Optics

Are the lenses always fundamentally of better quality in a Canon or Nikon
dlsr than in a same brands bridge or compact camera?
I have in mind the Canon 400d/Nikon d40 compared lens-wise to say a Canon S5
IS.

JB

On Jul 1, 9:09 am, "Jackson Bryan" wrote:
Are the lenses always fundamentally of better quality in a Canon or Nikon
dlsr than in a same brands bridge or compact camera?
I have in mind the Canon 400d/Nikon d40 compared lens-wise to say a Canon S5
IS.

JB

"Fundamentally" is a somewhat ambiguous term. There is nothing
theoretical that would make a lense on a compact P&S camera of lessor
quality than an SLR. Of course, there is something to the old saying
that you get what you pay for. And consider that many P&S cameras
cost about the same as what just a lens for an SLR costs.

Also, one has to define what aspects of quality. There are two main
considerations, design and "workmanship" Lenses of the same focal
length(s) and aperture can vary on how well they perform. "Cheaper"
lenses may be less well corrected, and for zoom lenses the image
quality may not be the same at each focal length. Same thing with
focusing distance. Some lenses work very well at say, infinity object
distance but poor with closer objects even when they can focus on that
object. Others are of good image quality from infinity to their
closest focal distance. One factor is the number of elements,
especially for zoom lenses- another is the glasses used.

Then there is the issue of workmanship. Two different shops can
produce the same exact design and have significant differences in
quality. Two main workmanship factors are important. First is
tolerancing. That is, how close to the design-specified values are
the curvature of each surface, thickness of each element, and
alignment of the surfaces, i.e., minimal tilt.

The second big factor is surface finish- that is, how well they are
polished to eliminate scratches and pits.

While there have been tremendous advances in mass producing optical
lenses in the past quarter century, one still must believe that the
better the quality of the lenses, the higher the cost.

On Jul 1, 10:09 am, "Jackson Bryan" wrote:
Are the lenses always fundamentally of better quality in a Canon or Nikon
dlsr than in a same brands bridge or compact camera?
I have in mind the Canon 400d/Nikon d40 compared lens-wise to say a Canon S5
IS.

JB

There have been some P&S cameras with outstanding lenses that if
duplicated on a DSLR would be considered pro grade. But Canon never
made any. Olympus, Sony and Nikon did. However, if the lens is good
and matched to a second-rate sensor (like the ubiquitous 1/2.5" that
has found its way into most cheap or long zoom P&Ss today) then it
really doesn't matter if the lens it top flight. On the few P&Ss
manufactured with good sensors (Fuji's 1/1.7" or the older and larger
2/3" sensors used in the Olympus C-8080 or Nikon 8800) good lenses do
matter and do make a major difference.
As to your statement, it would be more accurate to say that you rarely
see aberrations as bad on DSLR lenses (even cheap kit lenses) that you
see on P&S lenses. Chromatic aberration is a main one. You often see
horrible CA when a P&S camera is used with it's lens wide open, or
even closed down somewhat.

Jackson Bryan wrote:
Are the lenses always fundamentally of better quality in a Canon or
Nikon dlsr than in a same brands bridge or compact camera?
I have in mind the Canon 400d/Nikon d40 compared lens-wise to say a
Canon S5 IS.

JB

Exactly what do you mean by "better?"

To me the best lens is any one that does the job.

While the people posting here are exceptions in many ways, few people
are ever going to experience any difference in results using the finest
professional quality super expensive lens and the far cheaper lens on a good
P&S camera. The result limitation is more often the user than the lens -
camera.

I will be among the first to say that I am the limiting factor with my
equipment. Give my equipment to a really fine talented photographer, and
they are going to get better results. Give me an unlimited budget and let
me buy the best money has to offer and I may have results very slightly
better than I get now, but it will be no where close to what a really fine
photographer will do with my equipment.

Good photographers tend to buy good equipment, but don't confuse the
true source of the quality. It is talent, training and work that makes the
real difference.


--
Joseph Meehan

Dia 's Muire duit

On Sun, 01 Jul 2007 15:09:38 +0100, Jackson Bryan wrote:

Are the lenses always fundamentally of better quality in a Canon or Nikon
dlsr than in a same brands bridge or compact camera?
I have in mind the Canon 400d/Nikon d40 compared lens-wise to say a Canon S5
IS.

JB

No - you can get crappy lenses for anything.

On Jul 1, 1:31 pm, "Joseph Meehan" wrote:
Jackson Bryan wrote:
Are the lenses always fundamentally of better quality in a Canon or
Nikon dlsr than in a same brands bridge or compact camera?
I have in mind the Canon 400d/Nikon d40 compared lens-wise to say a
Canon S5 IS.

JB

Exactly what do you mean by "better?"

To me the best lens is any one that does the job.

It's already getting interesting with 10 megapixels. Wait till there
are 20 on a FF sensor and then see what lenses "do the job."

Rich wrote:
[]
It's already getting interesting with 10 megapixels. Wait till there
are 20 on a FF sensor and then see what lenses "do the job."

... and with smaller pixels you may need larger aperture lenses to keep the
same signal/noise value, and those larger aperture lenses may produce a
large image spot (PSF), and hence the whole trade-offs change. Leading to
the question: is there an optimum number of pixels for full-frame and
smaller-frame cameras?

David

Hi.

On Jul 1, 9:09 am, Don Stauffer in Minnesota
wrote:

There is nothing theoretical that would make a lense on a compact P&S camera of lessor quality than an SLR (excerpt)

While there have been tremendous advances in mass producing optical lenses in the past quarter century (excerpt)

Thank you for your thoughtful and well written reply to JB.

I use a Canon 350XT for most work. Because of it's size - I have
purchased an Olympus 740 ultracompact p&s for field trips. etc.

I was shocked yesterday while shooting at a swim pool with the p&s
just how good and useful it is. Distances shot were between ~30 - 70
feet. I expected some (many) of the pics to be blurred because I was
hand holding the camera. What a surprise that most of the shots were
quite acceptable (to me). People are much more relaxed when not posing
for a picture.

The 740 camera has 5x optical zoom and 5.8 digital zoom (total ~ 28x)
and IS. I know the arguments for not using digital zoom but I must say
I found the cropping effects and quality of longer shots surprised
me.

This will be a most useful camera (for me) to "carry" on the hiking
trails and other outdoor activities. A delightful surprise.

Best,

Conrad

PS I did get carried away and shot a fire scar on a nearby (~3-5
miles) cinder cone volcano that came out reasonably good. Previously I
had tried this shot with my 350XT using 300mm lens and 2x tele/
extender. Let's leave it at I was pleasantly surprised at what the p&s
produced.

On Jul 2, 1:05 am, "David J Taylor" ensor and then see what lenses "do
the job."

.. and with smaller pixels you may need larger aperture lenses to keep the
same signal/noise value, and those larger aperture lenses may produce a
large image spot (PSF), and hence the whole trade-offs change. Leading to
the question: is there an optimum number of pixels for full-frame and
smaller-frame cameras?

David

That is a very interesting question. Many years ago I worked on a
project concerning CCD cameras for aerial reconnaisscence. It
certainly seemed that a trade study would identify such an optimum
size, but we did not win the contract so did not run the trade study.
Now that I am retired and have spare time, maybe I should see if I can
do it now.

On Jul 2, 2:05 am, "David J Taylor" -this-
part.nor-this-bit.co.uk wrote:
Rich wrote:

[]

It's already getting interesting with 10 megapixels. Wait till there
are 20 on a FF sensor and then see what lenses "do the job."

.. and with smaller pixels you may need larger aperture lenses to keep the
same signal/noise value, and those larger aperture lenses may produce a
large image spot (PSF), and hence the whole trade-offs change. Leading to
the question: is there an optimum number of pixels for full-frame and
smaller-frame cameras?

David

Depends on what you want. If your goal is strictly detail resolution
and you don't care about things like DR, or tonality, etc, the number
of pixels would differ from someone looking for all three attributes.
Look at the 10 megapixel 1.5s versus the 6 megapixel. Nikon's D40x
and D40 are a good case in point, a good way to compare results.