How plastic helps take out $1000 lenses

On Wed, 06 May 2015 11:54:40 -0400, nospam
wrote:

In article , Bill W
wrote:

kit lenses are rarely the best a company makes. doesn't pentax have
swm/usm motors in non-kit lenses?

They do now, but I'm not sure how long they've had them.

it's relatively recent. wasn't it the pentax k-series that added swm
support? i don't think the *ist series (what an awful name) had it.

I'm not sure, but you're right about the name. Sigma didn't include IS
in their Pentax mount lenses, because they thought the "is" in the
name meant it was a stabilized body.

They're still
much more expensive than Sigma, and the optics generally aren't
better, at least in the lens types I've bought.

many pentax lenses were (and still are) legendary, especially the older
stuff.

unfortunately, a lot of their recent lenses are not quite as good.

anyway, as the saying goes:
fool me once, shame on you, fool me twice, shame on me.
there are much better alternatives than sigma, and from companies that
are nowhere near as sleazy.

Tamron would be the usual alternative, but it appears they've stopped
offering Pentax mounts. Some of the Samyang lenses are great, but they
don't offer anything I've needed. I do zero portrait stuff, and I
don't have use for their MF primes that get the great reviews.

nikon/canon are the two major players, so that's where the third party
lens makers put their efforts.

unfortunately, pentax doesn't have the user base anymore to justify
making yet another mount for every lens. even sony doesn't always get
third party lens support.

I'm pretty much screwed in that respect. I wouldn't get enough selling
all my Pentax stuff to make a switch much less painful. Sigma did tell
me that they intend to keep including Pentax mounts, but not on every
new lens, including the new 150-600, or 150-500, can't remember which
one.

In article , Bill W
wrote:

Tamron would be the usual alternative, but it appears they've stopped
offering Pentax mounts. Some of the Samyang lenses are great, but they
don't offer anything I've needed. I do zero portrait stuff, and I
don't have use for their MF primes that get the great reviews.

nikon/canon are the two major players, so that's where the third party
lens makers put their efforts.

unfortunately, pentax doesn't have the user base anymore to justify
making yet another mount for every lens. even sony doesn't always get
third party lens support.

I'm pretty much screwed in that respect. I wouldn't get enough selling
all my Pentax stuff to make a switch much less painful. Sigma did tell
me that they intend to keep including Pentax mounts, but not on every
new lens, including the new 150-600, or 150-500, can't remember which
one.

as i said, nikon/canon gets the love. pentax/sony do not.

i think there are even a couple of lenses that sigma doesn't make for
their *own* sigma mount.

"Bill W" wrote in message
...
On Wed, 06 May 2015 11:54:40 -0400, nospam
wrote:

In article , Bill W
wrote:

kit lenses are rarely the best a company makes. doesn't pentax have
swm/usm motors in non-kit lenses?

They do now, but I'm not sure how long they've had them.

it's relatively recent. wasn't it the pentax k-series that added swm
support? i don't think the *ist series (what an awful name) had it.

I'm not sure, but you're right about the name. Sigma didn't include IS
in their Pentax mount lenses, because they thought the "is" in the
name meant it was a stabilized body.

I don't believe that's true at all. As the Pentax DSLR line grew, Sigma
began to make lenses in that mount and most fo the model had in-camera
stablization so they didn't include it in the lens, just like the Sony
mount lenses.

They're still
much more expensive than Sigma, and the optics generally aren't
better, at least in the lens types I've bought.

many pentax lenses were (and still are) legendary, especially the
older
stuff.

unfortunately, a lot of their recent lenses are not quite as good.

anyway, as the saying goes:
fool me once, shame on you, fool me twice, shame on me.
there are much better alternatives than sigma, and from companies
that
are nowhere near as sleazy.

Tamron would be the usual alternative, but it appears they've
stopped
offering Pentax mounts. Some of the Samyang lenses are great, but
they
don't offer anything I've needed. I do zero portrait stuff, and I
don't have use for their MF primes that get the great reviews.

nikon/canon are the two major players, so that's where the third party
lens makers put their efforts.

unfortunately, pentax doesn't have the user base anymore to justify
making yet another mount for every lens. even sony doesn't always get
third party lens support.

I'm pretty much screwed in that respect. I wouldn't get enough selling
all my Pentax stuff to make a switch much less painful. Sigma did tell
me that they intend to keep including Pentax mounts, but not on every
new lens, including the new 150-600, or 150-500, can't remember which
one.

With Pentax-mount lenses, it's not a matter of Sigma or any other third
party lens maker to just change the mount. Pentax uses mechanical parts
for aperture control and that requires different parts for those lenses
than other mount lenses do. It also requires different production runs
to make them.

On Wed, 6 May 2015 16:26:52 -0400, "PAS" wrote:

"Bill W" wrote in message
.. .
On Wed, 06 May 2015 11:54:40 -0400, nospam
wrote:

In article , Bill W
wrote:

kit lenses are rarely the best a company makes. doesn't pentax have
swm/usm motors in non-kit lenses?

They do now, but I'm not sure how long they've had them.

it's relatively recent. wasn't it the pentax k-series that added swm
support? i don't think the *ist series (what an awful name) had it.

I'm not sure, but you're right about the name. Sigma didn't include IS
in their Pentax mount lenses, because they thought the "is" in the
name meant it was a stabilized body.

I don't believe that's true at all. As the Pentax DSLR line grew, Sigma
began to make lenses in that mount and most fo the model had in-camera
stablization so they didn't include it in the lens, just like the Sony
mount lenses.

Right, but the ist body did not have stabilization. When I called
Sigma to ask why they didn't include IS in a lens I wanted, they told
me that they thought the ist's were stabilized. Oddly, I do have one
of their lenses that is stabilized, one that came out well after that
conversation.

In article , PAS
wrote:


I'm pretty much screwed in that respect. I wouldn't get enough selling
all my Pentax stuff to make a switch much less painful. Sigma did tell
me that they intend to keep including Pentax mounts, but not on every
new lens, including the new 150-600, or 150-500, can't remember which
one.

With Pentax-mount lenses, it's not a matter of Sigma or any other third
party lens maker to just change the mount. Pentax uses mechanical parts
for aperture control and that requires different parts for those lenses
than other mount lenses do. It also requires different production runs
to make them.

nikon uses mechanical linkages too.

the reality is that pentax doesn't have the market share to justify
bothering making a version in every case.

as i said, sigma doesn't even bother with their own mount sometimes,
and that's even worse because it's a ripoff of canon/pentax mounts.

On 7/05/2015 9:00 a.m., nospam wrote:
In article , PAS
wrote:


I'm pretty much screwed in that respect. I wouldn't get enough selling
all my Pentax stuff to make a switch much less painful. Sigma did tell
me that they intend to keep including Pentax mounts, but not on every
new lens, including the new 150-600, or 150-500, can't remember which
one.

With Pentax-mount lenses, it's not a matter of Sigma or any other third
party lens maker to just change the mount. Pentax uses mechanical parts
for aperture control and that requires different parts for those lenses
than other mount lenses do. It also requires different production runs
to make them.

nikon uses mechanical linkages too.

Something which will be gradually phased out with new "E" (electronic
aperture) lenses. Limited to PC-E and some expensive long teles (incl
the 300 f4"E" PF) at the moment, but it's sure to migrate down the range.

the reality is that pentax doesn't have the market share to justify
bothering making a version in every case.

as i said, sigma doesn't even bother with their own mount sometimes,
and that's even worse because it's a ripoff of canon/pentax mounts.

I wonder how many of the assorted Sigma SD*** dslrs have been sold.
Enthusiasts in forums get quite vocal about them, but I can't say that I
recall ever seeing one being used in the field.
I also wonder whether Sigma killed Foveon, or vice-versa. Perhaps if
another sensor maker allied with a decent camera brand had invested
something in the foveon concept, they'd have come up with something
where the disadvantages don't so heavily outweigh the advantages.

I feel a little bit the same about Fuji "x-trans". Not that they're as
fundamentally flawed as Foveon, but the sensors don't seem to offer any
advantage over normal Bayer CFA sensors, and have lower resolution than
most basic APS-c consumer dslrs/milcs. - a situation Fuji has been in
before with their s3-5 dslr models. They got leap-frogged when
increased DR of conventional sensors in the shadow end offset (the very
real) advantages they had in highlight protection - the mainstream
makers simply adding features like Nikon's d-lighting to take advantage
of increased DR in the shadows. A case might have been able to be made
that this wasn't quite as good, but the marketplace seemed to disagree.

On Thu, 07 May 2015 13:45:50 +1200, Me wrote:

I also wonder whether Sigma killed Foveon, or vice-versa. Perhaps if
another sensor maker allied with a decent camera brand had invested
something in the foveon concept, they'd have come up with something
where the disadvantages don't so heavily outweigh the advantages.

What is the issue with those sensors? I've never paid much attention,
mainly because they seemed to be stillborn.

On 7/05/2015 2:20 p.m., Bill W wrote:
On Thu, 07 May 2015 13:45:50 +1200, Me wrote:

I also wonder whether Sigma killed Foveon, or vice-versa. Perhaps if
another sensor maker allied with a decent camera brand had invested
something in the foveon concept, they'd have come up with something
where the disadvantages don't so heavily outweigh the advantages.

What is the issue with those sensors? I've never paid much attention,
mainly because they seemed to be stillborn.

The sensor relies on shorter wavelength (ie blue) penetrating deeper
into silicon than longer wavelength (ie red) and middle wavelengths (ie
green) being absorbed in the middle. If it worked well - it would be
terrific - no quantum efficiency loss through RGB filters. It doesn't
work well, because so many photons get absorbed in the wrong layers that
a large correction is required to try and "correct" the inaccurate
colour information passed on by the sensor, that the overall number of
photons actually being used to create the image is significantly fewer
than are used even after some are blocked by the Bayer CFA in a
conventional sensor. So high ISO performance tends to be lousy, colour
accuracy tends to be lousy. Yes - they can resolve special test patterns
made up from primary colours better than Bayer CFA sensors, however
you'll be struggling to find any normal substance or subject which has
the characteristic patterns for which Foveon shows any advantage,
perhaps some woven fabrics, but not much else.
Silicon just isn't good enough to do the (colour filtration/separation)
job, or perhaps Foveon aren't good enough to best make use of the
properties of silicon. If a different material was able to be used -
some nanoparticles perhaps which would absorb some wavelengths and
generate a measurable charge, but would allow other wavelengths to pass
through to be absorbed by different nanoparticles, that would be great.
I'm not holding my breath on that breakthrough - if ever - coming from
Sigma/Foveon.

On Thu, 07 May 2015 14:50:09 +1200, Me wrote:

On 7/05/2015 2:20 p.m., Bill W wrote:
On Thu, 07 May 2015 13:45:50 +1200, Me wrote:

I also wonder whether Sigma killed Foveon, or vice-versa. Perhaps if
another sensor maker allied with a decent camera brand had invested
something in the foveon concept, they'd have come up with something
where the disadvantages don't so heavily outweigh the advantages.

What is the issue with those sensors? I've never paid much attention,
mainly because they seemed to be stillborn.

The sensor relies on shorter wavelength (ie blue) penetrating deeper
into silicon than longer wavelength (ie red) and middle wavelengths (ie
green) being absorbed in the middle. If it worked well - it would be
terrific - no quantum efficiency loss through RGB filters. It doesn't
work well, because so many photons get absorbed in the wrong layers that
a large correction is required to try and "correct" the inaccurate
colour information passed on by the sensor, that the overall number of
photons actually being used to create the image is significantly fewer
than are used even after some are blocked by the Bayer CFA in a
conventional sensor. So high ISO performance tends to be lousy, colour
accuracy tends to be lousy. Yes - they can resolve special test patterns
made up from primary colours better than Bayer CFA sensors, however
you'll be struggling to find any normal substance or subject which has
the characteristic patterns for which Foveon shows any advantage,
perhaps some woven fabrics, but not much else.
Silicon just isn't good enough to do the (colour filtration/separation)
job, or perhaps Foveon aren't good enough to best make use of the
properties of silicon. If a different material was able to be used -
some nanoparticles perhaps which would absorb some wavelengths and
generate a measurable charge, but would allow other wavelengths to pass
through to be absorbed by different nanoparticles, that would be great.
I'm not holding my breath on that breakthrough - if ever - coming from
Sigma/Foveon.
Ah - thanks for that. I knew something was holding them back, but
that does sound like something that won't be overcome anytime soon.

In article , Me
wrote:

the reality is that pentax doesn't have the market share to justify
bothering making a version in every case.

as i said, sigma doesn't even bother with their own mount sometimes,
and that's even worse because it's a ripoff of canon/pentax mounts.

I wonder how many of the assorted Sigma SD*** dslrs have been sold.

not many.

sigma enjoys less than 1% market share and loses money on every sale.

not a very good business model.

Enthusiasts in forums get quite vocal about them, but I can't say that I
recall ever seeing one being used in the field.

that's because they sell so few.

I also wonder whether Sigma killed Foveon, or vice-versa. Perhaps if
another sensor maker allied with a decent camera brand had invested
something in the foveon concept, they'd have come up with something
where the disadvantages don't so heavily outweigh the advantages.

foveon was losing money and was on the verge of bankruptcy.

since sigma had invested a lot in the sensor, they *had* to buy foveon
or they'd be stuck with cameras and no sensors. fortunately for them,
they got the company at firesale prices.

they're still throwing lots of money at the technology, but that can't
last forever. nobody can break the laws of physics.