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I'm back with more silly / newbie questions...

In the 24 x 36 mm world, a normal lens is 50mm, normal because it offers the
same angle of vision as the human eye. Now, this might be an error, my
understanding is that at the equivalent quality, a normal lens is cheaper to
make than either a wide angle and/or a telephoto lens. At the same time,
it is possible to make normal lenses faster than any other type of lenses.

My assumption here is because with the normal lenses you don't have to bend
the light at weird angles the way it's done with wide an tele lenses. True /
false ?

Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
is 33mm. Right ?

So, are we going to see cheap 33 mm lens, and faster than what we see
today ?


Thanks.

wrote:
> I'm back with more silly / newbie questions...
>
> In the 24 x 36 mm world, a normal lens is 50mm, normal because it
> offers the same angle of vision as the human eye. Now, this might be
> an error, my understanding is that at the equivalent quality, a
> normal lens is cheaper to make than either a wide angle and/or a
> telephoto lens. At the same time,
> it is possible to make normal lenses faster than any other type of
> lenses.
>
> My assumption here is because with the normal lenses you don't have
> to bend the light at weird angles the way it's done with wide an tele
> lenses. True / false ?
>
> Now here is the real question. With the 15 x 23 mm (aps-c) sensors,
> normal is 33mm. Right ?
>
> So, are we going to see cheap 33 mm lens, and faster than what we see
> today ?
>
>
> Thanks.

No. Nearly all lenses today for digital cameras are zooms. That is
what the public wants and buys. You may start to find prime single focal
length lenses in the normal lens for digitals, and some faster, but chances
are the price will be more because the volume will be much less. The real
reason that the "normal" lenses were cheap was because they made so many of
them.

--
Joseph Meehan

Dia duit

<> writes:
> Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
> is 33mm. Right ?
>
> So, are we going to see cheap 33 mm lens, and faster than what we see
> today ?

I think it's difficult because the lens mount to film plane distance
is still the same as with a full frame SLR. So the 33mm lens has to
be built something like a full frame SLR wideangle and not like a
normal lens. I'd also say the absence of a 33mm-ish macro lens is
even more annoying than the situation with normal lenses. There are
good 35/2 and 35/1.4 lenses available if you want to pay for them.
But there's no good flat-field macro lens in that focal length.

IMO, these APS-C DSLR's using 35mm SLR lenses are something of a
stopgap because full frame sensors are still quite expensive. But I
think that will improve over the next year or two. After rebates an
EOS-5D is just a little over $2K, which is not much over what the
Nikon D100 (maybe the first more-or-less consumer DSLR) cost when it
came out.

Remember that Nikon's early DSLR's, the E2 and E3, cost over $10K each
and used 2/3", 1.3 megapixel sensors or thereabouts. I hope Nikon
will release some full frame models at PMA 2007, initially including a
D300 at today's D200 price level. Once there is competition for the
5D, these cameras should soon reach the D80 price level. Then you'll
be able to use your 50mm normal and macro lenses.

wrote:
> I'm back with more silly / newbie questions...
>
> In the 24 x 36 mm world, a normal lens is 50mm, normal because it offers the
> same angle of vision as the human eye. Now, this might be an error, my
> understanding is that at the equivalent quality, a normal lens is cheaper to
> make than either a wide angle and/or a telephoto lens. At the same time,
> it is possible to make normal lenses faster than any other type of lenses.
>
> My assumption here is because with the normal lenses you don't have to bend
> the light at weird angles the way it's done with wide an tele lenses. True /
> false ?
Sort of, less bending then a wide angle lens and smaller elements then
a telephoto lens. There is a sweet spot when lenses are the cheapest
to make and still be fast and that would seem to be right around 50mm
for a FF camera.

For those how have not had the joy of trying to design a wide angle
lens you can't make one without some pretty short radius surfaces and
this dictates some pretty tight tolerances in alignment between the
elements. You also need more elements for a wide angle lens.

> Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
> is 33mm. Right ?
>
> So, are we going to see cheap 33 mm lens, and faster than what we see
> today ?
Well getting any lens faster then about 1.2 if pretty hard no matter
how short the FL is. But I would like to see some f/1.4 shorter lenses
that only work with the smaller sensors. If you only have an image
circle large enough for the small sensors the lens should be cheap to
produce.

Scott

On 21 Oct 2006 18:14:23 -0700, "Scott W" <> wrote:

> wrote:
>> I'm back with more silly / newbie questions...
>>
>> In the 24 x 36 mm world, a normal lens is 50mm, normal because it offers the
>> same angle of vision as the human eye. Now, this might be an error, my
>> understanding is that at the equivalent quality, a normal lens is cheaper to
>> make than either a wide angle and/or a telephoto lens. At the same time,
>> it is possible to make normal lenses faster than any other type of lenses.
>>
>> My assumption here is because with the normal lenses you don't have to bend
>> the light at weird angles the way it's done with wide an tele lenses. True /
>> false ?
>Sort of, less bending then a wide angle lens and smaller elements then
>a telephoto lens. There is a sweet spot when lenses are the cheapest
>to make and still be fast and that would seem to be right around 50mm
>for a FF camera.
>
>For those how have not had the joy of trying to design a wide angle
>lens you can't make one without some pretty short radius surfaces and
>this dictates some pretty tight tolerances in alignment between the
>elements. You also need more elements for a wide angle lens.
>
>> Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
>> is 33mm. Right ?
>>
>> So, are we going to see cheap 33 mm lens, and faster than what we see
>> today ?
>Well getting any lens faster then about 1.2 if pretty hard no matter
>how short the FL is. But I would like to see some f/1.4 shorter lenses
>that only work with the smaller sensors. If you only have an image
>circle large enough for the small sensors the lens should be cheap to
>produce.
>
>Scott


I wondered about the 135 MM lenses for full frame 35 mm film, it used
to seem to me they were quite inexpensive relative to other focal
lengths.

<> wrote:
> I'm back with more silly / newbie questions...
>
> In the 24 x 36 mm world, a normal lens is 50mm, normal because it offers
> the
> same angle of vision as the human eye.

The "normal" lens offers neither the wide angle capability of the human eye
(looking straight ahead, one's peripheral FOV is much closer to what a 20mm
lens sees) nor the narrow angle of the central section where our vision is
the sharpest.

It looks to me that "normal" is a FOV that is easy to create optically
(anything wider would be difficult with the three (or fewer) element lenses
used in early P&S cameras) and not too long to be inconvenient (anything
longer would make the (what is now medium format) P&S cameras that appeared
starting in 1900 be bulkier than would be convenient.

FWIW, Canon's three simplest lenses are the 50/1.8 (6 elements), 35/2.0 (7
elements), and 90/2.8 TSE (6 elements).

> Now, this might be an error, my
> understanding is that at the equivalent quality, a normal lens is cheaper
> to
> make than either a wide angle and/or a telephoto lens. At the same time,
> it is possible to make normal lenses faster than any other type of lenses.

From looking at MTF curves, my impression is that 50mm lenses fall into the
"wide angle" camp. This is because pretty much all lenses longer than normal
(e.g. the 100/3.5 Hasselblad lens, the 110/2.8 Mamiya (both of which are
only slightly longer than normal), and all the Canon/Nikon primes 85mm and
over) retain excellent sharpness right out to the corners, whereas pretty
much every lens normal to shorter (including the Hassy 80/2. shows
significantly reduced contrast at the corners.

> My assumption here is because with the normal lenses you don't have to
> bend
> the light at weird angles the way it's done with wide an tele lenses. True
> /
> false ?

Longer lenses have a much easier time of it. They're physically larger, and
thus more expensive.

Also, until recently, the normal lenses were produced in vast quantities
compared to any other lens, and thus were cheaper.

> Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
> is 33mm. Right ?
>
> So, are we going to see cheap 33 mm lens, and faster than what we see
> today ?

The Sigma 30/1.4 is fairly old news. Big and expensive, though. Unlike FF
normal lenses, it won't be produced in large quantities.

David J. Littleboy
Tokyo, Japan

"Charles" <> wrote:

> I wondered about the 135 MM lenses for full frame 35 mm film, it used
> to seem to me they were quite inexpensive relative to other focal
> lengths.

You mean like the Canon 135/2.0? (List price in Japan is about US$1100, US
street price is over US$800.)

David J. Littleboy
Tokyo, Japan

"David J. Littleboy" <> writes:
> You mean like the Canon 135/2.0? (List price in Japan is about US$1100, US
> street price is over US$800.)

Back in the day, the situation wasn't anything like that. A top
quality 135/2.8 was around $150. A not-so-top quality 135/1.8 was
under $200. I got mine for $60 used at a camera store.

Today the 30/1.4 Sigma cost about as much as a full frame 35/1.4
Nikkor used to cost. The Nikkor is now about $700 new, but that's
because all the MF Nikkors are now quite expensive given the rarefied
demand for them. I got mine used for around $150 on ebay a couple
years ago.

<> wrote in message news:ygz_g.167589$1T2.130280@pd7urf2no...
> I'm back with more silly / newbie questions...
>
> In the 24 x 36 mm world, a normal lens is 50mm, normal because it offers
> the
> same angle of vision as the human eye. Now, this might be an error, my
> understanding is that at the equivalent quality, a normal lens is cheaper
> to
> make than either a wide angle and/or a telephoto lens. At the same time,
> it is possible to make normal lenses faster than any other type of lenses.
>
> My assumption here is because with the normal lenses you don't have to
> bend
> the light at weird angles the way it's done with wide an tele lenses. True
> /
> false ?
>
> Now here is the real question. With the 15 x 23 mm (aps-c) sensors, normal
> is 33mm. Right ?
>
> So, are we going to see cheap 33 mm lens, and faster than what we see
> today ?
>
>
> Thanks.
>
>

Not a silly question at all. That is what you should see...however the
camera companies are taking this opportunity to slip in a major price
increase by creating APS-C lenses and not doing this. (Just like Danon
reducing the weight of their yogurt by 25% while keeping the price the
same...the sneaky price increases are the ones that sell you less for the
same price and those really irritate me.) Also, if you compare normal
lenses for view cameras with normal lenses for medium format with normal
lenses for 35mm, you'll also notice that they get cheaper AND faster with
smaller coverage area...so, I'd assume that your 33mm lens should be a
f/1.0-1.2 and cheaper than a 50mm f/1.4 for a 35mm camera...but, I am not
holding my breath for such a thing.

George

"george" <> writes:
> smaller coverage area...so, I'd assume that your 33mm lens should be a
> f/1.0-1.2 and cheaper than a 50mm f/1.4 for a 35mm camera...but, I am not
> holding my breath for such a thing.

There was a 40/1.4 and 42/1.2 for the Olympus Pen F half-frame 35mm
system, whose image area was similar in size to APS-C. But I think
that was easier to do because the whole camera was scaled down
compared with a 35mm camera, including the mount-to-film distance.
The 35mm-descended DSLR system cameras are fundamentally
malproportioned. Canon implemented a workaround for that in some of
the cheap digital EOS cameras and lenses (EF-S, I think), but I think
they didn't dare extend it to the higher end models.

Maybe there will be some fast normal primes for the 4/3 system. For
35mm-based systems, I think we should consider APS-C sensors to be a
cost-imposed stopgap, and 24x36mm sensors should become the norm as
technology improves in the future.