UV filter results in soft images?

Totality · 13 May 2008 at 17:31

Just wondering if anyone else has noticed this as I never seemed to notice it on my Canon 70-200mm L with a filter. I now have the 100-400mm L and bought a Hoya filter for it. Took some test photos and saw a kinda "ghost" image resulting in blur when cropped to 100%.

Is this normal? I was annoyed thinking I had a bad copy so took two sets of photos. Both at ISO 400 to get the speed up so ended up around 1/2000 at 400mm. IS was enabled but shouldnt have been needed at 1/2000 anyway but alas I was testing handheld shots. I took loads with each setting and they all came out the same for both sets as follows at 100% crop.

I'm using the Hoya 77mm Green series. Would the Pro 1 series being more expensive make a huge difference or are all filters just soft?

Without the filter:

With the Hoya UV filter in use:

Totality · 13 May 2008 at 18:03

The other filter I had was just a plain glass one - no UV - I've just remembered.

Dont have it anymore so cant test. It was a Canon one and not a Hoya!

Totality · 13 May 2008 at 18:08

Unfortunately from the net. I've been reading up on it and it looks like cheapy filters (like the Hoya green series) can soften images. Was just wondering if anyone had any experience of the expensive filters.

Totality · 13 May 2008 at 18:33

Concorde Rules said:
I had the best 58mm Hoya UV on my 70-300, made it AF badly and very soft.

AVOID filters on zooms at all costs tbh, hell avoid any apart from ND/CPL/etc

If its damage you want to prevent, use the lens hood.

Will do! I'm glad I did the testing today when the filter arrived rather than at an event. Was just plain fluke I decided to test at 100% with the filter attached because I was actually testing the sharpness of the lens at 400mm wide open and it was nothing to do with the filter!

Totality · 13 May 2008 at 20:51

Just been doing some more tests using the 18-55mm kit lens which I never bought a filter for as its so cheap and the 50mm F1.8.

When using a filter the 50mm is as soft as the kit lens!! Seems like everything else in photography I'm going to have to splash out money to get better results. Didnt think a piece of glass would have so much effect

MK - Do you use the B+W F- Pro UV 010 filters? Not bothered about the 50mm getting damaged as its the same price as an expensive filter! But want one for the 100-400mm to protect it from sand, etc when out in the elements

Totality · 13 May 2008 at 22:23

Will test again in a few weeks when the B+W one arrives. Only getting one for the 100-400mm as the 50mm F1.8 is so cheap its not worth spending loads on a filter. I've taken the cheap Hoya one off as the results were as follows at ISO 400 about 1.5m away - again at 100% crop...

With the filter:

Without the filter:

Totality · 15 May 2008 at 00:21

Since posting this I've been on POTN and talkphotography and there are lots of threads about cheap filters like the Hoya green series causing image problems.

Seems like anything else in photography you have to spend big to get nice photos! At least I found all this out whilst testing rather than at an actual event