The point is that UV filters don't provide any benefit for digital cameras,
Actually, this thread quickly degenerated, as usual. UV filters do offer additional UV filtering. It would be interesting to see if in high altitude conditions, for example, this is noticeable.
The original question was whether or not UV filters are necessary. I think discussing the pros and cons of UV filters is on topic, and not "degeneration"
and may noticeably degrade the image.
Why use a product that at best does no harm?
I am not a big fan of UV filters. I own 5 lenses currently and two of them have filters. Why use them?
- may keep dust away with my 17-55 (no dust so far). This increases resale value, and may actually improve IQ if it indeed, keeps dust way.
Thanks for posting your reasons for using filters. I think it is more educational to have actual examples to discuss.
I assume you are referring to internal dust, as exterior dust can be easily wiped off.
Most lenses are not weather sealed, and dust can enter through many avenues. Obviously, dust does not pass though the front element of the lens. I suspect you are worried about dust passing around the edges of the front element. My suspicion is that dust entering through various openings in the barrel are far more of an issue. Many lenses change their length (and internal volume) as they focus and/or zoom. As the volume changes, air must pass in or out of the barrel. This is the easiest way for dust to enter a lens. A filter doesn't stop this.
If you could stop the air exchange, then the lens would not be able to focus. Your best bet to stop this sort of dust intrusion is to place a protective barrier around the lens. A baggie will work (with an opening cut out for the front element), or some sort of filter material that allows air to pass, and not dust.
Thus I don't think the filter is giving you the sort of dust protection you desire.
Even if we assume that a filter does give you dust protection, then the question is which affects image quality more - a little bit of dust inside the lens, or a filter?
- I tend to bump my 70-200 too often; the filter on front has several marks on the ring already. It makes me feel better knowing that there is a filter there.
Again, there is something to this claim. For some people it is worth trading a little image quality to preserve the cosmetic finish on the front of the lens and/or your piece of mind.
Personally, I think you would be far better off with a lens hood. The lens hood provides much better protection to the lens barrel and never reduces image quality.
To me it seems that lens hood is a much better choice than a filter.
On the other hand, some people won't remember to put on the hood, they leave the filter on all the time and forget about it.
Again, it's a personal decision whether or not the convenience of the filter justifies the cost in IQ. (depending on your shooting circumstance, the IQ cost might be very low).
- B+W filters can be cleaned much easier than any lens I own, especially for fingerprints, smudges, etc. This may increase IQ.
Now we are getting to some tricky questions. If you are much better at cleaning a filter than a lens, then perhaps the filter is the right choice for you. Keep in mind that a filter is further forward and tends to get dirtier faster than the lens alone.
On the other hand, the coatings on your lens are probably higher quality than the coatings on your filter. The lens might stand up to repeated cleanings much better than the filter.
So yes, there are advantages to filters. Depending on your circumstances, the filter may be the right choice for you.
We all have different workflows.
I think it's important to understand the benefits and costs or filters so you can make a decision that right for your situation.
but never forget the hood on your lenses when using them!
