Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-06-2016, 12:54 PM   #16
Loyal Site Supporter
clackers's Avatar

Join Date: Jul 2013
Location: Melbourne
Photos: Albums
Posts: 9,022
QuoteOriginally posted by Yassarian Quote
. Yet, seems like all the sharper lens are made by 3rd party?
Who said that?

Not me ... I gave you five Pentax lenses as examples, all that will work great on their first-ever full frame body.

If you're a pixel peeper, you already have the 100, now go buy the other four. ;-D

05-06-2016, 01:54 PM   #17
Pentaxian
RonHendriks1966's Avatar

Join Date: Jan 2009
Photos: Gallery
Posts: 8,714
Well the test shows that you can buy the 645Z and be better off then with the D810.

Wel the 77mm is an a-grade lens costing almost $800. So you have to expect it to work. I think it even does, as being a portrait lens. Pentax doesn't offer a regular 85mm lens. This is by the way a choice that Pentax made. They probably could have worked with Tamron and offer the new 85mm/F1.8 from Tamron in a Pentax coat just as with the zoomlenses. But they didn't. Does the 77mm lens meet the expectations of the non-Pentax crowd? Probably not, but that is something Ricoh has to live with.

Just be happy they didn't use the FA 43mm lens for this test.

Last edited by RonHendriks1966; 05-06-2016 at 02:25 PM.
05-06-2016, 02:13 PM - 2 Likes   #18
Pentaxian




Join Date: Jun 2009
Location: GMT +10
Photos: Albums
Posts: 10,843
DPR have a strange habit of making poor lens choices to use on their review Pentaxes. The old M 50 f2 they put on the K-1 in their preview springs to mind. And now using the FA 77 as the studio test lens?

As others have noted, they should have (like Imaging Resource's use of the Sigma 70mm macro) used a macro lens that it available at the same focal length for all mounts. The uniqueness of the FA 77's focal length, and it's design goals as a portrait lens, make it's selection as a lab test lens really bizarre.

Last edited by rawr; 05-06-2016 at 02:20 PM.
05-06-2016, 02:30 PM   #19
Pentaxian
Pål Jensen's Avatar

Join Date: Dec 2007
Location: Norway
Photos: Albums
Posts: 3,148
There's nothing wrong with the 77 Limited. It is one of best lenses money can buy....

05-06-2016, 03:16 PM - 1 Like   #20
Loyal Site Supporter
clackers's Avatar

Join Date: Jul 2013
Location: Melbourne
Photos: Albums
Posts: 9,022
Yep, a bad copy is a bad copy. These magazines all suffer from doing reviews of a sample size of one. Lens Rentals like to look at ten or more, to take into account sample variation.

No editor wants to hear that of course.
05-06-2016, 03:28 PM   #21
Veteran Member
jsherman999's Avatar

Join Date: Dec 2007
Photos: Gallery
Posts: 8,228
QuoteOriginally posted by btnapa Quote
...Today I tried my FA 77 at f8 to see more of what a "better" lens can do. For the fun of it I also shot the same thing at 200mm with my Tamron 70-200. Boy did I get a big surprise. In the corner of the image the Tamron at 200mm at f4 is visibly sharper than the mighty FA77 at f8. I know this was not a scientific test so I do not want to draw any final conclusion.
btnapa, you compared two different focal lengths from the same position, or moved back with the Tamron at 200 to preserve the framing? Neither is apples-apples.

I owned a perfect copy of the Tamron 70-200, and my 77 was sharper than the Tamron at 77mm through the entire shared aperture range (f/2.8+) I think I had a thread here where I compared my new tamron to a couple primes at those focal lengths, and the 77, M85 f/2, the Sigma 70 and another were sharper, but the Tamron beat all my Taks and other zooms.

I don't live in a world where an in-spec 77 is not 'good enough' for high-MP FF

It's going to resolve more and better than it ever has before, outside of maybe on the K3. Pixel peeping 36MP is going to show you things you never saw before, but you don't print or display 100% crops of test charts. The 77 (and 43, and 31) are great FF lenses even at 36MP, as long as they're not faulty and your AF is on-target.


.
05-06-2016, 03:57 PM - 1 Like   #22
Site Supporter
Fastback67's Avatar

Join Date: Aug 2012
Location: Connecticut, USA
Photos: Gallery
Posts: 278
Maybe it's just me, but in these magnified images from the review, I see the Pentax as the clear winner here?
Attached Images
 
05-06-2016, 04:11 PM   #23
Loyal Site Supporter




Join Date: Apr 2010
Location: Tennessee
Posts: 5,799
QuoteOriginally posted by Pål Jensen Quote
There's nothing wrong with the 77 Limited. It is one of best lenses money can buy....
Not for resolution testing on a FF body. Its a great portrait lens. They would have gotten better results with the $400 D-FA 100mm Macro.

05-06-2016, 04:41 PM   #24
Loyal Site Supporter
clackers's Avatar

Join Date: Jul 2013
Location: Melbourne
Photos: Albums
Posts: 9,022
QuoteOriginally posted by Winder Quote
Not for resolution testing on a FF body. Its a great portrait lens. They would have gotten better results with the $400 D-FA 100mm Macro.
Agreed. It's not a character lens. It's suited to this kind of exercise.

The cross-platform Sigma 70 would have been obvious, as Steve pointed out, to control variables.

I know the journo joined Pentaxforums, but this sloppiness is right up there with when they did their K-1 preview with ... wait for it ... the 50 f2.

Very DPR, very superficial, I'm afraid.
05-06-2016, 06:39 PM   #25
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 27,452
QuoteOriginally posted by Winder Quote
Not for resolution testing on a FF body. Its a great portrait lens. They would have gotten better results with the $400 D-FA 100mm Macro.
People keep repeating this as if the FA 77/1.8 is some sort of soft-focus or portrait-specific design. I was alive back-in-the-day and don't remember the lens being marketed as such when it first came out. Yes, it is a nice focal length for portraits, but it is also nice for still life, floral, close-in action, and pretty much any subject where a moderately narrower FOV from "normal" is desirable and high quality is not a bad thin. I don't have a K-1, but my experience both on the K-3 and on 35mm film is that the FA 77 is no more "portrait designed" than any of my fast 50 Planar-derived "normal" lenses. It is sharp, has good contrast, and a minimum of objectionable characteristics.

I reviewed the results at DPReview and the performance of their test lens is below that which I have come to expect from my copy. Significant image degradation begins just a few degrees off axis and is severe by half-way to the corners (well within the APS-C crop frame).

For sure, something like the Sigma 70mm EX DG Macro (excellent lens...wish I had one) would have been a much better choice, but the FA 77 should have been adequate to the task.


Steve
05-06-2016, 07:01 PM   #26
Loyal Site Supporter




Join Date: Apr 2010
Location: Tennessee
Posts: 5,799
QuoteOriginally posted by stevebrot Quote
People keep repeating this as if the FA 77/1.8 is some sort of soft-focus or portrait-specific design. I was alive back-in-the-day and don't remember the lens being marketed as such when it first came out. Yes, it is a nice focal length for portraits, but it is also nice for still life, floral, close-in action, and pretty much any subject where a moderately narrower FOV from "normal" is desirable and high quality is not a bad thin. I don't have a K-1, but my experience both on the K-3 and on 35mm film is that the FA 77 is no more "portrait designed" than any of my fast 50 Planar-derived "normal" lenses. It is sharp, has good contrast, and a minimum of objectionable characteristics.

I reviewed the results at DPReview and the performance of their test lens is below that which I have come to expect from my copy. Significant image degradation begins just a few degrees off axis and is severe by half-way to the corners (well within the APS-C crop frame).

For sure, something like the Sigma 70mm EX DG Macro (excellent lens...wish I had one) would have been a much better choice, but the FA 77 should have been adequate to the task.


Steve
The edge softness is the problem with a resolution test like this. The 77mm is very sharp in the center like all good portrait lens, but the edges on a FF are not really good enough to take advantage of the resolution of pixel shift. 35mm film doesn't have anything close to the resolving power of a 39MP sensor using pixel shift. The 77mm lens is a great lens, but not for a pure edge to edge resolution test.
05-06-2016, 08:47 PM   #27
Site Supporter
stevebrot's Avatar

Join Date: Mar 2007
Location: Vancouver (USA)
Photos: Gallery | Albums
Posts: 27,452
QuoteOriginally posted by Winder Quote
The edge softness is the problem with a resolution test like this. The 77mm is very sharp in the center like all good portrait lens, but the edges on a FF are not really good enough to take advantage of the resolution of pixel shift. 35mm film doesn't have anything close to the resolving power of a 39MP sensor using pixel shift. The 77mm lens is a great lens, but not for a pure edge to edge resolution test.
Ummmm...the K-1 has a 36Mpx sensor (not 39Mpx*) with pixel density somewhat less than the K-5. As for resolving power of 35mm film, the better B&W emulsions are capable of 300+ lp/mm and I regularly shoot emulsions capable of 100 lp/mm. Per mm^2 of frame real estate, either one of those should be competitive to the native resolution of the K-1 sensor.**

Two questions:
  • What is your source of information regarding the performance characteristics of the FA 77/1.8?
  • What is your experience with film photography that you are able to make claims regarding adequacy of lens sharpness on that medium?
To be fair, I don't want to come across as some sort of FA 77 apologist, except to say that its performance should have been quite adequate for the DPReview test. I also don't want to sound snooty. I just want to know if your claims are based on experience or are your opinions based on what others have written.

FWIW, PF did quick evaluations of several Pentax FF lenses on the Sony A7. While the pixel resolution of that camera is somewhat less than the K-1, the PF staff did not encounter significant edge or corner softness when shooting the FA 77 on that camera. The results including full resolution corner and center crops are at:

Sony A7 with Pentax Full-frame Glass Review - Performance / Handling of Pentax K-mount Lenses | PentaxForums.com Reviews


Steve

* That would be some other camera. Even with pixel shift, the pixel resolution is still 36 Megapixels.
** It takes two pixels to resolve a line-pair so the two systems are definitely in the same ballpark. The problem with film resolution is actually demonstrating it. For lens testing, this is done by direct examination of the negative using a microscope. That is how Zeiss derives its MTF data for its better lenses; they use 35mm film. For pictoral photography, traditional darkroom printing is better than a digital scan, unless you have access to a Flextight (8000 dpi) or a true drum scanner.
05-07-2016, 05:46 AM   #28
Pentaxian
Pål Jensen's Avatar

Join Date: Dec 2007
Location: Norway
Photos: Albums
Posts: 3,148
QuoteOriginally posted by Winder Quote
The edge softness is the problem with a resolution test like this. The 77mm is very sharp in the center like all good portrait lens, but the edges on a FF are not really good enough to take advantage of the resolution of pixel shift. 35mm film doesn't have anything close to the resolving power of a 39MP sensor using pixel shift. The 77mm lens is a great lens, but not for a pure edge to edge resolution test.
You must have bad sample. The 77 was not designed as a portrait lens like the FA* 85/1.4. It has FREE rear elements to ensure sharpness regardless of focusing distance. It is razor sharp.
05-07-2016, 05:55 AM   #29
Loyal Site Supporter




Join Date: Apr 2010
Location: Tennessee
Posts: 5,799
QuoteOriginally posted by Pål Jensen Quote
You must have bad sample. The 77 was not designed as a portrait lens like the FA* 85/1.4. It has FREE rear elements to ensure sharpness regardless of focusing distance. It is razor sharp.
focusing distance has nothing to do with edge to edge resolution.
05-07-2016, 05:56 AM   #30
Pentaxian
Pål Jensen's Avatar

Join Date: Dec 2007
Location: Norway
Photos: Albums
Posts: 3,148
QuoteOriginally posted by Winder Quote
focusing distance has nothing to do with edge to edge resolution.
..but it has something to do with whether a lens are optimized for portraits or not. Mine is sharp corned to corner.
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!
24x36mm, 90mm, full-frame, images, pentax, pixel, pixel shift results, results, shift
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
K1 Pixel Shift tjstimbo Pentax K-1 6 05-06-2016 10:11 AM
Landscape Pixel Shift devem Photo Critique 7 04-09-2016 01:22 AM
Pixel Shift Questions jatrax Photographic Technique 7 03-02-2016 08:38 AM
Pixel Shift Question Wheatfield Pentax Full Frame 5 02-23-2016 11:04 PM
Pixel Shift brophyart Troubleshooting and Beginner Help 6 10-31-2015 02:53 PM



All times are GMT -7. The time now is 01:33 PM. | 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