Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
12-21-2011, 10:28 PM   #16
Veteran Member




Join Date: Feb 2010
Photos: Gallery | Albums
Posts: 971
The 40mm f2.8 is the best bang for your buck lens in all of Pentax modern lenses.

12-21-2011, 11:38 PM   #17
Veteran Member
causey's Avatar

Join Date: Feb 2009
Location: Arlington, VA
Photos: Albums
Posts: 3,758
QuoteOriginally posted by Docrwm Quote
Now, the next question (which is also subjective) is: Is it worth 2.25 times the cost of the DA35/2.4?
Yes, I think so: much better microcontrast (area in which ltds. excel), metal construction (we'll see about the durability of the DA 35/2.4 plastic mount after a few years of usage), diminutiveness (one may call it sexiness).

QuoteOriginally posted by Eagle_Friends Quote
The 40mm f2.8 is the best bang for your buck lens in all of Pentax modern lenses.
+1

Last edited by causey; 12-22-2011 at 12:01 AM.
12-22-2011, 05:48 AM   #18
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
Original Poster
QuoteOriginally posted by RioRico Quote
Our ratings result from emotional and financial involvement, not just-the-facts-ma'am objective measurements. Ooh, it was expensive, it must be good! Ooh, it was really cheap, such a deal! But we can hopefully draw statistically significant conclusions with a large enough sample size. The fewer the reviews, the larger the grain of salt.
Exactly. The n here is ~40 per lens. Anyway, everyone thinks they can eyeball the #s or that stats are intuitive enough that they can wing it.
12-22-2011, 06:40 AM   #19
Pentaxian
mikeSF's Avatar

Join Date: Jan 2009
Location: East Bay Area, CA
Photos: Gallery
Posts: 5,519
QuoteOriginally posted by Docrwm Quote
... The highest rated lens also happens to be the most expensive lens on the list as well. Cognitive dissonance theory would tell us that the cost is why the rating is the highest. People rate things higher that cost more and there are loads of ways this has been demonstrated over and over again (e.g., same radio, same description, two groups, only difference is the cost attributed to the radio, more expensive is rated as a great radio, less expensive as a piece of junk).

interesting finding and thanks for your study of this.

I actually tend to behave oppositely. when considering a lens review, i score largely based on my perceived value of the lens. That is, if there is a strong performer that only cost me $40, i am generally going to conclude that it presents a better value than perhaps a somewhat better performing lens that cost me $500. You can bet when i pay $500-$1000 for a lens i am going to be super picky about its every attribute.

12-22-2011, 06:57 AM   #20
Pentaxian
hoanpham's Avatar

Join Date: Nov 2009
Location: Strand
Photos: Gallery | Albums
Posts: 1,360
QuoteOriginally posted by mikeSF Quote
I actually tend to behave oppositely. when considering a lens review, i score largely based on my perceived value of the lens. That is, if there is a strong performer that only cost me $40, i am generally going to conclude that it presents a better value than perhaps a somewhat better performing lens that cost me $500. You can bet when i pay $500-$1000 for a lens i am going to be super picky about its every attribute.
So all lenses I got for free should have 10 in rating?
How would you rate the FA85/1.4? This lens is superb for portrait distance, but very poor in longer distance, and still count as must-have even it costs more than 1200 usd used.
Lens reviews are based on personal perception. Without mention the reason and scale, it can only serve as guideline.
12-22-2011, 07:03 AM   #21
Veteran Member
creampuff's Avatar

Join Date: May 2007
Location: Singapore
Photos: Gallery
Posts: 3,955
QuoteOriginally posted by Marc Sabatella Quote
I don't think so. The fact it is the cheapest of the Limiteds, and also one of the most useful lengths, means it is for many people their first and only prime. So many DA40 owners are comparing only to the kit lenses. On the other hand, also consider that the differences in average ratings for these lenses is probably not statistically significant.
QuoteOriginally posted by dgaies Quote
It's not just a matter of whether they are statistically significant. The same people are not rating each of these lenses, nor do individuals rate things on the same scale. As Marc pointed out, it's entirely conceivable that a large number of the people rating the DA40 might have a different perspective than those rating the FA31. Bottom line, I would take the numerical ratings with a huge grain of salt and use the reviews as a general guide for how people feel about a certain lens.
Very cogent points.
The fact is trying to attribute some kind of correlation between subjective quality ranking and price is fraught with flawed assumptions and potential errors.
Every lens is different and everyone has their own assessment whether it offers the most bang for the buck.
12-22-2011, 07:04 AM   #22
Veteran Member
vrrattko's Avatar

Join Date: Jun 2010
Photos: Albums
Posts: 734
As others mentioned before....those numerical ratings aren't really a reliable source, but reading what people actually write about the lens is bit more useful. As an example when I first wrote a review for my FA77, i was totally delighted with it so I saw it as a straight 10 rating. The only comparable lens I had tried before I got 77 was Sonnar 85. But then I was lucky to own other lenses like DA70, A100/2.8, K105 and eventually I realized that all those lenses are strong performers and not much worse (if at all) than FA77 and therefore I revised my rating for FA77.
Now across the Pentax lineups you can find plenty of lenses which could chalenge limiteds, somebody mentioned K28/3.5, K35/3.5....from my own experience I can add K20/4, FA20/2.8 (I never handled DA21 so no direct comparison here but several members of this forum did the comparison and by their measures they valued older lenses better), FA50/1.7, FA35/2 and K35/3.5....
and Limiteds I had: FA31, FA77 (gone) and FA43, DA70 (those 2 I kept)
12-22-2011, 07:06 AM   #23
Loyal Site Supporter




Join Date: Jul 2010
Location: Blue Ridge Escarpment, North Carolina, US
Photos: Gallery | Albums
Posts: 1,282
QuoteOriginally posted by RioRico Quote
Our ratings result from emotional and financial involvement, not just-the-facts-ma'am objective measurements. Ooh, it was expensive, it must be good! Ooh, it was really cheap, such a deal! But we can hopefully draw statistically significant conclusions with a large enough sample size. The fewer the reviews, the larger the grain of salt.
Rio,
Dumpster Diver philosophical directive: Cheap+deal+unusual+need fulfillment+perceived quality=Gloat
For many, the hunt is as important as the acquisition and usage of said tool.
The fact that the Pentax community offers constructive reviews affirms your grain of salt comparison.
Always enjoy your commentary.

12-22-2011, 07:14 AM   #24
Pentaxian
mikeSF's Avatar

Join Date: Jan 2009
Location: East Bay Area, CA
Photos: Gallery
Posts: 5,519
QuoteOriginally posted by hoanpham Quote
So all lenses I got for free should have 10 in rating?
...
if you say so. i never said that.
that said, $25 for a 40 yr old helios 44-2 that requires a screwmount adapter, has old coatings, produces odd swirly bokeh at times, and may not be the sharpest lens in the box...is a no brainer must buy lens, IMO. It makes gorgeous photos, IMO. These comparisons are really THAT subjective at times. I recently spent $900+ for an FA31; you can bet if the aperture blades were not perfectly symmetrical at every stop, i'd be grumbling over that and my score would reflect it.


QuoteOriginally posted by hoanpham Quote
How would you rate the FA85/1.4? This lens is superb for portrait distance, but very poor in longer distance, and still count as must-have even it costs more than 1200 usd used.
again, the ratings will always be subjective. If i bought such a lens only for the purpose of shooting close portraits, i might love the performance and not care if it fails for tele shots. if i bought it for teles and all my experience with it were in shooting teles, well i'd likely rate it as a dog. hopefully people are reading the actual text to the reviews and not just the scores. If i see a review from someone whose work i greatly respect, their review is solid as far as i'm concerned. For example, when i see the jsherman999, peter zack, simon, axl, riorico, rparmer, etc, etc stamp of approval, that's all i need.

Last edited by mikeSF; 12-22-2011 at 07:27 AM.
12-22-2011, 07:26 AM   #25
Veteran Member
macTak's Avatar

Join Date: Apr 2010
Photos: Gallery
Posts: 759
I think RioRico said a very nice bit. I'm inclined to think there is a non-objective component to lens reviews. I'm not entirely convinced it has to do with price, so much as cachet. I think highly-regarded lenses put people on a more favourable disposition to begin with (and many lenses we have to choose from are so good anyway this can make a difference in how hard we search for flaws, etc), as well as making them less inclined to go against the perceived wisdom. To me, the most interesting lens-rating case is of the 55mm Takumar and SMC-K lenses. The f1.8 and f2 models have the same optics, the only difference is an internal restriction on maximum aperture in the f2 lens (and f1.8 vs. f2 is a rather trivial difference for actual images). So, they should have about the same rating (price-wise, both are cheep and there isn't much difference to affect things). However, the scores for the f1.8 lenses are 9.33 and 9.37; whereas, the scores for the f2 lenses are 8.36 and 8.60, respectively. Perhaps, instead, it comes down to what kind of person would buy the highly regarded 55/1.8 over the less-known and regarded 55/2.
12-22-2011, 07:50 AM   #26
axl
Veteran Member




Join Date: Mar 2007
Location: Nove Zamky, Slovakia
Photos: Gallery | Albums
Posts: 7,181
As many others have said, numerical evaluation of lenses is very dodgy. You have to see few facts behind it, such as: what other lenses has the reviewer compared it to. For someone shooting low end FA zooms, or low end 3rd party lenses any Ltd or * lens will be straight 10. But when you start comparing them to each other you'll start seeing minute differences that may (or may not - personal choice) matter a lot.
Personally, I've tried (owned) FA31, FA43 (4 copies), FA77, DA40, DA*50-135, FA*28-70, FA*24, FA*300/4.5 and DA*55, and I've tried (only tried) DA*200 and FA*80-200.

The best bang for the buck? DA40 easily! That lens deserves as much praise as one can sing! The only "negative" is f2.8 only and that's why I sold it when I got 43. The underdog of the bunch? DA*55, with all that rubbish written about it's AF and it's price tag, this lens is often overlooked, but for certain applications it beats FA43 or FA77 with breeze. The ones I didn't care too much for: FA31 and 77. Techincally they are excellent but I never got the hang of framing with those FOVs.
The overall winner?...FA43 for me, despite selling it I keep coming back to it. It's small, fast enough for most application, delivers excellent IQ and used ones go quite cheap these days.

My 2p
12-22-2011, 07:52 AM   #27
Loyal Site Supporter
baro-nite's Avatar

Join Date: Aug 2011
Location: North Carolina, USA
Photos: Gallery | Albums
Posts: 4,298
QuoteOriginally posted by macTak Quote
ITo me, the most interesting lens-rating case is of the 55mm Takumar and SMC-K lenses. The f1.8 and f2 models have the same optics, the only difference is an internal restriction on maximum aperture in the f2 lens (and f1.8 vs. f2 is a rather trivial difference for actual images). So, they should have about the same rating (price-wise, both are cheep and there isn't much difference to affect things). However, the scores for the f1.8 lenses are 9.33 and 9.37; whereas, the scores for the f2 lenses are 8.36 and 8.60, respectively.
Given your view that f/1.8 vs. f/2 is trivial, it's no surprise you would expect the two lenses to be about the same quality/value. But I think most people have a different threshold for what constitutes a significant difference in lens speed, and I think this is just enough of a difference to matter. That said, for two lenses that share the same optical formula, I agree that the ratings difference seems exaggerated. Especially when you look at the respective ratings for the various categories -- sharpness and so on.

QuoteOriginally posted by macTak Quote
Perhaps, instead, it comes down to what kind of person would buy the highly regarded 55/1.8 over the less-known and regarded 55/2.
I very much doubt one could discover such "types". But this difference is intriguing. I think this is more likely a function of how pre-conceived notions affect judgment. The f/2 version was the cheaper lens in its day, so it must be inferior, right?
12-22-2011, 10:19 AM   #28
Veteran Member
Docrwm's Avatar

Join Date: Sep 2010
Location: Somewhere in the Southern US
Photos: Gallery | Albums
Posts: 11,275
Original Poster
QuoteOriginally posted by mikeSF Quote
interesting finding and thanks for your study of this.

I actually tend to behave oppositely. when considering a lens review, i score largely based on my perceived value of the lens. That is, if there is a strong performer that only cost me $40, i am generally going to conclude that it presents a better value than perhaps a somewhat better performing lens that cost me $500. You can bet when i pay $500-$1000 for a lens i am going to be super picky about its every attribute.
I agree with that approach and use it myself. The newly added extra dimensions in the Lens Review section includes a "Value" score. I based my #'s in this thread on the older (and still the predominant) number based on one summary score for each review per lens which would include a variety of factors.

Aggregate scores across sufficient reviewers do yield meaningful results and differences. Its entirely possible to point to a single review, or a cluster, and find exceptions. However, we're talking about populations not individuals when we look at scores over 40+ reviewers across many lenses. Its like the old woman that when told that 15% of people have warts says she doesn't know anyone with a wart. Doesn't change one whit that the original statement is true and accurate. Same for subjective ratings, you just need more #s and clearer differences.

Thanks for the thoughts.

Last edited by Docrwm; 12-22-2011 at 10:24 AM.
12-22-2011, 11:06 AM   #29
Veteran Member
RioRico's Avatar

Join Date: Jun 2008
Location: Limbo, California
Posts: 11,264
QuoteOriginally posted by causey Quote
(we'll see about the durability of the DA 35/2.4 plastic mount after a few years of usage)...
Have you any evidence that polycarbonate (Lexan) mounts are less durable than metal mounts?

I see many review dings of lenses with polycarbonate construction because of their build and feel, not their optics and performance. The FA100-300 (silver) is one such. Mine is over 20 years old, works like a charm, shows no mount wear -- and would probably withstand more punishment than a metal-body equivalent. I'll argue that because polycarbonate-build lenses are under-scored, they're better deals than higher-rated metal-build glass.

Polycarbonate is not polystyrene. Not all plastics are created equal. Metal dents; plastic bounces.

QuoteOriginally posted by lukulele Quote
Always enjoy your commentary.
Thank you, thank you.

[/me humbly burnishes fingernails on sleeve]
12-22-2011, 12:40 PM   #30
Site Supporter




Join Date: Jan 2011
Location: Charleston, SC
Photos: Albums
Posts: 347
DA40 is pure magic. IMHO it is 2x better than the DAL35.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
cost, k-mount, lens, lenses, limiteds, pentax lens, radio, ratings, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
AFTER QADDAFI: Oil Prices Will Tank, Stock Prices Will Soar jogiba General Talk 10 08-23-2011 05:08 PM
Pentax APS-C Lenses Prices and Reviews rm2 Pentax SLR Lens Discussion 9 11-15-2010 01:41 AM
Pentax lenses prices Andrzej Pentax SLR Lens Discussion 18 02-26-2010 09:58 AM
Prices for new DA lenses ogl Pentax News and Rumors 24 01-29-2008 11:01 AM
My Subjective Ratings on Pentax Lenses on Pentax DSLRs RiceHigh Pentax SLR Lens Discussion 8 02-20-2007 10:18 PM



All times are GMT -7. The time now is 08:23 AM. | See also: NikonForums.com, part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top