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Old Apr 18, 2007, 6:44 PM   #1
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WTF is this? Out of a limited lens? Awful!

http://www.flickr.com/photo_zoom.gne...391&size=l



I am very much aware the highlights are so completely blown you can't even call em highlights anymore...... but this is a super sunny day, so it's NORMAL. The purple fringing is AWFUL!

Is this typical of the DA40?
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Old Apr 19, 2007, 8:37 AM   #2
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Gazander wrote:
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WTF is this? Out of a limited lens? Awful!

I am very much aware the highlights are so completely blown you can't even call em highlights anymore...... but this is a super sunny day, so it's NORMAL. The purple fringing is AWFUL!

Is this typical of the DA40?
Either it is off focus or back focusing too. Not to mention that the lighting is atrocious. Any possibility that you can shoot with another lens of the same scene?

Daniel , Toronto
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Old Apr 19, 2007, 3:11 PM   #3
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unfortunately not, this isn't my shot.

If you check the large pic, 3000x2000, you can see how awful it really is:

http://www.flickr.com/photo_zoom.gne...391&size=o
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Old Apr 19, 2007, 5:19 PM   #4
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Gazander wrote:
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unfortunately not, this isn't my shot.

If you check the large pic, 3000x2000, you can see how awful it really is:

http://www.flickr.com/photo_zoom.gne...4269391&size=o
That is a wide open shot at F2.8 iso 800 1/4000s Av priority. Definitely misfocusing or backfocusing. One big surprise: when it is in focus it is quite sharp wide open (see left shop sign) There could be a flare issue as well given the overexposure. Overall a very awkward example.

Daniel , Toronto
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Old Apr 20, 2007, 11:23 AM   #5
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I don't see what focus has to do with it. You can see CA through the entire distance

tree branches, the guy's banner, the red car, the motorcycle wheels, etc.

Whenever asked, people just say "it's tiny" and rarely speak of the optical performance.

I'm busting chops because for reasons I don't understand, I am interested in buying this lens, but I want good performance for the money.

Daniel what have you heard about this lens? You seem to know a lot about it.
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Old Apr 20, 2007, 4:43 PM   #6
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I got the lens in yesterday and did a few test shot at home. I am amazed and the quality and how "punchy" the image is. The colors are very saturated and bright. When I did the test shot, I did it in jpeg at defualt setting on all. I didn't reall do a side by side comparson with my FA 50mm f/1.4, but I just notice the color were more saturated.

I highly recommond this lens for anyone looking for a standard prime lens. For the money, you can't get any better than this. The rebate makes it even a better deal. Gazander, I am not sure if you qualify for the US rebate, but if you do, I won't pass on this deal. Also if for any reason you don't like it, you can always sell it on ebay for the same amount that you paid for, maybe even more.

As far as the picture goes, I think that is just a rare shot where it just happens to be like that. I wouldn't let one shot stop you from buying such a great lens.

Before I bought this, I did a lot of research on it. Everyone that I found, seems to love the lens. None of the shots that I saw with that lens had the problem with CA. I just wish this lens was faster but f/2.8 is okae with me.

Here are some shots on pbase.com that I think you should look at.
http://www.pbase.com/cameras/pentax/..._40_28_limited
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Old Apr 20, 2007, 6:24 PM   #7
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Gazander wrote:
Quote:
I don't see what focus has to do with it. You can see CA through the entire distance

tree branches, the guy's banner, the red car, the motorcycle wheels, etc.

Whenever asked, people just say "it's tiny" and rarely speak of the optical performance.

I'm busting chops because for reasons I don't understand, I am interested in buying this lens, but I want good performance for the money.

Daniel what have you heard about this lens? You seem to know a lot about it.
I have no personal knowledge of it. Yet.

http://www.stevesforums.com/forums/v...55&forum_id=94

I should expect to receiving it in a month's time hopefully. Placed an order with Henry of Toronto earlier.
There are quite a few positive input from other new owners with rave report. Somehow the search of dpreview does not work. But before that my search came back all with rave report of this lens.

Daniel, Toronto
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Old Apr 20, 2007, 9:52 PM   #8
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Well, I am no expert, however I think that for the particular situation, this may be a pretty good shot - maybe not for the obvious reasons.

The image indicates that it was taken at F2.8 iso 800 1/4000s Av priority. For wide open at f2.8, take a look at the trees along the left hand side and the signs between the trees. The depth of field in great. The trees must be 30 feet appart - the one in the foreground is in focus, while the next one in line is also in focus. The signs on the right hand side of the image are in focus also, across a wide range of distances.

The shot is into direct sunlight - check the shadow of the banner, and is filtered through the tree. Now the leaves directly filtering the light have the CA - along with a section of leaves in the next tree. I would think that anything between the sun and the camera is going to have this effect is such a strong sunlight - I may be wrong - but you can get this effect in astronomy.

Also if the street surface is concrete - and is relatively white (light grey), then you have a lot of light surfaces (along with the grey sky) washing out everything, essentially making the entire image particularly difficult to capture - at f2.8. There is only some grain present (they guy in the car on the left hand side) - which at 800 again is pretty good.

For such a strong light - and with the smog/overcast in the background - I think that overall the environment is pretty harsh - with the lens wide open - I think that this is not all that bad - actually pretty good considering the conditions. Considering the shading - the bright reflective surfaces, the direct sunlight, the fast speed and the wide open lens - you are pushing the limits all around the envelope.

But then again - I have a set of coke bottle lenses resting on my nose.....
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Old Apr 26, 2007, 4:25 PM   #9
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This fellow has summerised Photozone's input mainly on MTF on DA40mm Limited. Do not read too much into this as great lens is more than just paper sharpness


========================================
A lot of people have commented: "Confirms my experience"

And it does.

However, if you asked me what to guess the sharpest lens was at

various apertures, I would have been often wrong. And this is useful info to know!
The following from Photzaone center sharpness MTF.

F2.8.

Usefull aperture for portraits. Many people have said the 43 is soft utill around f4.5. The unexpected result:
43 > 50 > 40.

F4.

It's nice to use THE sharpest aperture at times. I had thought this would be at f8-F9.5. silly me. The 50 had an impressive figure of 2320. Almost 99% of the supposed max. totally wupped by the 43:
43 > 50 > [email protected] > [email protected] > 40 > [email protected] [f3.5]

F5.6.

Most lenses are expected to be good by F5.6, so it's a popular aperture. If you asked anyone jow the 50 would compare to others at f5.6, they would say it would be right up there.
Where does it come? Gasp!
43 > [email protected] > [email protected] > 40 > 50 > [email protected] > [email protected]

F8.
Often used for best sharpness with big DOF. I use F8 a lot.
Landscape. Groups. etc. Who's #1? Is the 40 an unimpressive lens optically?
40 > [email protected] > [email protected] > [email protected] > 43 > [email protected] > 50 > [email protected]


Freakish! To be fair however, the figures are all close at f8. From best to worst is about 7% of the sharpness range.
How will this change my shooting habits?
Well... I might use the 43 at F4 more often 9-). And F2.8.
I might feel better about using the 16-45 at F5.6.
At F8, both zooms are prime are good.

Of course center sharpness is only one part of the complex IQ question.


The last time I tried comparing the 43 and 50 at f2.8, I couldn't say which was sharper, and the figures are 2311 and 2089 which is like 28% more than the difference beween the sharpness range at f8.

cheers!

Chris Gunn
===============================================
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