A couple of really small scratches only cause a problem if you look for
them! If you don't look, I can assure you that you won't notice them.
The cloudiness might be an oil mist or might be fungus. From your
description, I suspect the former, which might be easier to clean than the
latter - but it isn't economically sensible to do so. I expect the lens has
reduced contrast as a result of the cloudiness.
When you are looking into the sun, you probably put your hand up to shade
your eyes from the sun - it helps you to see! Same with lenses, but hoods
are easier to use than your hands.
UV filters do just that, they filter UltraViolet light which is invisible to
the eye, but to which colour film is sensitive. In snow scenes or at high
altitude, there is a high UV element to daylight, which would result in an
excessively blue image on film. They have no other effect on the image, and
can thus be left on the lens as a protector. Others favour Skylight
filters, which are pale pink, and thus have a more marked warming effect on
the image.
--
Piers
-----Original Message-----
From: olympus-owner@xxxxxxxxxx [mailto:olympus-owner@xxxxxxxxxx] On Behalf
Of Rob Smith
Sent: 21 January 2005 09:04
To: 'olympus@xxxxxxxxxx'
Subject: [OM] Learning about lenses
Thankyou Moose, I read your note on using later lenses.
Do Zuiko Serial numbers run sequentially? so a larger number would be a
later lens?
I have a 50mm f1.8 which is now junk but has thrown up a couple of questions
I would like to ask:
If I look very carfully at the front element and catch a very bright light
just right I can see a couple of realy small scratches. Without carefull
looking you would not see them.
Would these cause problems?
If I also look very, very carefully at an angle to the rear element under
very bright light I can see what looks like very very fine yellowy
condensation. It is not condensation but that is my best description. You
cannot see it if you look at it straight on.
The lens also looks slightly cloudy if you shine a bright light through from
the rear and look at the front from one side. My other 50mm f1.8 does not do
this.
Any diagnosis?
Is it a good idea to get hoods for each of my lenses?
Does this reduce stray light entering from outside the lens 'cone' and does
this help with image quality?
I wish to get filters for all my lenses to protect the front elements.
What does a UV filter do?
Should I just get plain filters just for lens protection?
Rob
-----Original Message-----
From: Moose [mailto:olymoose@xxxxxxxxxxxxxxx]
Sent: 21 January 2005 08:27
To: olympus@xxxxxxxxxx
Subject: [OM] Re: OM1n and Lenses
robert smith wrote:
>I have now re-subscribed from home as I was getting no work done at work.
>Previously subscribed as robsmith@xxxxxxxxxxxx
>
>It seems I need to invest a bit to get a reasonable kit together to
>cover
most things I would like to photograph.
>I think this is the main reason why I was a bit dissapointed with my OM10.
>I often had a great subject and lighting but only had the two lenses
>which
never brought out what I could see.
>
>Getting my OM1n into good shape is high on my list.
>I will also get some more Zuiko lenses.
>This is where I would like some guidance.
>
Some Zuikos were better than others when new. All OM zuikos are now rather
old. Some of them have had tough lives and/or difficult experiences.
Generalities about indivudual designs such as found here, in Gary's lens
tests, etc. can be a big help. One also needs to try to find good examples.
If, as you say above, a lens "never brought out what I could see", that may
be a characteristic of the particular example, rather than that model.
I know lots of folks look for bargains in lenses which are cosmetically not
too good looking, but have perfect looking glass. I think that's a fair way
to go bargain hunting, but one should be aware that signs of rough handling
may also increase the risk of internal misalignment or other maladies that
can only be found through testing.
>Zooms
>Hopefully I am buying a 35-70mm f3.6
>
An excellent model. I personally prefer the 3.5-4.5 in that focal length
range for its diminutive size and low weight. If I go bigger and heavier, I
prefer 35-105 or longer.
>I have a 100-200mm f5 which is quite dusty inside and a bit rough and
slightly loose on its zoom slide but seems to work ok, but not economically
viable to have it overhauled.
>It may be better for me to get another zoom from 70mm up. Any views on
this?
>
The great, common bargain in this range is the Tamron SP 60-300/3.8-5.4.
A good one will be sharp at all focal lengths and all but the smallest
apertures and it has a really excellent macro capability. The 50-250 Zuiko
is apparently a very good lens, but too many of them have an unrepairable
clouding of a rearish element. For speed, the Tamron SP
80-200/2.8 is one of the great MF lenses of all time and the Tokina AT-X is
a close second. Oly never made anything in this size/speed range.
>Prime Lenses
>I have a very tidy 28mm f2.8
>I am getting a 50mm f1.4 to replace my f1.8 with a tiny flake chipped
>off
one of the lenses deep inside.
>
There were at least 3 different 50/1.4 and 5 50/1.8 designs over the years.
If you were to switch from a late 50/1.8 to an early 1.4, you would find a
considerable loss of image quality. Look at Gary's tests and the eSIF for
inof on performance and how to tell which is which.
>Is a 135mm f2.8 a good lens?
>
The Zuiko is an excellent design.
>I have sat peering through my 100-200 set at about 135 to see what
situations I might use such a lens.
>I have concluded that it would be within my price range and a good lens
>to
get and that I should stop trying to take pictures which need the longer
more expensive lenses.
>
Maybe. I have a hard time keeping from taking pics of things too small of
far away and then wondering what I was thinking when the film comes back.
135 mm is a length some people love and others don't like. Focal length
preferences are a highly individual thing
>I can always get a longer lens later.
>Presumably the 135 f2.8 be far brighter and easier to focus than the
100-200 f5 which I struggle with?
>
Oh yes!
Moose
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