Sunday, June 10, 2012

Filters for Protecting Lenses: High-End vs. Budget vs. Dirt-Cheap

With digital photography, using filters to achieve special effects has become much less common, with the exception of neutral density filters, graduated ND filters, and circular polarizers.  The other exception, with some controversy, is the use of filters to protect lenses.  Typically, UV filters or sometimes skylight (warming) filters are used for this purpose.

In this post, we compare images from lenses without any filter, with a budget filter, and a high-end filter.  The filters I tested were:
(a) a high-end filter, the Hoya HD Hardened Glass 8-layer Multi-Coated Digital UV Filter, around $70 for 77mm.
(b) a budget filter, the Hoya skylight filter (standard version, not multi-coated), around $20 for 77mm.  Note: the skylight filter has a warming effect, so for purposes of this comparison, please take that into account as part of the filter design and not an inherent characteristic of budget filters.
I've also included a separate test for an ultra-cheap generic UV filter.

I tested the filters on two lenses:
(i) a flare-resistant lens, the Nikkor 24-70 2.8G on a Nikon D3; and
(ii) a lens that is [supposedly] susceptible to flare and ghosting, the Tokina 11-16 2.8 on a Fuji S5 Pro.
Both lenses use 77mm filters so I was able to use the same set of filters for the tests.

Hit the jump for the samples.
NIKKOR 24-70 2.8G
For the first lens to test, I chose the Nikkor 24-70 2.8G because it has a nano-crystal coat, which reduces ghosting and flare.  The 24-70 thus represents a lens that is flare-resistant.  I tested two angles: one where the sun was directly in the middle of the frame and another where the sun was at the corner of the frame.  I didn't use the lens hood.  The images were taken in raw, but I applied no processing, so these are SOOC, at full resolution.  You can view the slideshow below or click here for the web album instead (the images are also downloadable).


Observation: In the first set of images with the camera directly facing the sun, the most noticeable differences are in the area above the window of the shed.  In the second set, with the sun at the corner, the most significant differences are near the corner of the house nearest the small window on the middle/left.

TOKINA 11-16 2.8
For the second lens, I tested the Tokina 11-16 because it is a wide angle lens and is reputedly prone to ghosting and flare.  You can view the slideshow below or click here for the web album instead (the images are also downloadable).


Note: in the last shot, with the sun at the corner and the budget filter, the exposure was 1/3 stop higher (must have accidentally nudged it).  Please take that into account.

Observation: In the first set of images with the camera directly facing the sun, the most noticeable differences are in the area above near the window of the shed. In the second set, with the sun at the corner, the most significant differences are near the small window on the middle/left and the lower right corner of the frame.

COMMENTS:
Personally, I was somewhat surprised that there was not a bigger difference between the budget filter and the high-end filter.  Kudos to Hoya for producing a budget filter with relatively good quality.  Nonetheless, I would much prefer to use the HD filter.  If the lens isn't expensive enough to justify the cost of the HD filter, I may as well not use a filter and just rely on the lens hood.  [On the other hand, if you are the type to frequently go into dusty or gritty environments, I could see how having at least the budget filter (if not the HD filter) on all your lenses.]

As between the HD filter and having no filter, I think the difference is small enough that I would prefer to have the HD filter for my more expensive lenses (e.g. 24-70 and 70-200).  If those lenses got damaged it would really make my heart sink, so the very slight image degradation is an acceptable tradeoff in my view.

GENERIC FILTERS
Oh yeah I did mention those ultra cheap filters, didn't I?  Just because the Hoya standard filter wasn't too bad, doesn't mean that you'll get the same results if you get an ultra-cheap generic Made-in-China filter.  I have tried those in the past and those will definitely reduce the contrast in your image.  Here are a couple of comparisons (no pixel peeping required).  These were from a Nikon D80 and a Tamron 28-75.
no filter

crappy filter

no filter

crappy filter
In fact, the shots above were the moment I realized how noticeably a crappy filter can affect the image and I stopped using filters for protection from that point forward until I got the HD filter for the 24-70.

BUYING FILTERS
One more word of advice: there are plenty of fake high-end filters out there.  I strongly recommend buying from a reputable seller to make sure you're getting the filter that you're paying for.  If you find one that's on sale for a substantially lower price, I would think twice about buying it.
I bought my Hoya HD filter from Amazon.  If you would like to support this blog by buying from Amazon as well, just click on this link.  You can also help our blog by sharing links to our posts in social media (Facebook, Twitter, Google Plus, etc.) or your website (if you have one).  Thank you for your support.

ADDITIONAL RESOURCES
Lenstip.com and Optyczne.pl tested and compared several UV filters here:
http://www.lenstip.com/113.1-article-UV_filters_test.html
http://www.lenstip.com/120.1-article-UV_filters_test_-_supplement.html (including the Hoya HD)