What makes the tiny digicams lenses so good?

Thirty or 40 years ago I used to have a Pentax Spotmatic (printing black
and white in my own darkroom) and graduated onto several other SLRs from
there. I used labs for color. My pictures were never printed beyond 10
x 8 and to be honest you might call the majority of my photos as "high
quality family pictures".

After years of SLRs and some higher quality 35mm compacts, I didn't
really use my cameras for about 10 or 15 years.

-----

Then recently I got to use one of the modern digital compacts. It was a
Canon Powershot SD450. (UK: Canon IXUS 55.) 5 MP. A 6 element lens
in 5 groups. Max aperture of f/2.8 at full wide angle (less on
telephoto)

My! Oh my! The results are really very good. I look at the tiny weeny
little microscopic lens and when I see what it can do then I'm very
impressed. Reviews suggest it I could get a really very decent 10 x 8
color print from this.

-----

Of course contrast, color, vignetting, fringing, distortion may not be
100% but they are nevertheless more than adequate for a lot of photos.

QUESTION:
How does this sort of compact digital camera lens (or even those from
the slightly better compacts digicams) compare to those old lenses
without going to the extreme:

Takumar or Super Takumar (42mm thread) on the old Spotmatic?
http://tinyurl.com/8clur

the FD lenses on the slightly later Canon AE-1 (bayonet).
http://www.camerahobby.com/Review-AE1.html

the Olympus Zuikos lenses (bayonet) found on the almost as old Olympus
OM-1? http://tinyurl.com/2kwss

Don W wrote:
> Thirty or 40 years ago I used to have a Pentax Spotmatic (printing
> black and white in my own darkroom) and graduated onto several other
> SLRs from there. I used labs for color. My pictures were never
> printed beyond 10 x 8 and to be honest you might call the majority of
> my photos as "high quality family pictures".
>
> After years of SLRs and some higher quality 35mm compacts, I didn't
> really use my cameras for about 10 or 15 years.
>
> -----
>
> Then recently I got to use one of the modern digital compacts. It
> was a Canon Powershot SD450. (UK: Canon IXUS 55.) 5 MP. A 6
> element lens in 5 groups. Max aperture of f/2.8 at full wide angle
> (less on telephoto)
>
> My! Oh my! The results are really very good. I look at the tiny
> weeny little microscopic lens and when I see what it can do then I'm
> very impressed. Reviews suggest it I could get a really very decent
> 10 x 8 color print from this.
>
> -----
>
> Of course contrast, color, vignetting, fringing, distortion may not be
> 100% but they are nevertheless more than adequate for a lot of photos.
>
> QUESTION:
> How does this sort of compact digital camera lens (or even those from
> the slightly better compacts digicams) compare to those old lenses
> without going to the extreme:
>
> Takumar or Super Takumar (42mm thread) on the old Spotmatic?
> http://tinyurl.com/8clur
>
> the FD lenses on the slightly later Canon AE-1 (bayonet).
> http://www.camerahobby.com/Review-AE1.html
>
> the Olympus Zuikos lenses (bayonet) found on the almost as old Olympus
> OM-1? http://tinyurl.com/2kwss

There are many factors, not just the lens, that go into image quality.

Since you are talking about different formats (size of film - sensor) it
is really difficult to compare lenses.

Small lenses are easier to make well.

Lens design has improved over the years due to computer designs, better
glass etc.

Post exposure processing has been a plus in many ways (also a scourge in
others).

If you had a full size 35mm digital SLR you would have a better
opportunity to compare apples to apples and I believe you would find that
apples are apples. The lenses are not all that different. We still have
good ones and some not so good and a few great.

--
Joseph Meehan

Dia duit

Don W wrote:
[]
> QUESTION:
> How does this sort of compact digital camera lens (or even those from
> the slightly better compacts digicams) compare to those old lenses
> without going to the extreme:

One reason is that they are no longer required to fit the SLR format, with
its mirror making the lens back-focal length requirement much greater.
Design and manufacture have, of course, improved over the years as well.

David

"David J Taylor" <david-taylor@blueyonder.co.not-this-bit.nor-this-part.uk>
wrote:
> Don W wrote:
> []
>> QUESTION:
>> How does this sort of compact digital camera lens (or even those from
>> the slightly better compacts digicams) compare to those old lenses
>> without going to the extreme:
>
> One reason is that they are no longer required to fit the SLR format, with
> its mirror making the lens back-focal length requirement much greater.

That's largely only an issue for superwides; since there aren't any wides in
the P&S world that isn't a significant point.

One point to note, though, is that as the pixel counts have been going up,
the lenses have been getting slower. It's always easier to provide good
performance in a lens if it's slower.

My bet, though, is that any of the lenses the OP mentioned would cough up
great images if mounted on a 5D and shot at f/8; there are several people
claiming certain of the Olympus OM-1 series lenses are better than current
Canon lenses on the 5D.

David J. Littleboy
Tokyo, Japan

David J. Littleboy wrote:
> "David J Taylor"
[]
>> One reason is that they are no longer required to fit the SLR
>> format, with its mirror making the lens back-focal length
>> requirement much greater.
>
> That's largely only an issue for superwides; since there aren't any
> wides in the P&S world that isn't a significant point.

But it's the whole thing about having to fit into last century's format!
Give the optical designer more freedom and they can make better lenses
(with everything else equal). Plus (as you cropped) the better design and
manufacturing techniques today. Another point is that these are fixed
lenses, designed specifically to suit the sensor used.

BTW: there are now quite a large number of non-SLR cameras with 23 - 28mm
lenses.

David

Don W wrote:
>
> QUESTION:
> How does this sort of compact digital camera lens (or even those from
> the slightly better compacts digicams) compare to those old lenses
> without going to the extreme:


One of the things that makes some lenses on smaller, cheaper cameras
work so well is that they have a smaller aperture (higher min. f/#). It
is always easier to design and build a lens of smaller aperture.
Lenses of larger aperture (lower f/#) are more complex even stopped
down.

Both the higher f/# and the shorter focal length gives you some
additional depth of field. Design techniques and fab techniques have
advanced in last two decades.


Note that the smaller aperture is common even on compact 35mm cams, not
just digitals.

Joseph and Don,

I don't mean to hijack this thread, but it might illicit some educated
responses from camera afficionados out there like you.

My Kodak DX3600 is now about five years old. The resolution of 2.2mp
has always been adequate, but the quality has never been so good. It's
now playing up and I anticipate it will die soon.

Upon replacing it, I'd like to spend a bit to give me something that I
can set up in home with some decent lighting to take nice family
portraits to send abroad to the grandfolks. I've seen photos on mom's
Panasonic camera that look like professional studio photographs when
the lighting and backgrounds were just right by coincidence (mine has
never fluked it that nice).

Let's say £300 was my budget (for divorce's sake). Is there a range of
models in the UK that would produce studio-worthy photos that will
satisfy a trained eye such as your own? Should I concentrate on what
they're calling the "prosumer" quality range and spend a bit more?

"David J Taylor" <david-taylor@blueyonder.co.not-this-bit.nor-this-part.uk>
wrote:
> David J. Littleboy wrote:
>> "David J Taylor"
> []
>>> One reason is that they are no longer required to fit the SLR
>>> format, with its mirror making the lens back-focal length
>>> requirement much greater.
>>
>> That's largely only an issue for superwides; since there aren't any
>> wides in the P&S world that isn't a significant point.
>
> But it's the whole thing about having to fit into last century's format!
> Give the optical designer more freedom and they can make better lenses
> (with everything else equal).

Well, maybe. But they can't use it because if they get too close to the
sensor, then the angle of incidence really will be a problem (normally, this
complaint about digital is FUD because the dSLR lenses are all retrofocus
(doh!), but it will impose about the same restriction on lens design as the
mirror does).

> Plus (as you cropped) the better design and manufacturing techniques
> today. Another point is that these are fixed lenses, designed
> specifically to suit the sensor used.

The last point is valid. But in terms of lines per height of resolution, the
old Pentax lenses will cough up more than the P&S lenses. I don't have any
such older 35mm lenses lying around, but the 35mm f/3.5 wide (medium-wide:
22mm equiv, but that's all you get in 645) for the Mamiya 645 is razor sharp
on the 5D. And this particular lens has a pretty poor reputation for
sharpness in the MF world. (Although it's not all that old a design,
probably early 1980s or so, I'd guess.)

> BTW: there are now quite a large number of non-SLR cameras with 23 - 28mm
> lenses.

That's pretty wimpy (and 24mm is still seriously rare). Both my dSLRs have
17mm equivalent lenses, and there's the Sigma 12-24 for folks who want to
have real fun.

David J. Littleboy
Tokyo, Japan

"Don W" <mail@mail.invalid> wrote in message
news:Xns985083882E70A74C1H4@127.0.0.1...
>
> QUESTION:
> How does this sort of compact digital camera lens (or even those from
> the slightly better compacts digicams) compare to those old lenses
> without going to the extreme:
>
>

It is as bit more complicated comparing digitsl to film, because on digital
the lens is not the only factor that determines the quality of the image.

I started in 35mm in 1973, with a Spotmatic IIa, which I still have, along
with another dozen or so bodies. In my case, I did not want to abandon my
familiar film gear, so I went with a film scanner, and I am quite content
with that arrangement. My requirements are modest, and I shoot only a roll
per week, if that.

I have had a 2.3MP digicam since 2000. It was prosumer when it was
released, and I have always been quite pleased with its results.
Nine-element, all glass lens. Remote control (great as a substitute for a
cable release when camera is on a tripod). And I always have my film gear
when I require higher resolution images.

The film scanner has, in a sense, turned all of my film cameras into digital
cameras. Since I don't have large expenditures for film and processing,
this setup works well for me.

If you still have your Spotmatics, and if you are the lower-volume shooter
that your post suggests, you too might want to consider trying a film
scanner, rather than starting over with digital bodies and their lenses, and
paying a fortune to replicate what you already have in the film domain.
This approach is probably unsuitable for people that shoot lots of images.

I rarely see reviews of lenses for digital cameras, and current software
like PSP or PS can correct for things like pinsuchion and barrel distortion,
digital noise reduction, chromatic aberration ("purple fringing"), and
perspective correction ("falling buildings"). It can also increase or
decrease sharpening, allowing you to mimic characteristics of specific
lenses. So the lens itself is not longer as critical a factor as it was
back in the days when shooting transparencies--when it was just the lens and
the film, with no intermediate influences.

My sense is that it is easier to use less-than-stellar lenses with digital
photography, since the images can be tweaked during the editing stage. It
may take additional time to tweak the images, a problem for professionals
for whom time is money, but we amateurs have a different set of requirements
than pros do.

For family photos of 8 x 10 or smaller, your choices are broad. Most
digicams are perfectly well-suited to that type of photography. I would say
that your ability to exploit the features of your editing software is
probably more important than your choice of camera, for such shots.

Digital P&S cameras are becoming more like commodities. Manufacturers are
struggling to define niches that separate their products from the rest of
the pack, but any feature of value can be easily mimiced by other
manufacturers within 6 months, when the latest updated models come out. For
my part, I've stopped trying to stay on top of the latest developments--my
film cameras do exactly whet I want them to do, I already have lots of gear,
and the film scanner enables me to take advantage of the one feature of
digital imaging that means the most to ME: that of being able to have a
digital darkroom where I can edit (and, hopefully, improve) my images prior
to printing them. The method of capture is of no importance at all.






Takumar or Super Takumar (42mm thread) on the old Spotmatic?
> http://tinyurl.com/8clur
>
> the FD lenses on the slightly later Canon AE-1 (bayonet).
> http://www.camerahobby.com/Review-AE1.html
>
> the Olympus Zuikos lenses (bayonet) found on the almost as old Olympus
> OM-1? http://tinyurl.com/2kwss
>

David J. Littleboy wrote:
> "David J Taylor"
[]
>> Plus (as you cropped) the better design and manufacturing techniques
>> today. Another point is that these are fixed lenses, designed
>> specifically to suit the sensor used.
>
> The last point is valid. But in terms of lines per height of
> resolution, the old Pentax lenses will cough up more than the P&S
> lenses. I don't have any such older 35mm lenses lying around, but the
> 35mm f/3.5 wide (medium-wide: 22mm equiv, but that's all you get in
> 645) for the Mamiya 645 is razor sharp on the 5D. And this particular
> lens has a pretty poor reputation for sharpness in the MF world.
> (Although it's not all that old a design, probably early 1980s or so,
> I'd guess.)
>> BTW: there are now quite a large number of non-SLR cameras with 23 -
>> 28mm lenses.
>
> That's pretty wimpy (and 24mm is still seriously rare). Both my dSLRs
> have 17mm equivalent lenses, and there's the Sigma 12-24 for folks
> who want to have real fun.

Accepted that what I would call ultra-wides are not available in non-SLR
cameras, although the correct use of such lenses takes a lot of care.

With digital, the need for the lens MTF changes. No longer do you want a
long tail of ever decreasing MTF, but as high an MTF as you can get up to
the Nyquist frequency (i.e. half the sampling rate), and then no more.
I've not been involved in optical design enough to know whether of not
it's easier to try and get that sort of MTF curve rather than another, but
I suspect that being allowed a wider PSF (which this seems to imply) might
also ease the design of lenses for strictly digital cameras (non SLR
cameras where the sensor resolution is fixed).

David