Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
11 Likes  
DA lenses on Full Frame: Test Shots thread
Posted By: falconeye, 07-07-2008, 02:50 PM

Hi everybody,

I would like to open up a thread dedicated to one topic:

DA lens on Full Frame: a sticky test shots thread.

This thread shall be dedicated to test shots of a DA lens mounted to a full frame body (e.g., a film camera body). By test shot, I mean shots dedicated to evaluate the performance. Shots of ordinary subjects aren't suitable to this task, normally, and should not be posted. So, these are the rules:
  • K mount lens dedicated to the APS-C form factor is used.
  • Image is taken full frame 36mm x 24mm.
  • Lens hood was removed.
  • And ideally, no filter is mounted.
  • The aperture used is specified (note that film cameras don't record EXIF...).
  • Sample image shows the entire field of view.
  • Sample image(s) show(s) corner, border and center performance at 10MP-100% (multiple crops, or single not-resized image).
  • The subject is such that resolution and vignetting at the borders can be compared to the center.
The idea behind this thread is obvious: To compile enough data to assess the spectrum of available lenses for a forthcoming full frame DSLR in K mount.

#################################################

Table of results as obtained in this thread (updated regularly):
SMC Pentax-DA primes...
SMC Pentax-DA zooms...
Sigma K mount DC...
  • Sigma 18-200mm f/3.5-6.3 DC: -
  • Sigma 10-20mm f/4-5.6 DC: - (below 14mm, Gooshin)
  • ...
Tamron K mount Di-II...
  • ...
Overall rating scale:
+++: no significant difference between APS-C and FF corners
++: difference but usable at full aperture with a small loss in corner IQ only
+: usable staring at f/4~f/5.6, with no or a small loss in corner IQ only
o: usable at f/11 or with big loss in corner IQ only
-: not usable


Last edited by falconeye; 07-20-2016 at 02:57 AM. Reason: Result table updated
Views: 312,166
12-16-2009, 09:46 AM   #121
New Member




Join Date: Apr 2009
Posts: 6
QuoteOriginally posted by falconeye Quote
Steelski, I do not want to discuss another forum too much. So, let me make the following, short comments:

- You're right, post #177 said f/1.4. I don't remember why I thought it is f/8. But too tiny to evaluate resolution anyway.

- There is a new post #234 - #237 with a resolution test at f/1.4. Unfortunately, those guys don't realize that the ISO 12233 test chart is limited to 2000 LW/PH and even show crops of the chart where it is limited to 1000 LW/PH! So, all we learn is that 1000 LW/PH are resolved. Why I produced my own version of the ISO 12233 test chart to measure up to 3000 LW/PH (limited by my scanner & printer, not the chart). Note that 3000 LW/PH is the K20D sensor's resolution.

- Vignetting from the hood is normally pretty obvious. And not visible from the f/1.4 shots. So, those shots either are w/o hood or the hood doesn't cause vignetting. The angle of the 55mm is almost 43 in the corners. If the hood isn't vignetting then this would mean that it was designed to work on FF too. But we still lack resolution figures. Untill we can give it a +++ rating we don't really know.
I went over these posts on Xitek.com, the post #177 said f8 but it's about something else, not related to the MZ_S DA55* photo in post #178. author of poster 178 did not give information on aperture used, the f1:1.4 under the photo is only a description for lens used.

Post #234 - #237 are taken by digital body, not related to our topic, they are comparing 1650 50135 and 55.

actually #177 is the only post with photo regarding DA55* on film body

12-16-2009, 12:08 PM   #122
Veteran Member
danielchtong's Avatar

Join Date: Jul 2007
Location: Toronto
Posts: 754
QuoteOriginally posted by Adam Quote
DA lenses are not full-frame lenses, barring the 40mm,
Well I know another confirmed exception.
DA*200mm is actually a repackaged FA*200mm except that the former is weather-sealed and SDM equipped.
Both share exactly the the same optics.
I had it confirmed before buying that

Daniel
12-16-2009, 12:10 PM   #123
Veteran Member
danielchtong's Avatar

Join Date: Jul 2007
Location: Toronto
Posts: 754
[DA?200F2.8???] PENTAX DA?200F2.8 ?????? - Pentax Fans Club


Unfortunately it is in Chinese. But the images of this lengthy comparison has confirmed way back that DA* & FA*200mm have the same optics
01-03-2010, 12:46 PM   #124
Senior Member
architorture's Avatar

Join Date: Apr 2008
Location: New York, NY
Posts: 151
RE: DA12-24 on film

So, as I promised I got my hands on some free time and a good scanner and finished things off for my test of the DA 12-24 on film.

I scanned the negatives with an Imacon 949 at 4000dpi. For the sake of posting I then resized down to 3200dpi and made 500x500 crops from the center and extreme corner of each frame. This is about like looking at a 13MP image at 100%. I have applied absolutely zero sharpening in the process (flickr made the jpegs though).

Since 2crops x 2 apertures x 5 focal lengths = 20 images I am providing the link to my set on flickr rather than post so many images in the forum. You can see them all (including the full-frame noritsu scans of each) here.

CONCLUSIONS
If you'd rather not take the time to look, here are my conclusions:

- mechanical vignetting disappears ca. 18mm regardless of aperture

- corners actually look sharper @ 12 than the intermediate focal lengths, but of course to use them you would have to crop the film considerably (to aps-c size)

- @ f/4 corner blurring does not reach "acceptable" levels until 24mm

- @ f/8 corner blurring is "acceptable" at 18mm, pretty much a non-factor at 20mm and 24mm

- I do not see much difference in the center btwn f/4 and f/8 in resolution, but f/8 maybe has more contrast (light could have changed though).

- lastly, I think the mechanically vignetted pictures are kinda cool looking, though you will get people asking if it is a fisheye lens because it looks like a circular fisheye to the un-knowledgeable.

I hope I have not forgotten anything, and that this is helpful to others. I wish I had more DA lenses to try!

02-23-2010, 07:33 AM   #125
Veteran Member
froeschle's Avatar

Join Date: Sep 2007
Location: Germany
Photos: Gallery
Posts: 552
According to this blog the DA 60-250 shows vignetting from about 85 to 250mm (see pictures; google translate indicates: "food [=hood?] was removed", "all open F4"). The lens thus seems not to cover FF.
02-23-2010, 07:40 AM   #126
Veteran Member




Join Date: Oct 2008
Location: Zagreb, Croatia
Posts: 369
QuoteOriginally posted by froeschle Quote
According to this blog the DA 60-250 shows vignetting from about 85 to 250mm (see pictures; google translate indicates: "food [=hood?] was removed", "all open F4"). The lens thus seems not to cover FF.
i had no film in my P5 when i had the opportunity to test the DA*60-250, so no photos were taken, but there were absolutely no signs of even slightest vignetting through the whole range in a viewfinder. if it vignettes, it's only slightly.
02-23-2010, 08:05 AM   #127
Veteran Member
froeschle's Avatar

Join Date: Sep 2007
Location: Germany
Photos: Gallery
Posts: 552
QuoteQuote:
through the whole range in a viewfinder
Even if you were looking through a viewfinder with 100% view of field it could be difficult to see "problems". However, vignetting is obvious in the pictures and - contrary to intuition - increases with increasing focal length.

In addition, there is the question, whether a lens is also properly corrected in the extreme corners. This is e.g. not the case for the DA70 (according to Arnold in the dfn ).
02-23-2010, 11:04 AM   #128
Pentaxian
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,862
Original Poster
QuoteOriginally posted by froeschle Quote
the DA 60-250 shows vignetting from about 85 to 250mm
QuoteOriginally posted by elkarrde Quote
but there were absolutely no signs of even slightest vignetting through the whole range in a viewfinder
+1
I did the same film camera VF test. No visible vignetting.

My resolution test of the 60-250 is still pending.

Meanwhile, I have strong problems with the credibility of the vignetting report above. The vignetting at 250mm should be very strong. But invisible in the VF?

And I made another test too:

you can looking thru the lens (from behind) and you'll see the aperture's exit pupil. Fully open, it is circular. If you turn it slightly left or right, you'll see that the exit pupil becomes obstructed (not perfectly cicular anymore).

I measured the turning angle between left and right obstruction: 11.

A full frame lens corner to corner at 250mm focal length covers 9.9.

As soon as the exit pupil becomes obstructed you'll see the corners darken. As soon as the exit pupil blacks out you'll see black corners (happens at 26). Half way in between, you lost 50% of the exit pupil or 1 EV in the corners. What I see in the posted images is 6 EV vignetting!!. Which should happen at 25 or more than a medium format image circle only! I am not convinced that the posted sample shots are from the 60-250mm. After all, film carries no EXIFs, errors are likely.

Therefore, I'll say for the time being that there is zero vignetting on FF except for the obvious cos^4 term. 11 is so close to 9.9 that I am tempted to say it was designed to cover the FF image circle ...


And my resolution test of the 60-250 is still pending


Last edited by falconeye; 02-23-2010 at 11:26 AM.
04-14-2010, 09:18 AM   #129
Senior Member




Join Date: Dec 2009
Posts: 127
any news on the 60-250?
04-16-2010, 08:44 AM - 1 Like   #130
Pentaxian
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,862
Original Poster
QuoteOriginally posted by vespats Quote
any news on the 60-250?
The item just got bumped 5 positions up on my to do list (still not on top though )
04-29-2010, 01:21 PM   #131
Pentaxian
jsherman999's Avatar

Join Date: Dec 2007
Photos: Gallery
Posts: 8,228
.

Falk, great idea for a thread, very useful.

I can show some examples from the Tokina 12-24 f4 on a FF DSLR (D700) - basically the same thing you'd see with the DA 12-24 on film (same lens, sans coatings, maybe.)


.
12-24 @ 12mm

12-24 @ 15mm

12-24 @ 18mm

12-24 @ 19mm




Incidentally, the $199 Nikon 35 1.8DX - supposedly an APS-C only (DX) lens, works nicely on FF, as long as you're not shooting near infinity:


f/5, ISO 1250:


f/2.8, ISO 2000:


f/2.8, ISO 640:
04-29-2010, 02:28 PM   #132
Pentaxian
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,862
Original Poster
QuoteOriginally posted by jsherman999 Quote
I can show some examples from the Tokina 12-24 f4 on a FF DSLR (D700) - basically the same thing you'd see with the DA 12-24 on film (same lens, sans coatings, maybe.)
jsherman, great idea to make reference to lens versions for bodies which have FF versions available. This could help fill the gaps.

As far as your valuable sample images are concerned: Is this with or without the lens hood? It looks like the vignetting is caused by a lens hood with a rectangular opening.
05-17-2010, 03:42 AM   #133
Pentaxian
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,862
Original Poster
DA*300/4 confirmed FF

Pentax has confirmed the DA*300/4 to be full frame.

The following is the patent filed by Pentax describing the DA*300 lens design: DA* 300

One is learning that the DA*300 is 290mm f/4.1 and Table1 applies a crop factor of 1.00. It isn't the FA*300/4.5 as the patent describes an 8 element in 6 groups lens. The FA*300 has 9 elements, the A*300 has 8 elements but 7 groups. And the original patent is from April 2007, a year before the DA*300 was released.

Table1 gives angle of view and focal length and from that, one can compute the image circle which yields the crop factor. 1.00 is the computed value from the patent. Some other Pentax patents yield 1.52-1.54 when doing the same.

So, we now may officially learn from Pentax that the DA*300/4 is a full frame lens.

I updated the opening post of this thread accordingly.
(I am still giving it an "++" rating because there is slightly better performance in the APS-C corners compared to FF. Probably true for all FF lenses though.)
05-17-2010, 09:56 AM   #134
Pentaxian
falconeye's Avatar

Join Date: Jan 2008
Location: Munich, Alps, Germany
Photos: Gallery
Posts: 6,862
Original Poster
DA*60-250/4 confirmed FF

Pentax has confirmed the DA*60-250/4 to be full frame.

The following is the patent filed by Pentax describing the DA*60-250 lens design: DA* 60-250mm f/4

The patent for the DA* 60-250/4 describes several versions, like
61.5 - 243mm f/4.1 or 56.1 - 243mm f/4.1.

The crop factor in all versions is ~0.98/1.03/1.02 at wide/medium/tele zoom.

And no, 0.98 doesn't mean it vignettes. It is just rounding errors when converting angle of view to crop factor.


So, this is the official confirmation from Pentax that the DA*60-250/4 lens is a full frame lens indeed.


I updated the opening post of this thread accordingly.
(I am giving it a "++" rating which is temporary until it is tested.)
05-18-2010, 04:48 AM   #135
Pentaxian
Class A's Avatar

Join Date: Aug 2008
Location: Wellington, New Zealand
Posts: 8,934
Great detective work, Falk!
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!
60-250mm, aperture, bodies, body, camera, corner, da, da*, da* 60-250mm, f2.8, f4, ff, film, flickr, focus, frame, k-mount, lens, lenses, op, pentax, pentax lens, pm, post, sdm, sensor, shots, slr lens, tests, thread
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
DA Lenses on Full Frame (DA 35 ltd) Painter Pentax Full Frame 18 05-29-2016 04:42 PM
DA lenses on Full Frame hjoseph7 Pentax SLR Lens Discussion 6 12-03-2014 01:14 PM
TEST: smc PENTAX DA 35mm 2.8 Macro Limited on Full Frame vjacesslav Pentax SLR Lens Discussion 2 03-17-2012 06:41 AM
DA lenses on Full Frame: Test Shots falconeye Pentax Lens Articles 0 07-07-2008 02:50 PM
DA lenses on full frame sensor ZigDaPig Pentax DSLR Discussion 16 01-05-2008 11:22 AM



All times are GMT -7. The time now is 07:28 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