Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
09-11-2013, 05:45 PM - 1 Like   #1
Loyal Site Supporter




Join Date: Jun 2009
Location: Tumbleweed, Arizona
Photos: Gallery | Albums
Posts: 5,107
There is no perfect lens

Another one of Lens Rental's articles, based on their large inventory of lenses - and some extensive testing. An excellent read.


09-11-2013, 06:12 PM   #2
Pentaxian
Digitalis's Avatar

Join Date: Mar 2009
Location: Adelaide.
Posts: 8,792
But there are some lenses that come delightfully close to being optically perfect - though mechanical issues can occur with any lens if it abused enough.
09-11-2013, 08:30 PM   #3
Site Supporter
Aristophanes's Avatar

Join Date: Jul 2008
Location: Dartmouth, Nova Scotia
Photos: Albums
Posts: 3,922
camera obscura
09-11-2013, 10:38 PM   #4
Veteran Member
EarlVonTapia's Avatar

Join Date: Oct 2012
Location: Vancouver
Photos: Gallery
Posts: 1,152
I was going to post that article here, but glad that someone else did.

Roger Cicala does it again. A fantastic article, and a fabulous weapon to use against the argumentative lens nerd set.

09-11-2013, 11:22 PM   #5
Site Supporter
Douglas_of_Sweden's Avatar

Join Date: Apr 2008
Location: Stockholm
Photos: Gallery
Posts: 3,353
To begin with, it is impossible to make a "perfect lens" because we insist on projecting the image on a flat surface.
09-12-2013, 07:59 AM   #6
Senior Member




Join Date: Aug 2012
Location: Doylestown, PA
Posts: 200
A good read.

I may have to bookmark the LensRentals blog. They do a good job with these article style posts.
09-12-2013, 09:17 AM   #7
Veteran Member
EarlVonTapia's Avatar

Join Date: Oct 2012
Location: Vancouver
Photos: Gallery
Posts: 1,152
QuoteOriginally posted by thornburg Quote
A good read.

I may have to bookmark the LensRentals blog. They do a good job with these article style posts.
You may be interested in the story behind LensRentals.com.

https://www.pentaxforums.com/forums/general-photography-industry/231599-story...ntals-com.html

09-12-2013, 10:19 AM   #8
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 25,809
Now you can see why results from sites like Photozone and Imaging Resources and DxO have such a hard time producing consistent results. Any site that tests on less than 10 lenses isn't going to be able to provide estimates on sample variation, and without that their results are not at all scientific. When they do get good results they can pretty much guarantee you that it's possible you might get good results, but they can't guarantee you won't get a bad sample. When they get a bad sample, they can't guarantee you that your results won't be a lot better. And if they ended up with a poor sample, then they could do a great disservice publishing their review. Read those testing sites with caution and a healthy degree of scepticism. That was recently highlighted on one site when the same lens test on a Pentax system tested 20% worse than it did on a Nikon system. K-5 and D7000.

Before those sites mean anything , they will have to give you the bottom score and the top score for a series of test lenses with the average deviation from the norm. Then you'll be able to evaluate the risk of buying said lens, and understand the likely hood that you will have to return it for a better copy.

09-12-2013, 12:07 PM   #9
Pentaxian
Lowell Goudge's Avatar

Join Date: Jan 2007
Location: Toronto
Photos: Gallery | Albums
Posts: 15,400
The real point, I think of the article is that the lens manufacturers do a dam good job of delivering a remarkably complex component at a fair price and reasonable quality

And in reality, who really cares about how well a lens reproduces a lens chart. I do now know a single photographer who has won an award with a photo of a lens chart, unless you capture it spectacularly on fire, which by the way is an excellent use for a lens chart IMO, no one except labs and photo magazines ,make any money photographing lens charts.

There is no point complaining about the fact we project images onto flat surfaces, because most subjects are not flat either , so who the hell cares!

In addition, since none of our subjects are perfect, why should the equipment we use be expected to be?

Lenses have always been, and always will be, just tools, knowing what to do with a lens, flaws and all, is what makes a photographer!
that's all!
GOT IT!
09-12-2013, 01:04 PM   #10
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 25,809
QuoteOriginally posted by Lowell Goudge Quote
The real point, I think of the article is that the lens manufacturers do a dam good job of delivering a remarkably complex component at a fair price and reasonable quality

And in reality, who really cares about how well a lens reproduces a lens chart. I do now know a single photographer who has won an award with a photo of a lens chart, unless you capture it spectacularly on fire, which by the way is an excellent use for a lens chart IMO, no one except labs and photo magazines ,make any money photographing lens charts.

There is no point complaining about the fact we project images onto flat surfaces, because most subjects are not flat either , so who the hell cares!

In addition, since none of our subjects are perfect, why should the equipment we use be expected to be?

Lenses have always been, and always will be, just tools, knowing what to do with a lens, flaws and all, is what makes a photographer!
that's all!
GOT IT!
exactly, there is nothing on a lens chart that explains why I like the images from my 21 Limited so much, to the point that I use 21limited as my nick on other forums.

21 limited: not the sharpest lens in the bag, but sometimes it takes a totally awesome picture.
09-12-2013, 03:19 PM   #11
Veteran Member
carrrlangas's Avatar

Join Date: Mar 2012
Location: Joensuu (Finland)
Photos: Gallery
Posts: 1,748
QuoteOriginally posted by normhead Quote
21 limited: not the sharpest lens in the bag, but sometimes it takes a totally awesome picture.
I beg you, stop praising this lens. I just got the DA40xs and love the size, focusing speed and handling... If there only was a XS version of the 21 for my student budget...

On the topic: Great read. Amazing work behind this article for sure.
I just started a course on Optical engineering (I am an electronics engineering student, optics go from imagery and video to optoelectronics, lasers, optical fiber, etc) and we saw simple lens designs as an introduction and when the most common lens aberrations where explained I noticed that you canīt control all of them at the same time. You must make compromises depending on application. So, thereīs always a tradeoff between them.

If I used my equipment for something else than my enjoyment, Iīd surely send the hole system in for calibration and check... I know it was done with film SLR / rangefinders systems
09-12-2013, 08:13 PM   #12
Pentaxian




Join Date: Jun 2008
Location: Flyover America
Posts: 4,475
QuoteOriginally posted by interested_observer Quote
There is no perfect lens
There is no "perfect".
09-13-2013, 04:55 AM   #13
Site Supporter
Aristophanes's Avatar

Join Date: Jul 2008
Location: Dartmouth, Nova Scotia
Photos: Albums
Posts: 3,922
QuoteOriginally posted by Aristophanes Quote
camera obscura
There is no lens.

Sad to quote myself. <shame>
09-13-2013, 05:25 AM   #14
Veteran Member




Join Date: Dec 2010
Location: Central Kentucky
Photos: Gallery | Albums
Posts: 1,415
QuoteOriginally posted by carrrlangas Quote
I beg you, stop praising this lens. I just got the DA40xs and love the size, focusing speed and handling... If there only was a XS version of the 21 for my student budget...

Same route I went. Love the 40 but it is the 21 I am having a torrid affair with. It is only a matter of time until you succumb.
09-13-2013, 05:40 AM   #15
Pentaxian
normhead's Avatar

Join Date: Jun 2007
Location: Near Algonquin Park
Photos: Gallery | Albums
Posts: 25,809
QuoteOriginally posted by carrrlangas Quote
I just started a course on Optical engineering (I am an electronics engineering student, optics go from imagery and video to optoelectronics, lasers, optical fiber, etc) and we saw simple lens designs as an introduction and when the most common lens aberrations where explained I noticed that you canīt control all of them at the same time. You must make compromises depending on application. So, thereīs always a tradeoff between them.
It is amazing how many lens "experts" we have on here who have never taken a course in lens design. Who argue that they understand everything about lenses because they studied optical physics etc. As in many things , understanding the physics doesn't necessarily mean you understand the problems of turning out a practical application.

It leads to a lot hot air being blown around.
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!
k-mount, lens, pentax lens, slr lens
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
People When there is no XBOX daacon Post Your Photos! 9 03-03-2012 07:56 AM
Genesis 1 if there is no God... JohnBee General Talk 64 01-20-2012 08:24 PM
Why there is no 3rd party WR lens? ducdao Pentax DSLR Discussion 17 12-08-2011 03:45 AM
Why there is no Zeiss K-mount lens in lens database henryjing Pentax SLR Lens Discussion 3 05-18-2010 01:39 AM
Why there is no zoom lens below f/2.8? Karellen Troubleshooting and Beginner Help 34 03-03-2010 10:06 AM



All times are GMT -7. The time now is 06:19 AM. | See also: NikonForums.com, CanonForums.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