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03-01-2017, 06:40 PM   #1
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D-FA HD 28-105 WR first impressions

Bought mine through B&H, it came today with a single piece of big bubble wrap around it in a very large box. So the lens itself had to have been clacking around the shipping box through shipment.

Tried it out. It is a small, light lens. Very similar in size and weight to the DA 18-135mm. My copy needed +2 AF adjustment no prob.

First impression, this lens sucks! And this lens also blows! No, really. When I turn the zoom ring, it sucks and blows air through the microphone port dramatically. If I unplugged the rubber port seal, I could probably clean dust off of lenses just by placing the dusty lenses near the microphone port of the K-1 and turning the 28-105's zoom wheel.

This is an issue with any non-internal focusing lens. It seems dramatic though with this 28-105 than my other lenses. Perhaps that means the weather sealing is decent-ish though. Both of the lens and in the K-1.

The extension parts of the lens also bind slightly in the middle of the zoom range. After watching it carefully, I can see they are slightly tilted upward maybe 1 mm at the most. Most people probably wouldn't have even noticed. It is a kit lens and it shows. But, for a kit lens, the IQ is nice enough. Not prime sharp, but I wasn't really expecting that. Still plenty of resolving power. Only minimal vignetting at 28mm and LR6 clears that away entirely.

And it seems at fastest aperture, there is a faint but visible dividing line in the frame of sharpness... somewhere around 2/3 to 3/4 out from center. That continues all the way to the corners which (the corners) are disappointing to me.

Used in crop mode that wouldn't be an issue as 1.5x crop would contain the entire 'circle' of sharpness.

I plan to take this lens out and test more... it might be going back for a second copy...



Anyone else experience the same things as I have with this lens? Anything else I need to look for while testing?

03-01-2017, 06:51 PM   #2
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I have not had anything but pleasant surprises with this lens. I did not notice the air issue, but I am curious now to listen. Did this cause a problem?
03-01-2017, 06:52 PM   #3
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QuoteOriginally posted by mee Quote
Bought mine through B&H, it came today with a single piece of big bubble wrap around it in a very large box. So the lens itself had to have been clacking around the shipping box through shipment.

Tried it out. It is a small, light lens. Very similar in size and weight to the DA 18-135mm. My copy needed +2 AF adjustment no prob.

First impression, this lens sucks! And this lens also blows! No, really. When I turn the zoom ring, it sucks and blows air through the microphone port dramatically. If I unplugged the rubber port seal, I could probably clean dust off of lenses just by placing the dusty lenses near the microphone port of the K-1 and turning the 28-105's zoom wheel.

This is an issue with any non-internal focusing lens. It seems dramatic though with this 28-105 than my other lenses. Perhaps that means the weather sealing is decent-ish though. Both of the lens and in the K-1.

The extension parts of the lens also bind slightly in the middle of the zoom range. After watching it carefully, I can see they are slightly tilted upward maybe 1 mm at the most. Most people probably wouldn't have even noticed. It is a kit lens and it shows. But, for a kit lens, the IQ is nice enough. Not prime sharp, but I wasn't really expecting that. Still plenty of resolving power. Only minimal vignetting at 28mm and LR6 clears that away entirely.

And it seems at fastest aperture, there is a faint but visible dividing line in the frame of sharpness... somewhere around 2/3 to 3/4 out from center. That continues all the way to the corners which (the corners) are disappointing to me.

Used in crop mode that wouldn't be an issue as 1.5x crop would contain the entire 'circle' of sharpness.

I plan to take this lens out and test more... it might be going back for a second copy...



Anyone else experience the same things as I have with this lens? Anything else I need to look for while testing?
I got mine from B&H two weeks ago. It has no issue. Focusing is accurate and silent. The lens, so far has exceeded all my expectations. The fast focusing, even in low light situations, is worth the cost of the lens alone. I am confused about your problem with air blowing out of the lens. The lens has internal focusing. Only the zoom action extend the barrel which could be a source of air coming out of the lens. Sorry can't help. I have not done any videos so I cannot confirm your findings.

From your description of the problem, sounds like the barrel may be out of alignment or something like that. If it ends up being a bad copy, send it back for a replacement. B&H stands behind their products. I have sent a few items back for replacement and they made good on them.
03-01-2017, 07:09 PM - 1 Like   #4
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QuoteOriginally posted by mee Quote
Bought mine through B&H, it came today with a single piece of big bubble wrap around it in a very large box. So the lens itself had to have been clacking around the shipping box through shipment.

Tried it out. It is a small, light lens. Very similar in size and weight to the DA 18-135mm. My copy needed +2 AF adjustment no prob.

First impression, this lens sucks! And this lens also blows! No, really. When I turn the zoom ring, it sucks and blows air through the microphone port dramatically. If I unplugged the rubber port seal, I could probably clean dust off of lenses just by placing the dusty lenses near the microphone port of the K-1 and turning the 28-105's zoom wheel.

This is an issue with any non-internal focusing lens. It seems dramatic though with this 28-105 than my other lenses. Perhaps that means the weather sealing is decent-ish though. Both of the lens and in the K-1.

The extension parts of the lens also bind slightly in the middle of the zoom range. After watching it carefully, I can see they are slightly tilted upward maybe 1 mm at the most. Most people probably wouldn't have even noticed. It is a kit lens and it shows. But, for a kit lens, the IQ is nice enough. Not prime sharp, but I wasn't really expecting that. Still plenty of resolving power. Only minimal vignetting at 28mm and LR6 clears that away entirely.

And it seems at fastest aperture, there is a faint but visible dividing line in the frame of sharpness... somewhere around 2/3 to 3/4 out from center. That continues all the way to the corners which (the corners) are disappointing to me.

Used in crop mode that wouldn't be an issue as 1.5x crop would contain the entire 'circle' of sharpness.

I plan to take this lens out and test more... it might be going back for a second copy...



Anyone else experience the same things as I have with this lens? Anything else I need to look for while testing?
My first thought was return the lens. After rereading your post, my second and third thoughts are: return the lens.

It sounds like it's badly decentered at least (the diving line of sharpness), and the impingement and visible separation just sound like issues waiting to happen. call B&H and describe the condition of the lens on arrival and the poor resolution. they should give you an rma to send it back.

03-01-2017, 07:23 PM - 1 Like   #5
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Every WR lens does this with the air. That's normal.

But I'd get the lens exchanged, as it sounds like it was somehow damaged in transit.

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03-01-2017, 07:46 PM   #6
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My copy is very sharp, no issues with the build. Enjoying the hell out of it. The peak mtf suppose to be around f8, at that aperture its razor sharp. But it's perfectly fine wide open too, at least for what I expect from it.
03-01-2017, 07:49 PM   #7
mee
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QuoteOriginally posted by btnapa Quote
I got mine from B&H two weeks ago. It has no issue. Focusing is accurate and silent. The lens, so far has exceeded all my expectations. The fast focusing, even in low light situations, is worth the cost of the lens alone. I am confused about your problem with air blowing out of the lens. The lens has internal focusing. Only the zoom action extend the barrel which could be a source of air coming out of the lens. Sorry can't help. I have not done any videos so I cannot confirm your findings.
Well.. I didn't need you to defend the lens. But thanks all the same.

I had heard about the air issue with these types of lenses before on the K-1 (through other users posts here on PF), so I was more tuned to looking for it. It doesn't happen on my K-5II but it does on my K-1. If you have a K-1 go try it! Take the mic port seal off and stick your finger near it then zoom the lens back and forth. I tried with my 18-135 WR and my 16-50 on the K-1 and both do it.

Like I said it isn't a problem with my lens.. it is just how the design works with these sucker/blower type lenses. On my 50-135 it doesn't do this because it doesn't extenderize I think.

QuoteOriginally posted by btnapa Quote
From your description of the problem, sounds like the barrel may be out of alignment or something like that. If it ends up being a bad copy, send it back for a replacement. B&H stands behind their products. I have sent a few items back for replacement and they made good on them.
It might be transit issue... or it might just be a QA issue with this lens. If I put a finger on the top of the lens hood (extremely minimal pressure) and zoom in and out it doesn't have any binding noise (which was minor to being with). I think the tolerance level is so minimal that this stuff just happens with a 500 dollar lens.

As far as decentering perhaps so. I think sloshing around the shipping box surely didn't help it.. Thankfully I record video when I open new shipments so I have proof of the state of packaging should the lens go back (at this point reading the comments it likely will).

I'm not 100% sure it is decentered though.. I'll take more shots soon when there is daylight and see though.
03-01-2017, 09:28 PM   #8
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QuoteOriginally posted by mee Quote
D-FA HD 28-105 WR first impressions
Your impression is that you don't like the lens and you mention a few things that could be the reason.
If you were evaluating a half filled glass of water, either going for describing how half full is the glass or how half empty is the glass, you have chosen to describe the half empty glass.
The lens is well seal, and that's why there is inevitably an air flow. As far as sharpness is concerned , my copy is very sharp on full frame.

03-02-2017, 06:45 AM - 1 Like   #9
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The 18--135 was an air pump on my K3 as well while zooming.
03-02-2017, 06:46 AM   #10
mee
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QuoteOriginally posted by biz-engineer Quote
Your impression is that you don't like the lens and you mention a few things that could be the reason.
If you were evaluating a half filled glass of water, either going for describing how half full is the glass or how half empty is the glass, you have chosen to describe the half empty glass.
The lens is well seal, and that's why there is inevitably an air flow. As far as sharpness is concerned , my copy is very sharp on full frame.
My impression is I do like the lens, but not all about the lens. Most people don't post what they like because they expect to like, otherwise they wouldn't have bought. no?

I was commenting on and reaching out to see of those aspects were normal for this particular lens. It seems they aren't entirely (thank you to all who responded on topic), so the thread accomplished it's goals. My first impressions were honest first impressions.

Everyone's definition of 'sharp' is going to be varied. So your comment would help more with more detail. Either way, I'm glad you are happy with your copy of this lens.
03-02-2017, 06:49 AM   #11
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For sharpness - you can have a look at this pic, it looks very sharp to me (taken on a tripod, stacked in PS).
Bridge | Timur Dzhambinov | Flickr
03-02-2017, 08:06 AM   #12
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QuoteOriginally posted by Adam Quote
Every WR lens does this with the air. That's normal.

But I'd get the lens exchanged, as it sounds like it was somehow damaged in transit.
I wonder what happened to its original box - is this a returned lens, by chance?
That's why I prefer to buy from a trusted B&M store. But, I have one in the same town...
03-02-2017, 03:55 PM   #13
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QuoteOriginally posted by Kunzite Quote
I wonder what happened to its original box - is this a returned lens, by chance?
That's why I prefer to buy from a trusted B&M store. But, I have one in the same town...
Like I said.. the packager at B&H used a large shipping box to ship the smaller Pentax lens box and did so without much in the way of packing material. As a result, the lens had to have bounced around like a pinball inside of the larger shipping box throughout delivery. There is no notable damage to the Pentax product box. Only minor damage to the outer shipping box.


I've gone out and taking photos using this lens targeting a brick wall. Unless this lens is damaged, and it very well might be, I'd say it is not really sharp at either ends (on the edges and corners mostly) and has a lot of Chromatic Aberration on both ends of the focal range. Around 70mm (in the center of the range) this improves quite a bit and stopped down to f/8 it improves much more. Sharpness, as a whole, improves stopped down to around f/8 too, but seems to soften by f/11 a little.

Corners are still an issue. I think the CA is a part of the issue there.. Stopped down they improve, but not dramatically.

Center sharpness through about 2/3rds of the frame (if you made a circle starting from center of the image and worked out) is rather stellar though imo.

---------- Post added 03-02-17 at 05:04 PM ----------

http://www.swiftpic.org/image.uploads/02-03-2017/original-b889b4584fbcd2757afec723036f6a92.jpg 73mm f/8 on a tripod with a 2second timer and I think in LV at the time

About as good as it gets.
03-02-2017, 05:10 PM   #14
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The decentreing should consistently move when you first shoot in landscape, then portrait orientation.
03-02-2017, 06:04 PM   #15
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I'm not really sure it is decentered though.. might just be a soft copy.. might be entirely normal. I really don't know. But I've put in for an RMA and will ship it back shortly for an exchange. Hopefully they pack the box a bit better this time around (and the copy of the lens itself is improved).

It seems like buying lenses online is almost like a box of chocolates. haha
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