DA 35mm f/2.8 review at Photozone...

If indeed the lens was within spec, then compared to the testing of the FA35, the edge performance of the DA35 was not as good. On the other parameters the DA seemed to be as good if not slightly better. Perhaps this accounts for the 3.5 stars for the DA 35 versus the 4.0 for the FA 35.

I have asked klaus in his forum to provide the rationale for the number of stars. I assume that there is some reference for a particular type of lens for the various tested parameters and the deviation from the benchmark results in a score. However, he never answered this question.

--
Best regards
Nick

Sure. However, it does not just rely on the sensor though. AA-filter. RAW processing.

Hi Klaus,

Nice work indeed (this statement is biased - I am an addict to photozone.de). How do you choose which lenses to test?
I am quite keen on the 55-300 review - see if my own observations are correct.

On the 35mm I am with you regarding the bokeh - I would have expected more convincing sharpness though, but that's probably because the qualitative observer is centre biased.

cheers
georg

The lenses are either offered to me for testing or purchased in shops.

Klaus,

Thank for performing your exacting lens tests. They must often be tedious and time consuming. And perhaps unappreciated, at least to some extent.

I detect a bit of acrimony in some of the responses here and hope my previous post did not contribute to same. I only stated the obvious, that lens selection is based on more than pure technical qualities.

That said, however, there is no better place to start than with consistent and expert testing by someone that tells it like it is. The Photozone reviews are the first place I go to check on a lens. And I think the photo community owes you a deep debt of gratitude for your work.

Bruce
--
BAB

chris gunn said:

chris gunn said:

Would it be save to
guesstimate that, looking at resolution and vignetting, the lens
would not cover 24x36 adequately?

Click to expand...

I've read here it appears to be fine for 35mm. Surprised me!

Click to expand...

Hi Chris, that would be pretty cool. Do you remember if that was concluded from a slide/negative, or a print (cropped a bit) or a viewfinder impression (might have been cropped a lot, depending on film camera used)?

Cheers
Jens

--

'Well, 'Zooming with your feet' is usually a stupid thing as zoom rings are designed for hands.' (Me, 2006)
My Homepage: http://www.JensRoesner.de

What I criticise the test for, what I criticise any MTF-only test for, is that MTF tests does not tell the whole story of a lens. It is like comparing loudspeakers from test charts without listening to them.

The values of a lens that I talk about, that I care about, is not measured by MTF tests.
It has nothing to with how many lenses Klaus has or has not tested.
It has nothing to with if Klaus is unbiased or not or if I am unbiased or not.

It is a simple matter of the parameters that I talk about cannot be found in MTF tests.

Nothing in Klaus test is about colour rendition, nothing is about colour temperature, nothing is about the saturation and depth-of-colours or lack of depth in colours.
That is why MTF tests doesn't give all the answers.

As I said, I have the DA 35. And I do see a difference.
Even when compared to other SMC lenses.
This is because the DA 35 has the latest version of this coating.
Yes, a newer coating than other Pentax lenses in the current lineup.

In dull weather, this difference between the SMC coatings is not as clearly seen as in good weather with bright sunlight.

If you believe that MTF tests tells everything, then fine.
But I am not a believer in MTF tests, I have never been and I will never be.
Because MTF tests does not tell anything about the character of the lens.
And the chracter is what has made me going for Pentax in the first place.
It is this character that gives images a sense of emotion and soul.

You can't find this in MTF tests, and no, not even in Klaus MTF tests. It has nothing to with his MTF tests being bad or good.
--
Take care
R
http://www.flickr.com/photos/raphaelmabo

Sean Nelson said:

GossCTP said:

I see people talk about the creamy bokeh of a cheap long telezoom at
f/5.6. No, the background is just totally out of focus.

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Well, it's certainly true that the background is out of focus, but
that area can still look good or bad. You don't have to look
farther than the OOF areas from a mirror telephoto to see that:

Click to expand...

All the mirror lenses I've seen are f/8 for one, which gives more DOF. The extreme nature of their bokeh probably takes a lot more defocus to hide as well.

--

Through the window in the wall
Come streaming in on sunlight wings
A million bright ambassadors of morning

All lenses has sample variation.

The numbers is only valid for the tested sample. Users can have samples that are better or worse than that. This is worth keeping in mind.
--
Take care
R
http://www.flickr.com/photos/raphaelmabo

My experience too is that CA is really hard to get with this lens in real-world-situations.
--
Take care
R
http://www.flickr.com/photos/raphaelmabo

Also check out this review ... umm, or let's say user report, at photo.net:

http://photo.net/columns/mjohnston/pentax-35mm-lens/optical-discussion/

Regards,
Olaf
--
Olaf Ulrich, Germany

The tests that Klaus performance measures sharpness, contrast, vignetting and distorsion. And also CA.

But he is not testing the colours - colour temperature, saturation, rendering or nuances of colours. Actually, this is quite hard to test with a machine. You need the eye of a photographer. But the famous Mike does test those parameters, he comments on them, and he compares those parameters with other lenses.

That is why Klaus and Mike writes so different about lenses, because they have different perspective on what is important in a lens performance.
--
Take care
R
http://www.flickr.com/photos/raphaelmabo

Sean Nelson said:

GossCTP said:

I see people talk about the creamy bokeh of a cheap long telezoom at
f/5.6. No, the background is just totally out of focus.

Click to expand...

Well, it's certainly true that the background is out of focus, but
that area can still look good or bad. You don't have to look
farther than the OOF areas from a mirror telephoto to see that:

Click to expand...

That is truly a disgusting image...!!! I really mean that.

Klaus Schroiff said:

The tested sample was not decentered.
Or to be precise - all lenses are decentered. The tested sample was
well within factory specifications and not defective.

Click to expand...

Thank you Klaus for clearing that up. I agree all are decentered to some degree, I was just concerned that as you had mentioned de-centering, it could have been a possible source for concern.

It's very possible that the DA*55 and DA*30 will have a smoother bokeh transistion, as they have been designed to be the APS equals to the much loved FA*85 f1.4 and FA 50 f1.4.

I was hoping that the DA 35 macro would be as "special" as my FA 50 macro, which (as well as the optically identical F 50 macro) has been highly regarded by many for years as one of Pentax's very best resolving lenses with excellent bokeh contrast and colour, plus also doubling as a superb standard lens apart from ultimate speed and shallow DOF.

I shall shortly be trialling a DA35 myself, to do a comparison against my FA 50 macro, purely for my own satisfaction.

As always, everyone has their own reasons for choosing a particular lens, and naturally Pentax enthusiasts would love all Pentax lenses to be perfection, LOL! ;-)
--
Richard Day - 'Carpe Diem!'
Gloucester UK

Bruce
I totally agree with you. I bought the DA35mm Ltd because

a) I'd read so many vary positive statements here

b) I had the chance to test it on my K10D in the shop where they had the 31mm and the 40mmLtd so I could compare them. The 'result' was that although a very very special feel about the 31mm, the 35mm gave a much better 'feel' to the images than the 40mm and I went for it, although the 40mm was better value (the 40mm has a higher score in photozone).

Although the review came out after I bought it I probably still wouldn't have changed my mind - it's the best lens I ever owned and it reminds me of my photographic beginnings with the 6x6 Rolleiflex.

BUT:

How do you convey objective measurements about such rather visceral qualities ??? Especially when you consider that the sensor is digital not film. I guess the only way is a either the costly trial and error principle or picking up the vibes from places like here.

cheers
Georg

jackbw said:

But recently I've started to pay attention to subjective comments
about a lens, trying to understand what "rendering" means. There
must be something beyond what a 2-dimensional chart can show. Too
many experienced users & photographers are talking about it for me
not to pay attention.

Click to expand...

• Yes, there are lots of things... Uncontrollable light sources, the "air", the reflexes, colors, contrasts, darks and lights, hues, saturation, textures, optical illusions, "the mood" (or "the mojo" :-D ), and the list goes on ...

• or just one thing: Art

Look like obvious, but there are measurable and non-measurable things (at least easily). Reviews like these are good and valid for measurable things - and obviously again - there are no possible reviews for non-measurable things... because there are no measure for it.

Regards

Salviano Jr
Rio de Janeiro.

euston said:

The thing that really puzzled me about this review was the comment
that lateral chromatic aberration was "on the high side". I have
found this lens to be markedly resistant to CA. I have even gone out
of my way to induce it with very little success.

Perhaps the quality control department did an especially good job on
my copy of the lens.

Click to expand...

My copy shows CA in any shots with moderate to high contrast edges out towards the edge of the frame. However, it seems to be very consistent and an ACR setting of -10 on the red/green slider wipes it out. Blue/yellow is slightly less consistent but I leave that slider at -10 too without any obvious problems.

--
Gerry


First camera 1953, first Pentax 1983, first DSLR 2006
http://www.pbase.com/gerrywinterbourne

One thing that seemed to have prevented our beloved 35mm from a 4tar rating is its 'nervous' boke. I am doing a lot of fluorescent microscopy and what's done here to gauge optical performance of a lens is to record the point spread functions which essentially means to image very small luminescent objects (like tiny fluorescent beads) in a series of in-focus and out of focus images. You can then project this so called Z-series and see what the optical system does to a point. These patterns are be very informative on overall lens performance and translated to photography could reflect both bokeh and resolution lateral and longitudinal CA in one.

Is anyone out there experimenting with PSF of camera lenses? It should be rather simple: Put a point light source: a standard pinhole positioned far enough to be sub-resolution (maybe tricky for tele-lenses, but otherwise feasible) image in focus and then move gradually out of focus. Project the point images (using some freeware). Quantification could be obtained by using measures such as lateral and longitudinal point distortion (i.e. spread) and its chromatic differences.

Thanks for the good work. I really like it.

however, I guess I'd better list my DA*16-50 on ebay before you review the lens, and if I knew the website earlier I'd been a canon fan instead of being hooked up by pentax

btw, I noticed that the DA70/2.4 got a better review on Optical Quality than FA77/1.8, which is faster , sharper and having less CA but has a purple fringe problem. Does it mean that the standard for a "good lens" is there's no significant technical weakness?

thanks!

--
k10d+bg2 af540 af360
35/2 50/1.4 77/1.8 DA*16-50 DA*50-135 DA*200
sigma10-20 24/2.8II tamron28-75a09 sigma70-300apo

Well, the DA 16-50mm will not be much better than the Tokina 16-50 reviewed in the Nikon scope. There's a slight chance because the Tokina was not a stellar copy but based on what I've seen so far it (the Pentax) seems to be rather soft at f/2.8 (great at f/5.6+).