:

1) What's the highest rated lens for under $50, under $100, under $200, and so on? Or:

2) What's the lowest cost lens that gets at least an 8.0, an 8.5, a 9.0, or a 9.5 rating?


(P.S. For nerds, this scattergram and the set of lenses with superior ratings for their price or superior price for their ratings is called the Pareto frontier in economics.)

[Adam]

It's official, the 77mm is best!

The FA 77mm Limited is the Greatest Pentax Lens - Pentax Lens Tournament | PentaxForums.com

[Ikarus]

Naw, that's not it...

Such a procedure won't change rank because there is no way for one lens to pass another, if you subtract the same number from all lenses, you maintain rank.

Well, let's just try, shall we? Previous first three:

1 SMC Pentax-M 50mm F2 8.22 24 (91) 2.92
2 SMC Pentax-A 50mm F2 7.84 34 (63) 4.34
3 SMC Pentax-M 50mm F1.7 9.38 41 (207) 4.37

Let's say the average lens rating is 8.22 (I don't actually know, I assume it's probably more around 8.5). After mean subtraction, the ranking according to the "mean-subtracted rating divided by dollars ratio" is:

1 SMC Pentax-M 50mm F1.7 +1.17 41 (207) 0.03

2 SMC Pentax-M 50mm F2 0 24 (91) 0

3 SMC Pentax-A 50mm F2 -0.38 34 (63) -0.01

Considering the other lenses on that list all have a rating above 8.22, the two 50mm F2 would actually end up all the way at the bottom. Makes a whole lot more sense like this.

[normhead]

Or on the flip side, if you need to take photo as quickly a possible, a zoom might cost you images because you might not be zoomed appropriately when you bring the camera to your eye.

Seriously?
My zoom covers 190mm a prime covers one.
The odds of a zoom being the right focal length? 190 more likely than the prime.
The odds that the zoom will be the right focal length? 190 times less likely than the zoom.

By agreeing to work in 10 mm changes we can cut the number of possible changes on the zoom, to say 19. 19 times more chance of success is nothing to sneeze at.

---------- Post added 10-10-17 at 09:39 PM ----------

Well, let's just try, shall we? Previous first three:

1 SMC Pentax-M 50mm F2 8.22 24 (91) 2.92
2 SMC Pentax-A 50mm F2 7.84 34 (63) 4.34
3 SMC Pentax-M 50mm F1.7 9.38 41 (207) 4.37

Let's say the average lens rating is 8.22 (I don't actually know, I assume it's probably more around 8.5). After mean subtraction, the ranking according to the "mean-subtracted rating divided by dollars ratio" is:

1 SMC Pentax-M 50mm F1.7 +1.17 41 (207) 0.03

2 SMC Pentax-M 50mm F2 0 24 (91) 0

3 SMC Pentax-A 50mm F2 -0.38 34 (63) -0.01

Considering the other lenses on that list all have a rating above 8.22, the two 50mm F2 would actually end up all the way at the bottom. Makes a whole lot more sense like this.

I have to admit, I have no idea what you are doing or why you are doing it. You lost me.

[monochrome]

FA50/2.8 Macro = 110 Lpmm @ f/5.6.

Done and Done.

[Kiwipixter]

I carry DA*55, DA 40 XS and DA 70 Ltd in the bag most of the time, the DA*55 is used and loved the most.

[jimr-pdx]

It has become our nature to desire to measure, score, sort and rank anything and everything. Scoring, Sorting and Ranking are steps in Critical Thinking Theory. So we start with a:

• Standard, which are the characteristics we all agree are Good and none bad, but the
• Comparative has a Better presentation of those characteristics, so it is sorted to a higher rank, then
• Superlative, which is the Best example of the Standard, ranked the highest.

Unfortunately we don’t agree on Good, so we can never agree on Best. That’s why DxO is often consulted, yet often denigrated, and why a large number of quite different lenses achieve the same high PF Rating scores.

'tis so. Each of us has our subset of gear and preference of what to shoot, and even two with identical gear will rate their lenses in different order. All answers are for entertainment value; I cannot imagine gleaning my ideal next lens from these chats. Still fun to chime in - though I doubt I've sold anyone on the K17

[Jonathan Mac]

I use the ratings as a quick guide if I find a lens for sale with the general rule that anything under 7.5 is not even worth considering. Beyond that, if I want to get an idea of how a lens performs I read the reviews and look for common praise and complaints.

Just as important as the rating itself is the number of reviews - a rating of ten with only one review has little validity, whereas a rating of ten from a dozen reviews carries a lot of weight. If ratings a have a wide spread rather than being similar it means there's either a lot of sample variation or a lot of variation in photographers and what they look for in a lens. Or a mix of both.

Lens ratings are really qualitative rather than quantitative if they're done by different people using different gear.

[Digitalis]

Lens ratings are really qualitative rather than quantitative

And some of them are weapons grade BS.

I absolutely hate questions like this, what is the best lens in X mount?

Sure the Pentax FA*200mm f/4 ED [IF] Macro is the "best" lens, sharp, contrasty - but I can't recall the last time I reached for a macro lens to photograph a landscape*. If you want the best 21mm lens, you will have to switch to Leica. If you want the best 800mm lens? You're going to have to get a Nikon.

All this scrabbling around for the Ne Plus Ultra of 35mm photographic optics can become spirit crushingly expensive, and wasteful. You really want my opinion? I think the SMCP-FA 31mm ASPH Limited lens is the best Pentax lens - why? it does everything well. Aside from some correctable CA issues, the lens can handle any subject matter you can throw at it and deliver an artful rendering of it.

* I'm not saying you cannot photograph a landscape with a 200mm lens. I have personally used 600mm lenses for such purposes, but there isn't much call for it.