Tamron Lens

"Alfred Molon" wrote:
wrote:
Alfred Molon wrote:

This is a scan of a slide taken with an SLR and the Tamron lens (scanned
with a Nikon LS50 4000 dpi scanner). Very blurry and lots of chromatic
aberrations.

I don't know. Reduced to 800*540 with Nearest Neighbor, and given 155%
USM @ 0.5px, it looks pretty sharp.

Yes, if you reduce the resolution and unsharp mask it, it looks sharp.
But at 800x540 we are not even at the level of a 1MP digital camera
(resolutionwise) - and it has always been stated that film has as much
resolution as an 8MP digital camera.

It's really hard to get anywhere close to the theoretical resolution of film
from film. Really hard. Prime lens, tripod, slow film. Hand held, ISO 200 or
faster film, or a cheap zoom lens and you'll rarely be even close.

David J. Littleboy
Tokyo, Japan

On Thu, 19 Aug 2004 03:25:08 GMT, "Steve" wrote:

I have seen that the Canon 28-135 is an good lens accourding to some for the
Canon 10D, what is wrong with the Tamron AF 28-300mm Ultra Zoom as a all
around lens for most shooting. Is the distortion really that bad for the
price or do I need to carry around three lenses to do the same range.
What is the point, are the others really that much better
such as the 28-135 which allows dust into it worth the extra cost and is the
USMs much faster for focus.

If you bought a DSLR, with the feature of a removable lens so that you
can use the best lens for the particular job, and then seek to replace
that feature with an "all in one" lens, you've just wasted (IMO of
course) a good portion of the money you spent on the DSLR.

I typically run around with three lenses in my bag; the 28-135 IS USM,
a fast 50mm, and an el-cheepo 70-300mm (I got lucky with the 70-300
and got one with very good behavior).

For special occasions I also throw a 19-35mm into the mix.

While I sometimes think it would be nice to just have one piece of
equipment to cover the whole range, I just haven't seen an "all in
one" lens that beats the individual lenses for performance.


Drifter
"I've been here, I've been there..."

On Thu, 19 Aug 2004 03:25:08 GMT, "Steve" wrote:

I have seen that the Canon 28-135 is an good lens accourding to some for the
Canon 10D, what is wrong with the Tamron AF 28-300mm Ultra Zoom as a all
around lens for most shooting. Is the distortion really that bad for the
price or do I need to carry around three lenses to do the same range.
What is the point, are the others really that much better
such as the 28-135 which allows dust into it worth the extra cost and is the
USMs much faster for focus.

If you bought a DSLR, with the feature of a removable lens so that you
can use the best lens for the particular job, and then seek to replace
that feature with an "all in one" lens, you've just wasted (IMO of
course) a good portion of the money you spent on the DSLR.

I typically run around with three lenses in my bag; the 28-135 IS USM,
a fast 50mm, and an el-cheepo 70-300mm (I got lucky with the 70-300
and got one with very good behavior).

For special occasions I also throw a 19-35mm into the mix.

While I sometimes think it would be nice to just have one piece of
equipment to cover the whole range, I just haven't seen an "all in
one" lens that beats the individual lenses for performance.


Drifter
"I've been here, I've been there..."

On Thu, 19 Aug 2004 19:00:03 GMT, "Steve" wrote:

I would have thought by now with the improvements in lasers and the computer
filed that the science of lens making would have jumped ahead in the
development.
What I gather is the older lenses from 20 plus years to now has not
changed much. Either the cost is very high for low distortion,and tack sharp
pictures. Why is it hard now to develop a great lens with a 28-300 range
with much better results with a lower price. Now with modeling programs and
Lasers the distortion should have came down and development much faster.

Unfortunately it's not just design and the behavior of light, it's
also chemistry, physics, and the art of glassmaking. On the other
hand I did recently read a very interesting article on "liquid lenses"
(I wish I could find the link). Apparently the concept is to use a
suspended oil film as the lens. It adds a whole new dimension in lens
performance, has no chromatic aberration, and is self cleaning.
Unfortunately it is also extremely fragile and the slightest wind pops
the oil film so you have to restart it. Essentially useless in it's
present form, but maybe an indicator of things to come?


Drifter
"I've been here, I've been there..."

On Thu, 19 Aug 2004 19:00:03 GMT, "Steve" wrote:

I would have thought by now with the improvements in lasers and the computer
filed that the science of lens making would have jumped ahead in the
development.
What I gather is the older lenses from 20 plus years to now has not
changed much. Either the cost is very high for low distortion,and tack sharp
pictures. Why is it hard now to develop a great lens with a 28-300 range
with much better results with a lower price. Now with modeling programs and
Lasers the distortion should have came down and development much faster.

Unfortunately it's not just design and the behavior of light, it's
also chemistry, physics, and the art of glassmaking. On the other
hand I did recently read a very interesting article on "liquid lenses"
(I wish I could find the link). Apparently the concept is to use a
suspended oil film as the lens. It adds a whole new dimension in lens
performance, has no chromatic aberration, and is self cleaning.
Unfortunately it is also extremely fragile and the slightest wind pops
the oil film so you have to restart it. Essentially useless in it's
present form, but maybe an indicator of things to come?


Drifter
"I've been here, I've been there..."