CA with 35mm limited

yorik · 01-31-2012, 05:52 PM

Hi - this is my first post to the forums, I'm a Pentax newbie...

I recently bought a K-5 and the 35mm limited after reading a lot about both, and
I am very happy with my decision... BUT, one of the oft-repeated positive comments
about this lens is its strong resistance to CA (`purple fringing', I assume). This includes
comments by one reviewer in the lens-review data base, who claimed he hadn't (yet)
been able to induce PF.

My question is this: since my copy of the lens seems to exhibit PF in all the usual
circumstances (without any particular effort on my part), e.g., back-lit branches, might
this mean that I have a flawed copy of the lens? Or are the `resistance to CA' comments
somewhat overly enthusiastic? In other words, how much PF is too much for the 35 limited?

I have about 10 days before my 30-day return window (to B&H) expires, and I wonder whether
I should exchange the lens...

Thanks for any and all input!

joe.penn · 01-31-2012, 06:16 PM

Originally posted by yorik

My question is this: since my copy of the lens seems to exhibit PF in all the usual
circumstances (without any particular effort on my part), e.g., back-lit branches, might
this mean that I have a flawed copy of the lens? Or are the `resistance to CA' comments
somewhat overly enthusiastic? In other words, how much PF is too much for the 35 limited?

One of the MOST COMMON PF situations you will see is backlit branches, especially if the branches are gray - to give you an example, take a look at this pic -> https://www.pentaxforums.com/forums/post-your-photos/173314-nature-barred-owl.html

So, to answer your question, no need to be alarmed - if shooting other things that are low contrast and you get the same results, then you got an issue somewhere.

Can you post some examples?

v5planet · 01-31-2012, 06:50 PM

Example photos would be helpful. I've only been able to generate easily visible chromatic aberrations with my 35Ltd a couple times, and they were in pretty torturous conditions (brightly lit spider web against dark forest background).

yorik · 01-31-2012, 07:12 PM

I guess that my concerns were premature, (fueled in part by this being the first
time I spent $500+ on a lens). All of the cases of PF that I noticed were definitely
high contrast/strong back-light situations.

Thank you for your replies!

lytrytyr · 01-31-2012, 08:12 PM

Originally posted by v5planet

I've only been able to generate easily visible chromatic aberrations with my 35Ltd a couple times, and they were in pretty torturous conditions (brightly lit spider web against dark forest background).

FYI, here's a sample 100% crop of that kind of situation, taken with the DA35/2.8 Macro

yorik · 01-31-2012, 08:45 PM

Seeing no blatant PF in the photo above, here are a couple of examples (crops) of what I'm talking about. The
last one is admittedly extreme (the frame of a fluorescent light box), but still - it looks like someone traced
around the edge with a purple marker... is this to be expected in this situation?

calsan · 01-31-2012, 08:46 PM

With reference to spider web photo: eh?

Where?

I can see some purple, but it seems to me that its the spider web itself refracting the light???

With reference to Yorik : My DA 35 limited has nothing like that. My vote would be for a return.

normhead · 01-31-2012, 08:59 PM

I myself have returned a lens for just such an issue. DIfferent lens, different manufacturer, but... you have to know what you can live with. Since it was my second copy of said lens I actually changed manufacturers when I did my exchange. I took one of the 40km sign in my driveway (40 km , black on white, in bright sun) ) and there was a purple band one side of the 40, just like on your fluorescent light. I do take the odd pictures with road signs in them and I'm not wanting to have to throw them out.

lytrytyr · 01-31-2012, 09:01 PM

Originally posted by yorik

Seeing no blatant PF in the photo above, here are a couple of examples (crops) of what I'm talking about. The
last one is admittedly extreme (the frame of a fluorescent light box), but still - it looks like someone traced
around the edge with a purple marker... is this to be expected in this situation?

Ouch! That looks more like what Photozone caught on the FA77/K10D combination:
Pentax SMC-FA 77mm f/1.8 Limited - Review / Test Report - Analysis

I don't recall seeing anything that bad with my DA35 Macro on a K-x.

You'd probably do well to return your copy.

lytrytyr · 01-31-2012, 09:03 PM

Originally posted by calsan

With reference to spider web photo: eh?

Where?

I can see some purple, but it seems to me that its the spider web itself refracting the light???

Exactly. Point being that the DA35 Macro should be able to handle that kind of situation with aplomb.

v5planet · 01-31-2012, 09:41 PM

Originally posted by yorik

Seeing no blatant PF in the photo above, here are a couple of examples (crops) of what I'm talking about. The
last one is admittedly extreme (the frame of a fluorescent light box), but still - it looks like someone traced
around the edge with a purple marker... is this to be expected in this situation?

Some of that PF looks pretty bad. How heavily cropped are these? I have found a couple photos with my 35 that show PF in similar situations when zoomed way in, but are not noticeable at normal viewing size without close scrutiny.

yorik · 02-01-2012, 08:40 AM

Here are non-zoomed-in examples... The PF is still fairly clear in both.

Both pictures were shot wide open at an upward angle.

joe.penn · 02-01-2012, 09:06 AM

The first photo posted, the PF is to be expected as the photo is wayyyyyyyyyyy blown, exposure is way off - with the second photo I can not say "f'd up or not" as I have never shot a subject similar to that. You can take a shot and send it back to B&H and have it replaced - if you do have it replaced, please shoot these same subjects with the new one under the same exposure settings and post the results so we can compare...

lytrytyr · 02-01-2012, 10:39 AM

Here's the closest fluorescent light image I have with the DA 35 Macro,
again taken inside a big room, 100% crop from the image edge (f/4):

No bad PF, just the expected competence from a capable lens.

So alas, poor yorik, more evidence that you need to send your copy back.

yorik · 02-01-2012, 10:48 AM

With regards to the branches - that was my initial assessment, that the exposure was way off, especially since in other pictures
from the same sequence (that were more properly exposed. I was experimenting) I couldn't detect any PF. The light-box, on the
other hand was more troubling since the exposure as a whole didn't appear to be extremely off to me... However, I haven't
used a hand held light-meter since the early 70s, so my judgement of what constitutes borderline vs totally blown exposure is
highly suspect, to say the least.

So, with the additional information and pictures, what would you (all) conclude about the quality of the lens (or lack thereof)?

And, thank you all, by the way, for all the helpful and prompt input!

01-31-2012, 05:52 PM	#1
yorik Veteran Member Join Date: Jan 2012 Location: Scotts Valley, CA Photos: Gallery Posts: 991	CA with 35mm limited Hi - this is my first post to the forums, I'm a Pentax newbie... I recently bought a K-5 and the 35mm limited after reading a lot about both, and I am very happy with my decision... BUT, one of the oft-repeated positive comments about this lens is its strong resistance to CA (`purple fringing', I assume). This includes comments by one reviewer in the lens-review data base, who claimed he hadn't (yet) been able to induce PF. My question is this: since my copy of the lens seems to exhibit PF in all the usual circumstances (without any particular effort on my part), e.g., back-lit branches, might this mean that I have a flawed copy of the lens? Or are the `resistance to CA' comments somewhat overly enthusiastic? In other words, how much PF is too much for the 35 limited? I have about 10 days before my 30-day return window (to B&H) expires, and I wonder whether I should exchange the lens... Thanks for any and all input!

01-31-2012, 08:45 PM	#6
yorik Veteran Member Join Date: Jan 2012 Location: Scotts Valley, CA Photos: Gallery Posts: 991 Original Poster	Seeing no blatant PF in the photo above, here are a couple of examples (crops) of what I'm talking about. The last one is admittedly extreme (the frame of a fluorescent light box), but still - it looks like someone traced around the edge with a purple marker... is this to be expected in this situation? Last edited by yorik; 02-21-2014 at 10:13 PM.

02-01-2012, 08:40 AM	#12
yorik Veteran Member Join Date: Jan 2012 Location: Scotts Valley, CA Photos: Gallery Posts: 991 Original Poster	Here are non-zoomed-in examples... The PF is still fairly clear in both. Both pictures were shot wide open at an upward angle. Last edited by yorik; 02-21-2014 at 10:13 PM.

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01-31-2012, 06:16 PM	#2
joe.penn Veteran Member Join Date: Mar 2011 Location: Maryland (Right Outside Washington DC) Photos: Gallery \| Albums Posts: 2,902	Originally posted by yorik My question is this: since my copy of the lens seems to exhibit PF in all the usual circumstances (without any particular effort on my part), e.g., back-lit branches, might this mean that I have a flawed copy of the lens? Or are the `resistance to CA' comments somewhat overly enthusiastic? In other words, how much PF is too much for the 35 limited? One of the MOST COMMON PF situations you will see is backlit branches, especially if the branches are gray - to give you an example, take a look at this pic -> https://www.pentaxforums.com/forums/post-your-photos/173314-nature-barred-owl.html So, to answer your question, no need to be alarmed - if shooting other things that are low contrast and you get the same results, then you got an issue somewhere. Can you post some examples?

01-31-2012, 06:50 PM	#3
v5planet Veteran Member Join Date: Jan 2010 Location: Seattle Photos: Albums Posts: 1,915	Example photos would be helpful. I've only been able to generate easily visible chromatic aberrations with my 35Ltd a couple times, and they were in pretty torturous conditions (brightly lit spider web against dark forest background).

01-31-2012, 07:12 PM	#4
yorik Veteran Member Join Date: Jan 2012 Location: Scotts Valley, CA Photos: Gallery Posts: 991 Original Poster	I guess that my concerns were premature, (fueled in part by this being the first time I spent $500+ on a lens). All of the cases of PF that I noticed were definitely high contrast/strong back-light situations. Thank you for your replies!

01-31-2012, 08:12 PM	#5
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by v5planet I've only been able to generate easily visible chromatic aberrations with my 35Ltd a couple times, and they were in pretty torturous conditions (brightly lit spider web against dark forest background). FYI, here's a sample 100% crop of that kind of situation, taken with the DA35/2.8 Macro

01-31-2012, 08:46 PM	#7
calsan Pentaxian Join Date: Nov 2008 Location: Perth, Australia Photos: Gallery Posts: 1,548	With reference to spider web photo: eh? Where? I can see some purple, but it seems to me that its the spider web itself refracting the light??? With reference to Yorik : My DA 35 limited has nothing like that. My vote would be for a return.

01-31-2012, 08:59 PM	#8
normhead Pentaxian Join Date: Jun 2007 Location: Near Algonquin Park Photos: Gallery \| Albums Posts: 40,451	I myself have returned a lens for just such an issue. DIfferent lens, different manufacturer, but... you have to know what you can live with. Since it was my second copy of said lens I actually changed manufacturers when I did my exchange. I took one of the 40km sign in my driveway (40 km , black on white, in bright sun) ) and there was a purple band one side of the 40, just like on your fluorescent light. I do take the odd pictures with road signs in them and I'm not wanting to have to throw them out.

01-31-2012, 09:01 PM	#9
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by yorik Seeing no blatant PF in the photo above, here are a couple of examples (crops) of what I'm talking about. The last one is admittedly extreme (the frame of a fluorescent light box), but still - it looks like someone traced around the edge with a purple marker... is this to be expected in this situation? Ouch! That looks more like what Photozone caught on the FA77/K10D combination: Pentax SMC-FA 77mm f/1.8 Limited - Review / Test Report - Analysis I don't recall seeing anything that bad with my DA35 Macro on a K-x. You'd probably do well to return your copy.

01-31-2012, 09:03 PM	#10
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Originally posted by calsan With reference to spider web photo: eh? Where? I can see some purple, but it seems to me that its the spider web itself refracting the light??? Exactly. Point being that the DA35 Macro should be able to handle that kind of situation with aplomb.

01-31-2012, 09:41 PM	#11
v5planet Veteran Member Join Date: Jan 2010 Location: Seattle Photos: Albums Posts: 1,915	Originally posted by yorik Seeing no blatant PF in the photo above, here are a couple of examples (crops) of what I'm talking about. The last one is admittedly extreme (the frame of a fluorescent light box), but still - it looks like someone traced around the edge with a purple marker... is this to be expected in this situation? Some of that PF looks pretty bad. How heavily cropped are these? I have found a couple photos with my 35 that show PF in similar situations when zoomed way in, but are not noticeable at normal viewing size without close scrutiny.

02-01-2012, 09:06 AM	#13
joe.penn Veteran Member Join Date: Mar 2011 Location: Maryland (Right Outside Washington DC) Photos: Gallery \| Albums Posts: 2,902	The first photo posted, the PF is to be expected as the photo is wayyyyyyyyyyy blown, exposure is way off - with the second photo I can not say "f'd up or not" as I have never shot a subject similar to that. You can take a shot and send it back to B&H and have it replaced - if you do have it replaced, please shoot these same subjects with the new one under the same exposure settings and post the results so we can compare...

02-01-2012, 10:39 AM	#14
lytrytyr Pentaxian Join Date: Nov 2011 Photos: Gallery \| Albums Posts: 4,310	Here's the closest fluorescent light image I have with the DA 35 Macro, again taken inside a big room, 100% crop from the image edge (f/4): No bad PF, just the expected competence from a capable lens. So alas, poor yorik, more evidence that you need to send your copy back.

02-01-2012, 10:48 AM	#15
yorik Veteran Member Join Date: Jan 2012 Location: Scotts Valley, CA Photos: Gallery Posts: 991 Original Poster	With regards to the branches - that was my initial assessment, that the exposure was way off, especially since in other pictures from the same sequence (that were more properly exposed. I was experimenting) I couldn't detect any PF. The light-box, on the other hand was more troubling since the exposure as a whole didn't appear to be extremely off to me... However, I haven't used a hand held light-meter since the early 70s, so my judgement of what constitutes borderline vs totally blown exposure is highly suspect, to say the least. So, with the additional information and pictures, what would you (all) conclude about the quality of the lens (or lack thereof)? And, thank you all, by the way, for all the helpful and prompt input!