UV filters :( Check this out.

[setaside2]

Re: UV filters Check this out.

Absolutely! It's no longer just to protect! It keeps your image quality up as well.

And consider, really, if you just bought that $1500 lens, are you REALLY going to put that $15 piece of plate glass in front of it? WHY?! I get in this discussion constantly at my store.... Why compromise your lens?

Thanks for the post, Stephen. I have a link to send my naysayers!

[Ian]

Re: UV filters Check this out.

Indeed it is revealing Dennis. At present I don't have any filters on my lenses, and it is essentially for this reason. All my lenses use a 77mm thread and to buy a quality filter of that size is rather pricey. Don't think because its Hoya you are OK either, because there are different qualities of Hoya filters and the best ones are very expensive. However I did once read of this phenomena with some UV filters, so took the one I had off, and I've never used one since. This is not to say that you or anyone else should have a noticeable difference in image quality.

I've found though that they don't stop dust on the lens, you still have to dust the front element from time to time. Also I find using a lens hood protects the lens from bumps etc. The same principle applies to the likes of Cokin type filters. When I wanted a ND Grad filter set, I bought Lee. I just had no confidence in the much cheaper Cokin ones.

Several of my lenses use a 67mm filter size and while I was in Hong Kong I bought a circular polariser. It was a third of the price it would have been at Jessops here in the UK.

Normally, I would cut some slack to the hard-up UK retailers, but how can anyone explain a 200% difference in price on a product like this, that requires no after sales care or maintenance?

By the way, Stephen, my experience with Kenko has always been positive. So I think you have merely experienced the fact that filters are, inherently, an optical compromise.

Ian

[Stephen]

Re: UV filters Check this out.

By the way, Stephen, my experience with Kenko has always been positive. So I think you have merely experienced the fact that filters are, inherently, an optical compromise.

Ian

You almost seem to be saying that the image quality using the Kenko UV filter is acceptable

[Ian]

Re: UV filters Check this out.

You almost seem to be saying that the image quality using the Kenko UV filter is acceptable

Well, having read the rest of the thread, maybe you have a duff one, but Kenko is not a 'cheap and nasty' brand (It's part of the Tokina group of companies), so you should be getting results similar to other good brands.

I think you have reproduced a tightly cropped portion of your test images to clearly show the differences, but I don't know how much Patrick cropped his examples?

I'd also repeat the test, with a tripod and with IS switched off.

Having looked at your test results again, there seems to be an astigmatic effect, so there is reduced sharpness much more in one axis. Horizontal detail is much more blurred than vertical detail. I'm now wondering if the effect is more to do with the IS operation than the filter

Ian

[Stephen]

Re: UV filters Check this out.

Well, having read the rest of the thread, maybe you have a duff one, but Kenko is not a 'cheap and nasty' brand (It's part of the Tokina group of companies), so you should be getting results similar to other good brands.

I think you have reproduced a tightly cropped portion of your test images to clearly show the differences, but I don't know how much Patrick cropped his examples?

I'd also repeat the test, with a tripod and with IS switched off.

Having looked at your test results again, there seems to be an astigmatic effect, so there is reduced sharpness much more in one axis. Horizontal detail is much more blurred than vertical detail. I'm now wondering if the effect is more to do with the IS operation than the filter

Ian

I can only say the images shown are a with and without the filter comparison and when I've tried the same exercise with a Hoya UV there was no noticeable loss in quality. Therefore I can only assume that the massive difference with the Kenko is down to the quality of the glass. Lets be honest here, this was a giveaway filter, and one can only guess that if it were the best that Kenko can offer it wouldn't be given away. As I mentioned also, even looking through the viewfinder one was able to detect some loss of sharpness, which at first I put down to the viewfinder being oof, but this was not the case. I really can't find it within myself to stick up for this item as you seem to be doing

Perhaps I'll contact Jim and ask him to send it back for you to have a look at. I think he must be away at present though.

[Ian]

Re: UV filters Check this out.

I can only say the images shown are a with and without the filter comparison and when I've tried the same exercise with a Hoya UV there was no noticeable loss in quality. Therefore I can only assume that the massive difference with the Kenko is down to the quality of the glass. Lets be honest here, this was a giveaway filter, and one can only guess that if it were the best that Kenko can offer it wouldn't be given away. As I mentioned also, even looking through the viewfinder one was able to detect some loss of sharpness, which at first I put down to the viewfinder being oof, but this was not the case. I really can't find it within myself to stick up for this item as you seem to be doing

Perhaps I'll contact Jim and ask him to send it back for you to have a look at. I think he must be away at present though.

No problem, Stephen - I can of course test the filter using test charts.

But certainly in the original test you did, there were some factors that needed to be filtered ( geddit!) out (certainly the use of IS and - I assume - not using a tripod) and I can clearly see that the blur is more in one plane than another, which can be explained by camera movement.

I did feel the need to point out that Kenko is not a cheap brand It's a well respcted brand in Japan and as part of the Tokina group, I can't believe product quality would be an issue.

Of course, there may be a chance that the filter you have is a 'fake' - branded Kenko but actually made by a cheap outfit in China - but that's pure speculation!

Ian

[Ian]

Re: UV filters Check this out.

No problem, Stephen - I can of course test the filter using test charts.

But certainly in the original test you did, there were some factors that needed to be filtered ( geddit!) out (certainly the use of IS and - I assume - not using a tripod) and I can clearly see that the blur is more in one plane than another, which can be explained by camera movement.

I did feel the need to point out that Kenko is not a cheap brand It's a well respcted brand in Japan and as part of the Tokina group, I can't believe product quality would be an issue.

Of course, there may be a chance that the filter you have is a 'fake' - branded Kenko but actually made by a cheap outfit in China - but that's pure speculation!

Ian

Stephen, can you remember if it was branded a 'Pro' filter like these:

http://www.kenko-tokina.co.jp/e/P.12_13.PDF

Ian

[Stephen]

Re: UV filters Check this out.

But certainly in the original test you did, there were some factors that needed to be filtered ( geddit!) out (certainly the use of IS and - I assume - not using a tripod) and I can clearly see that the blur is more in one plane than another, which can be explained by camera movement.


Ian

For the sake of being scientific about this, I'd accept the point about filtering out some anomalies such as IS and using a tripod.

The thing is though, that this was intended as a 'real world' test. The image I showed was one of several taken and found to be all the same in terms of the quality, or lack of it. The comparison shot was taken straight after, using the same MO. Now if I was to take the IS off and use a tripod, it seems to kinda defeat the object of having such a lens. This was originally intended as a test of the IS as much as the filter, and if I thought the poor image quality was a result of the IS I'd be really *issed off I know though that in use so far the lens has shown itself to produce a quality result. I used it only yesterday on a job and the result was stunning.

[Ian]

Re: UV filters Check this out.

For the sake of being scientific about this, I'd accept the point about filtering out some anomalies such as IS and using a tripod.

The thing is though, that this was intended as a 'real world' test. The image I showed was one of several taken and found to be all the same in terms of the quality, or lack of it. The comparison shot was taken straight after, using the same MO. Now if I was to take the IS off and use a tripod, it seems to kinda defeat the object of having such a lens. This was originally intended as a test of the IS as much as the filter, and if I thought the poor image quality was a result of the IS I'd be really *issed off I know though that in use so far the lens has shown itself to produce a quality result. I used it only yesterday on a job and the result was stunning.

I perfectly understand, Stephen, just that with my product tester hat on, I wouldn't be comfortable with the procedure - which I'm sure you will understand too.

I'm really keen to have look at this filter now!

Ian

PS I'm one of those who prefers not to use a filter because adding an extra couple of glass to air surfaces in the optical stack can only be detrimental (if normally only to a small degree) to overall lens performance.

[Stephen]

Re: UV filters Check this out.

Stephen, can you remember if it was branded a 'Pro' filter like these:

http://www.kenko-tokina.co.jp/e/P.12_13.PDF

Ian

It certainly didn't come in a box that resembled anything on that PDF as I recall, and Tokina was not referred to on the box either. I can't help wondering now if it was a cheap copy as you suggested

[setaside2]

Re: UV filters Check this out.

Myself, I have three circular polarizers. I chose B+W after mucking about with a bunch of different brands. That's the advantage of working in a camera store...

Anyway, the revealing thing was that filters are most certainly NOT made equal. I had extravagant differences from bottom to top in the polarizer class. I don't use UVs, I spend to much time in the field and therefore my polarizer pretty much suffices where a UV would normally have been.

But I can tell you that in my personal experience, the color and light transmission and, therefore, the upkeep in detail and contrast and edge separation were far superior when I hit the top of the line. The glass and the coatings used on said optic were of the quality I would expect from my pro lenses.

That said, I've also found out on numerous unfortunate occasions that the B+W filters happen to be pretty darned indestructible! oops.

Well worth the money, IMHO.

Also, though I don't own them, several friends of mine use Heliopan slimlines and they are gorgeous polarizers. a BIT dear, I might add, but lovely. Recommended as well.

As for the Hong Kong thing... well I've come to understand that the quality of product is not always the same around the world and is, in some cases, not the same product at all. That may not be the case here, there are always good deals to be had... just a caveat to the global shopper.

[StuartR]

Re: UV filters Check this out.

This thread has prompted me to test my EF-S 60mm f/2.8 macro lens. 250 quids worth of lens and I stuck a 10 year old Jessops (not a Hoya as mentioned in another post) 1A filter on it rather than buy a new UV filter

Anyway, can you tell which one is with and which is without? Both images shot in RAW using a tripod a timer release, processed exactly the same via DxO and then PhotoShop for a quick smart sharpen. The differences are subtle but I know which one I prefer - the one with the filter!

[Stephen]

Re: UV filters Check this out.

This thread has prompted me to test my EF-S 60mm f/2.8 macro lens. 250 quids worth of lens and I stuck a 10 year old Jessops (not a Hoya as mentioned in another post) 1A filter on it rather than buy a new UV filter

Anyway, can you tell which one is with and which is without? Both images shot in RAW using a tripod a timer release, processed exactly the same via DxO and then PhotoShop for a quick smart sharpen. The differences are subtle but I know which one I prefer - the one with the filter!

You suprise me actually Stuart, esp as I was going to say I prefer the one without. Not only that but somehow it seems to me that the colour tinge that the filter creates is something I don't want, esp as the principle of using Raw is somehow negated. However this is not to say that under certain conditions the filter may have a beneficial effect

[peter]

Re: UV filters Check this out.

Big write up about filters in the June issue of Digital Camera. Oh and Stephen a new advert for the canon 1d mk3, looks like the main selling point maybe something that has not been talked about much turns out it has a remastered neck strap .