Forgot Password
Pentax Camera Forums Home
 

Reply
Show Printable Version Search this Thread
05-13-2015, 11:20 AM   #16
Forum Member




Join Date: Jul 2012
Location: Härjedalen, Sweden
Posts: 72
I've got a Hoya circ Pl filter that for some reason has got mottled and I can't get rid of it. My guess is that it is the coating and I can't see any other way to solve it than buying a new filter. Think I'll go with B/W this time.

05-13-2015, 11:42 AM   #17
Loyal Site Supporter
Loyal Site Supporter
BigMackCam's Avatar

Join Date: Mar 2010
Location: North-East of England
Posts: 15,231
Original Poster
QuoteOriginally posted by Samoht Quote
I've got a Hoya circ Pl filter that for some reason has got mottled and I can't get rid of it. My guess is that it is the coating and I can't see any other way to solve it than buying a new filter. Think I'll go with B/W this time.
Could be the coating, as you say, or possibly delamination?
05-13-2015, 12:37 PM   #18
Forum Member




Join Date: Jul 2012
Location: Härjedalen, Sweden
Posts: 72
Yes, delamination is a possible cause as well. Strange though since I haven't used it that much and has always been stored in its box. It's about two years old so not that old.
05-13-2015, 01:04 PM   #19
Loyal Site Supporter
Loyal Site Supporter
BigMackCam's Avatar

Join Date: Mar 2010
Location: North-East of England
Posts: 15,231
Original Poster
I had a no-name CPL filter start to delaminate within 6 - 8 months of me buying it. Uncommon, I know, but manufacturing defects do occur, though Hoya usually seems to be a good choice...

05-14-2015, 09:44 AM   #20
Site Supporter
Site Supporter




Join Date: Sep 2012
Location: Raleigh, NC, USA
Posts: 850
I had a protective filter on all my lenses. I read a super long article. I removed all filters. Makes no sense to put a $10 piece of glass in front of a $1000 piece of glass. Or even a plastic fantastic. I carry those single use lens wipes and a couple clean lens cloths at all times.

Pentax lenses compete with zeiss I feel it is counter productive to undo that.
05-14-2015, 10:55 AM   #21
Loyal Site Supporter
Loyal Site Supporter
BigMackCam's Avatar

Join Date: Mar 2010
Location: North-East of England
Posts: 15,231
Original Poster
QuoteOriginally posted by condor27596 Quote
... Makes no sense to put a $10 piece of glass in front of a $1000 piece of glass. Or even a plastic fantastic...
...
Pentax lenses compete with zeiss I feel it is counter productive to undo that.
It may be counter-productive, or it may not. Protective filters can serve a genuinely useful purpose for some people - albeit with trade-offs, which I fully acknowledge. Knowing when to remove them to avoid artefacts is key, I think.

I'll do some comprehensive A/B testing at some stage... for now, though, take a look at the attached crops in LR6...

I took two very quick photos of a bush in my garden, using my K3 with an old "Super Paragon" 28mm F2.8 at F5.6, ISO 200. I didn't choose to use this particular lens - it's just what I had on the camera. It's a perfectly decent little lens - not the sharpest or most contrasty, for sure, but it does the job. One of the photos was taken with a no-name, cheap and nasty, allegedly-MC UV filter fitted, and the other without. The crops are shown at 1:2 magnification - not an unreasonable size for printing, I think you'd agree. Bearing in mind very minor lighting and focusing differences, can you tell which is the shot taken WITH the filter - is it the first or second? If so, how can you tell? Even pixel-peeping at 1:1, I see very, very little difference between the two. Maybe the IQ in the photo taken WITH filter has been degraded... If it has, though, I can't see it.

I realise this isn't a scientifically-controlled test and the lighting conditions posed no risk of flare / ghosting, where a filter may have to be removed to get a decent result. Plus, I wasn't using one of my super-duper DA Limited lenses - just an inexpensive old thing I picked up on flea-bay. But I'd bet the same A/B test with my DA70 and a half-decent UV filter would yield similarly comparable results.

YMMV, of course
Attached Images
   
05-14-2015, 03:13 PM   #22
Pentaxian
lightbox's Avatar

Join Date: Mar 2015
Posts: 599
QuoteOriginally posted by BigMackCam Quote
Bearing in mind very minor lighting and focusing differences, can you tell which is the shot taken WITH the filter - is it the first or second? If so, how can you tell?
I think the first photo is the one with the filter, only because the stem appears sharper in the second photo (especially in the brown section where it's been cut).

However, that could just be focusing differences.

Definitely pixel-peeping territory...
05-14-2015, 05:44 PM   #23
Pentaxian
rburgoss's Avatar

Join Date: May 2008
Location: San Jose, Costa Rica
Photos: Gallery | Albums
Posts: 972
I can see the diagonal lines in the samples WITH FILTER.

What would be interesting to know, if such results happen with another camera (different model) or another camera (same model).

Also, since all diagonal "offending" lines seem to show about at the same angle test after test, It sounds logical to perform a series of Tests on which the filter is turned at leasr 1/4 turn each time. Do lines chane angle accordingly or stay the same?

So far the OP has proven "THE FILTER" is causing the problem. What I would like to know if such occurrence happens in the filter by itself or as a combination of this specific filter, a specific lens and a specific camera body.

05-15-2015, 05:44 AM   #24
Loyal Site Supporter
Loyal Site Supporter
BigMackCam's Avatar

Join Date: Mar 2010
Location: North-East of England
Posts: 15,231
Original Poster
QuoteOriginally posted by lightbox Quote
I think the first photo is the one with the filter, only because the stem appears sharper in the second photo (especially in the brown section where it's been cut).

However, that could just be focusing differences.

Definitely pixel-peeping territory...
Actually, the first one is WITHOUT the filter, and the second one WITH I think the slight difference in sharpness IS due to focusing distance - depending on exactly where in the crop you look, sometimes the first is sharper, sometimes the second.

But I hope the comparison showed those reading this thread that - in *this* isolated test, at least - IQ was not impacted by the UV filter (which isn't to say it wouldn't impact other test images)...

---------- Post added 05-15-2015 at 01:45 PM ----------

QuoteOriginally posted by rburgoss Quote
I can see the diagonal lines in the samples WITH FILTER.

What would be interesting to know, if such results happen with another camera (different model) or another camera (same model).

Also, since all diagonal "offending" lines seem to show about at the same angle test after test, It sounds logical to perform a series of Tests on which the filter is turned at leasr 1/4 turn each time. Do lines chane angle accordingly or stay the same?

So far the OP has proven "THE FILTER" is causing the problem. What I would like to know if such occurrence happens in the filter by itself or as a combination of this specific filter, a specific lens and a specific camera body.
Thanks for the response. In actual fact, I'm about to post a new thread, as I did some further testing with three different lenses and several filters this morning, so please look out for it if interested
09-09-2015, 03:14 PM   #25
Junior Member




Join Date: Jan 2014
Location: Maui, Hawaii
Posts: 46
I just encountered the same problem with a Hoya Alpha MC/UV filter.
Hopefully, I'll be able to return it for a refund.
09-09-2015, 11:46 PM   #26
Loyal Site Supporter
Loyal Site Supporter
BigMackCam's Avatar

Join Date: Mar 2010
Location: North-East of England
Posts: 15,231
Original Poster
QuoteOriginally posted by gmiyamoto Quote
I just encountered the same problem with a Hoya Alpha MC/UV filter.
Hopefully, I'll be able to return it for a refund.
Sorry to hear it. I've had good luck with all of my Hoya HMC UV(0) filters, but I guess there must be something in the raw materials or manufacturing process that means no brand is without some failures.
Reply

Bookmarks
  • Submit Thread to Facebook Facebook
  • Submit Thread to Twitter Twitter
  • Submit Thread to Digg Digg
Tags - Make this thread easier to find by adding keywords to it!
angle, attachment, bokeh, camera, da70, f2.4, f4, filter, filters, grass, image, k-mount, lawn, lens, lines, model, pattern, pentax lens, photo, photos, shot, shots, slr lens, test, uv
Thread Tools Search this Thread
Search this Thread:

Advanced Search


Similar Threads
Thread Thread Starter Forum Replies Last Post
B&H: How to Test Your Lens interested_observer Pentax SLR Lens Discussion 2 02-14-2015 11:36 AM
New IIs; What's your test checklist? fewayne Pentax K-5 16 05-19-2013 05:46 PM
Reminder: Always mount your lens hoods! L33tGreg Pentax SLR Lens Discussion 6 03-15-2012 04:00 PM
Streets Always wear your sunglasses KarenH Post Your Photos! 23 02-17-2011 02:14 AM
do you always straighten your photos in PP? aleonx3 Digital Processing, Software, and Printing 12 03-19-2010 04:55 PM



All times are GMT -7. The time now is 08:14 AM. | See also: NikonForums.com, CanonForums.com part of our network of photo forums!
  • Red (Default)
  • Green
  • Gray
  • Dark
  • Dark Yellow
  • Dark Blue
  • Old Red
  • Old Green
  • Old Gray
  • Dial-Up Style
Hello! It's great to see you back on the forum! Have you considered joining the community?
register
Creating a FREE ACCOUNT takes under a minute, removes ads, and lets you post! [Dismiss]
Top