Use of UV filters
 

I would like to see the pro's and cons of a UV filter or some other "lens protecting" glass on a lens.

The small ghosts on very high contrast shots suggests that this is not a good idea. It has to degenerate even normal images.


w..

Use of UV filters
 

Walter Banks wrote:

I would like to see the pro's and cons of a UV filter or some other "lens protecting" glass on a lens.

The small ghosts on very high contrast shots suggests that this is not a good idea. It has to degenerate even normal images.


It sounds as though you have already drawn your own conclusions, so
what would be the point in replying?

Use of UV filters
 

Walter Banks wrote:
I would like to see the pro's and cons of a UV filter or some other
"lens protecting" glass on a lens.

The small ghosts on very high contrast shots suggests that this is
not a good idea. It has to degenerate even normal images.

1. No filter at all, or
2. MC filters and
3. Clear glass (not UV/not Skylight).

For my 135 f/1.8 which has a 77mm front element I decided to add such
and bought a Nikon MC clear glass filter.

My Maxxum 7D, equipped with a Minolta flash is therefore a

Minolta/Konica-Minolta/Sony/Carl-Zeiss/Nikon hybrid.

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Use of UV filters
 

"Walter Banks" wrote in message
...
I would like to see the pro's and cons of a UV filter or some other "lens
protecting" glass on a lens.

The small ghosts on very high contrast shots suggests that this is not a
good idea. It has to degenerate even normal images.


w..



Every piece of glass in the light path has some effect on the image.

On the other hand, if something scratches the front of the lens, would you
prefer that scratch on an easily replaceable filter, or an expensive lens.
Yes, I know that good quality filters are expensive, but they would be less
expensive than the lens itself.

You pays your money and you takes your choices.

Use of UV filters
 

Walter Banks wrote:
I would like to see the pro's and cons of a UV filter or some other "lens protecting" glass on a lens.

The small ghosts on very high contrast shots suggests that this is not a good idea. It has to degenerate even normal images.
\

For my druthers, the lens hood always in place gives better protection.
At least for me, and the way I use my equipment.

--
john mcwilliams

Use of UV filters
 

"Ken Hart1" wrote in message
news:7wExk.938$Wd.262@trnddc01...

"Walter Banks" wrote in message
...
I would like to see the pro's and cons of a UV filter or some other "lens
protecting" glass on a lens.

The small ghosts on very high contrast shots suggests that this is not a
good idea. It has to degenerate even normal images.


w..



Every piece of glass in the light path has some effect on the image.

On the other hand, if something scratches the front of the lens, would you
prefer that scratch on an easily replaceable filter, or an expensive lens.
Yes, I know that good quality filters are expensive, but they would be
less expensive than the lens itself.

You pays your money and you takes your choices.

For better than 20 years I serviced both 35mm and most medium format
systems. I can say that in a small percentage of all the lenses I have
repaired (less then 20%) I have seen "protection" filters break into the
front element of the lens scratching it. Hoods generally offer better impact
protection. IMO

Use of UV filters
 

"mj" wrote:

For better than 20 years I serviced both 35mm and most medium format
systems. I can say that in a small percentage of all the lenses I have
repaired (less then 20%) I have seen "protection" filters break into the
front element of the lens scratching it. Hoods generally offer better impact
protection. IMO


How much protection does a hood offer against damaging the front
element of the lens through careless cleaning?

A filter is extremely easy to clean. You can even take it off the
lens to clean it. If you scratch or damage a filter, it is quick and
relatively cheap to replace. Try doing that with the front element of
a good quality lens, and you will be faced with a very large bill.

[Of course you could always sell it on eBay, claiming that the
defective front element did not affect the quality of the images
produced ... funny how many lenses on eBay are thus described!]

With film, the often alleged optical degradation through using a
filter was a non-issue as long as good quality multi-coated filters
were used. However, things have changed a little with digital because
of the greater reflectivity of the digital sensor. Whether the latest
filter coatings have made this a non-issue once again is a moot point.

Use of UV filters
 

mj wrote:
You pays your money and you takes your choices.

For better than 20 years I serviced both 35mm and most medium format
systems. I can say that in a small percentage of all the lenses I have
repaired (less then 20%) I have seen "protection" filters break into the
front element of the lens scratching it. Hoods generally offer better impact
protection. IMO


You need very careful to understand the implications of that statistic.

As a lens repair person you say you see 20% of lenses where the filter
has damaged the lens. I don't dispute that at all. But it does *not*
mean that 20% of the lenses which have UV filters suffer such damage.
Most people, who damage their filters will do it in a far less
catastropic manner. They are likely to put a scratch on the filter,
replace the filter and not send the lens for repair.

Also, whilst I accept filters can damage the lens if hit sufficiently
hard, one would have to question whether the lens would have been
damaged anyway without the filter. If a knock is sufficient to damage a
filter and smash it into a lens, it must have taken quite a knock -
quite possibly enough to have damaged the lens anyway.

I personally tend to use filters all the time. I might make an exception
on my Nikon macro lens though. The front element is very well recessed,
making damage to the element unlikely. Whilst I have never proved this,
I suspect a filter is more likely to degrade an image if the object is
focused very close, which is what one is likely to do on a macro lens.

But since the element on the micro nikkor lens is very well recessed, it
will be difficult to clean, so perhaps there is a good reason to buy a
UV filter.

Scratches on lens elements have a very significant effect on resale
value. There is for example a Nikon 600 mm lens for sale:

http://cgi.ebay.com/ws/eBayISAPI.dll...m=220278589593

This would be perfect for me.

* Just the lens I am looking for.
* Seller is only 40 miles away.
* Seller happy for me to pick it up.
* I can avoid the very significant risks of Paypal on items over $2000.

But that 600mm lens has a small scratch on the front element, and is a
bit tatty in places. Whilst I did bid, I am not going to bid again. It
has reached $4900 which I feel is enough for a lens with a scratch on
it. Had the condition been better, I would certainly have bid a lot
more, especially as it is very local to me.



I would rather see an auction where the seller says "has had a UV filter
on from day one" than "has a small scratch but does not degrade image".
Clearly scratches are more likely to cause problems when shooting into
the light.

Use of UV filters
 

Ken Hart1 wrote:
"Walter Banks" wrote in message
...
I would like to see the pro's and cons of a UV filter or some other "lens
protecting" glass on a lens.

The small ghosts on very high contrast shots suggests that this is not a
good idea. It has to degenerate even normal images.


w..



Every piece of glass in the light path has some effect on the image.

On the other hand, if something scratches the front of the lens, would you
prefer that scratch on an easily replaceable filter, or an expensive lens.
Yes, I know that good quality filters are expensive, but they would be less
expensive than the lens itself.

My lenses that have recessed front elements do not have filters. On
those I add a filter only if there is a lot of dust, moisture, etc.

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Use of UV filters
 

Bruce wrote:
"mj" wrote:
For better than 20 years I serviced both 35mm and most medium format
systems. I can say that in a small percentage of all the lenses I have
repaired (less then 20%) I have seen "protection" filters break into the
front element of the lens scratching it. Hoods generally offer better impact
protection. IMO


How much protection does a hood offer against damaging the front
element of the lens through careless cleaning?

A filter is extremely easy to clean. You can even take it off the
lens to clean it. If you scratch or damage a filter, it is quick and
relatively cheap to replace. Try doing that with the front element of
a good quality lens, and you will be faced with a very large bill.

Just dab some india ink into the scratch and put the filter back on the
lens. I have filters going well over $100. I'm not throwing them out!

[Of course you could always sell it on eBay, claiming that the
defective front element did not affect the quality of the images
produced ... funny how many lenses on eBay are thus described!]

With film, the often alleged optical degradation through using a
filter was a non-issue as long as good quality multi-coated filters
were used. However, things have changed a little with digital because
of the greater reflectivity of the digital sensor. Whether the latest
filter coatings have made this a non-issue once again is a moot point.

I've seen a scant few examples of this effect and the promotion of the
idea seems to be bread and butter of Sigma to promote their 'digital'
lenses.


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