Re: [Leica] Summilux-m 35mm f1.4 asph & uv filter

[Jim Brick <jim@brick.org>]

You can probably answer your own question. In order to realize the answer, you
really need to think about the situation. Not just have the answer blurted
out.
If you get stuck, just ask and I'll gladly help.

1. Do you know why Leica (and all other major lens manufacturers) has spent an
enormous amount of research time and money, developing and purchasing very
expensive, hi-tech, very sophisticated, multicoating apparatus, to multicoat
the FRONT element of your exquisite lens? 

2. Do you know what the purpose of this coating is? 

3. Other than optically transparent glue, do you know what other chemical is
with the glue between the lens elements? 

4. How much does a UV filter cost? 

5. How much did your lens cost? 

6. What does a UV filter do for you?

7. And last, but not least, why do you have a UV filter on your lens? 



At 09:31 PM 1/25/98 -0500, you wrote: 
>
> I am using the 35mm summilux-m f1.4 asph with the Leica uv (13004) filter.
> Someone told me
> that I was loosing the sharpnes of the lens with that filter. Any comments
> from users?
> I always beleived good quality uv filter did not altered the quality of the
> lens.



Answers:

1. & 2. So that when the rays of light, emanating from the subject, (whether
the sun, moon, or people) and kiss the front element of your lens, they will
pass right on in, without reflecting off of the surfaces of the elements
causing flare. Flare can be simply a slight reduction on contrast, sometimes
un-noticed. But there. Sometimes it's like white wash over the entire image.
Producing unusable photographs.

3. A UV inhibitor so that a UV filter is not needed.

4. much less that $100.

5. More than $1000

6. Reduces your $1000+ lens to the quality of your $100- filter. The front
surface of a filter WILL NOT INHIBIT FLARE. The front element of your
expensive
lens WILL INHIBIT FLARE. You paid dearly for this anti-flair coating. See 1. &
2.

7. Use a lens cap. That's what it's for.

Jim

ps... the LUG old timers know I take a hard line with filters. I personally
use
filters a lot. BUT... I use a filter only for a particular purpose. Polarizer,
warming, ND Grad, color grad. There must be a useful purpose for me to render
my expensive front element useless. When you have a filter on your lens. DO
NOT
let a single ray of direct sunlight hit the filter. You will have some
level of
flare. Guaranteed. M cameras work best with no filter because, while street or
other hand held shooting, you cannot guarantee that stray bright light will
not
hit the filter.