DA*16-50 Comments


MattMatic

Link Posted 25/06/2011 - 22:56
Thought I'd put up my initial comments on the DA*16-50. It seems to have received a lot of 'bad press', well, 'bad Internet' (which isn't difficult for any subject or object )

Build quality is exactly what you'd expect from the DA* series - superb. It's has a lovely balance and feel, with nicely damped focus ring that allows manual focus (even though the focus throw is merely about 1/4 turn).

Optically - first impression is stunning!

To test, I used Live view and focussed at f/2.8 and the result was superb! But (big but), using normal focus it was massively out. Actually, to be more precise, my K-5 was out and so was the lens. So, I tweaked about (with some other techniques that I may document sometime!) and got the DA*16-50 focussing correctly Had I not gone through that process I would be hugely disappointed

Second optical observation is that under some situations it's a purple fringing monster in JPG! I was shooting JPG for snapshots of the family...
...but all the DNG files were stonkingly good. Lightroom 3 with the profiles does an excellent job of removing the CA, distortion, and any vignetting.

So, I've learned a couple of good lessons - test the focus of a new bit of kit, and use RAW always


There definitely is "something" about the rendering of this lens. The bokeh was infinitely better than I'd read about on the Internet (another lesson reaffirmed ), and because it focusses closer than the 50/1.4 I may find I'm using this beast more and more for shallow DoF. Even at 16mm f/2.8 the DoF is very shallow! Perhaps it's some kind of emotional response (like handling a Limited 31mm ), but there's something magical about it...


...will keep you posted with some real shots soon (have a very exciting commission request coming up that will see this lens getting some serious use! )

For now here's a sample shot processed in LR3 (taken in JPG through a window).

Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)
Last Edited by MattMatic on 25/06/2011 - 22:58

gflauti

Link Posted 26/06/2011 - 16:08
I have an FA 50 1.4 that I use for portraits (usually at F2.8 ).
Could the 16-50 replace FA50 for portraits?
Last Edited by gflauti on 26/06/2011 - 16:09

Anvh

Link Posted 26/06/2011 - 20:48
For portraits you probably can because you don't need the sharpness of a prime lens but the DA*50-135 is i believe a much nicer lens for portraits but that's me. =]
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ

Tyr

Link Posted 26/06/2011 - 22:45
I love my 16-50, a fantastic lens. Sharp, Weather-proof, good focal range, fast, quiet. The lens lives on my camera.

Close focus is great for shallow DoF especially at 50mm.

Even better paired with the 50-135. between them they really do almost everything I could ever want. For longer stuff I have the 300. Sometimes wish for something wider such as an 11-16 also based on a Tokina.
Regards,
Dan

https://www.flickr.com/photos/honourabletyr/
Last Edited by Tyr on 26/06/2011 - 22:46

LennyBloke

Link Posted 27/06/2011 - 08:55
I'm a Prime lens fan through and through, and when I have the time to make a considered choice for the "shoot" I am about to do I will virtually always choose a Prime - But on the many ocassions that I don't know what to expect and I don't want to be weighed down with several pounds of Pentax glass to make my choice from, then the DA* 16-50 is a no-brainer. The range is excellent, the quality ( even at f2.8 ) is superb and the weather-sealing a real bonus.


LennyBloke

MattMatic

Link Posted 27/06/2011 - 09:45
Quote:
Even better paired with the 50-135

Oh, most definitely! Absolute killer combination and both weather sealed too!

It's interesting about comparing the DA17-70 with the DA*16-50... I'm not 100% sure about the differences - perhaps it's the extra stop of light through the viewfinder, or the damped focus ring, or the extra construction. The DA17-70 is still an utterly brilliant lens (with incredible sharpness, contrast, and lovely bokeh). Hopefully I can do some more scientific "real world" tests later

Only minor niggle is that my camera bag arrangements need revising since the DA*16-50 is a bigger beast, especially with the hood on. The DA17-70 certainly scores for compactness

EDIT: The DA*16-50 seems to focus faster overall. The DA17-70 can move the focus ring quicker, but often overshoots and has to hunt. The 16-50 hardly hunts at all Quick comparison shows very little difference in rendering at f/4, but the 16-50 is subtly smoother (the 17-70 seems to catch shadows more readily in the OOF area showing them as darker areas. But it's slight). The extra 1mm is surprisingly significant, and I'm missing the extra 20mm less than I'd feared.

I'm still cautious over the purple fringing on the 16-50 - I have a couple of shots that will definitely need PP. Noteworthy is the fact the shots were JPG - and I haven't yet recreated it in RAW (but absence of evidence is not evidence of absence!) It's not your usual CA, but a definite 'bloom' of purple - looks like when the out-of-focus area catches a high contrast area in bright light (maybe UV related?). Not disastrous by any means, but something I'd like to pin down a bit more

Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)
Last Edited by MattMatic on 27/06/2011 - 11:16

Pentaxophile

Link Posted 27/06/2011 - 15:22
The difference between 16 and 17mm is surprising isn't it? I noticed that going from my 16-45 to my 17-50mm.
[link=https://500px.com/will_brealey/[/link]

MattMatic

Link Posted 28/06/2011 - 21:58
Here's another little snapshot - shot wide open, f/2.8, 43mm, ISO640, 1/80s. Fractionally back-focused as the cat wasn't too happy with me taking its mug-shot!
http://www.mattmatic.co.uk
(For gallery, tips and links)

Anvh

Link Posted 28/06/2011 - 22:05
This lens is also very nice for filming because it manual focus quite easily, it's my standard film lens.
Stefan


K10D, K5
DA* 16-50, DA* 50-135, D-FA 100 Macro, DA 40 Ltd, DA 18-55
AF-540FGZ
Last Edited by Anvh on 28/06/2011 - 22:06

MattMatic

Link Posted 30/01/2012 - 13:45
Now I have had this lens for some time, I'm just adding some comments...

Quote:
Second optical observation is that under some situations it's a purple fringing monster in JPG!

Further investigation shows that it's actually Longitudinal Chromatic Aberration (LCA or LoCA) when wider than f/4, also known as "Bokeh Fringing". It occurs at points of highlight - for example white whiskers on a black cat (which is what prompted me to investigate further).

I thought I'd try a UV filter to see if it made any difference... nope!

However, what I did notice was that out of focus items in front of the focus point give a blue highlight, while highlights to the rear show yellow fringing. Once you get to f/4 it's not noticeable.

I tested by placing white cord on to a black camera bag in sunlight and checking at 100% view. Taking a shot at 45 degrees will show the blue/yellow split.

HTH!
http://www.mattmatic.co.uk
(For gallery, tips and links)
Last Edited by MattMatic on 30/01/2012 - 13:46

stevejcoe

Link Posted 30/01/2012 - 14:45
Quote:
To test, I used Live view and focussed at f/2.8 and the result was superb! But (big but), using normal focus it was massively out. Actually, to be more precise, my K-5 was out and so was the lens. So, I tweaked about (with some other techniques that I may document sometime!) and got the DA*16-50 focussing correctly Had I not gone through that process I would be hugely disappointed

Hi Matt, any chance of elaborating on this?

Regards - Steve

MattMatic

Link Posted 30/01/2012 - 15:22
Steve - the forgettory has forgotten

I think I was experimenting with focus adjustment methods. The standard method is to use a focus assist chart at 45 degrees (horizontally preferably as shown by Pentax's service manual, which keeps the camera level).

I was probably making use of the pixels of an iMac LCD display (probably displaying the focus chart on there) and viewing zoomed in on the camera. Someone once said that the moire pattern could be used, but I had limited success with that because of resampling on display of the image on the LCD.

Don't forget that the LiveView focus should be 100% as it's taken off the sensor directly, whilst the phase shift AF is done with the mirror down (and it's this that the micro adjustment works on).

Now you've reminded me, I might revisit the idea...
Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)

stevejcoe

Link Posted 30/01/2012 - 18:32
Thanks Matt, after quite a lot of practice, I do now get reasonably consistent test results. I find the hardest part of the process is setting the camera/lens at 45 degrees to the test chart.

Regards Steve

vrapan

Link Posted 30/01/2012 - 20:48
Mine should be arriving tomorrow, will have to have a go at it so far 2 out of 6 of my lenses including my 40mm and the 18-55 WR are off by a little bit. The 50-135 is spot on as are the rest of my pancakes and the 10-20 (although i find it generally a tiny bit soft).

If colours and contrast are anything like the 50-135 I don't think I will care much about focus being a bit off or curving straight lines.

MattMatic

Link Posted 30/01/2012 - 21:24
It's an excellent match to the DA*50-135
LR3 has the correction parameters for it so it does look great when using raw. It's just the blue/yellow LCA that causes a bit of a problem sometimes, but it is such a lovely piece of glass. Bokeh, colour and contrast are loverly!!

BTW most of my lenses needed a bit of focus adjustment.

Re: 45 degrees - you don't need to be accurate with it! It's just so you get a good spread of focus and a way of comparing when adjusting.
Matt
http://www.mattmatic.co.uk
(For gallery, tips and links)
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