angle of view... Rebel XT... lens recomm.... etc.

Archived from groups: rec.photo.digital (More info?)

"Destin_FL" <mounttimmy@yahoo.com> writes:

> Hello...
> This is going to be a very remedial question for most of you; but will be worth
> a ton to me as I venture forward into SLR territory.
> Below is the text from B&H regarding a Tokina lens that will apparently fit the
> Canon Rebels. (I'm waiting for the 350)
>
> In the specs it says that the lens has an angle of view of 84
> degrees. I would think that would be wider than the kit lens that
> will be on the 350 when it ships yes? BUT.... do I have to actually
> multiply that 24mm by 1.6 factor of the camera before I get excited
> about how wide it will shoot??? So it wouldn't actually end up
> being all that 84 degrees then... Can someone explain that whole
> thing in simple terms for me?

The safe and easy thing to do is compare focal lengths. You can
compare actual focal lengths to actual focal lengths, or you can
compare 35mm-equivalent focal lengths to 35mm-equivalent focal
lengths. You *can't* compare one to the other, however, and get any
meaningful result.

The kit lens is an 18-xx, right? That's "actual" focal length. 18mm
is a *lot* wider than 24mm (also actual focal length).

Alternatively, the 18mm behaves like a 1.6x18mm (in terms of angle of
view) on the 350, and the 24mm behaves like a 1.6x24mm, so comparing
those two you see 26.4mm vs. 38.4mm; again we see that the kit lens is
*significantly* wider.

Either comparison is valid, and so of course they both give the same
answer :-) .

You can look up the 35mm-equivalent focal lengths in 35mm
angle-of-view tables to get the angle of view the two lenses will
give. Or you can find the formula, and find the exact sensor size,
and plug those in and get exact numbers out.

> What I'm trying to find is a walking around lens that surpasses/will
> surpass the 350 Kit lens, be as wide or wider, have some telephoto
> (although less important) and be under $300. Tokina, Tamron, just
> stick with the Kit lens? I'm lost!! Thanks a ton!

I doubt you'll find it. There are very few long-range lenses that go
anywhere near as wide as the kit lenses being sold with the DSLRs.
--
David Dyer-Bennet, <mailto d-b@dd-b.net>, <http://www.dd-b.net/dd-b/&gt;
RKBA: <http://noguns-nomoney.com/&gt; <http://www.dd-b.net/carry/&gt;
Pics: <http://dd-b.lighthunters.net/&gt; <http://www.dd-b.net/dd-b/SnapshotAlbum/&gt;
Dragaera/Steven Brust: <http://dragaera.info/&gt;

Archived from groups: rec.photo.digital (More info?)

David Dyer-Bennet wrote:

>> In the specs it says that the lens has an angle of view of 84
>> degrees. I would think that would be wider than the kit lens that
>> will be on the 350 when it ships yes? BUT.... do I have to actually
>> multiply that 24mm by 1.6 factor of the camera before I get excited
>> about how wide it will shoot??? So it wouldn't actually end up
>> being all that 84 degrees then... Can someone explain that whole
>> thing in simple terms for me?

The 1.6x field of view crop factor can be applied to any true lense
focal lengths. So a 24mm wide end on the Tokina will be 38.4mm field of
view. It would be very wide, certainly not what most people consider
wide angle, which is generally 35mm and wider, with 28 being the common
value to expect.

>Alternatively, the 18mm behaves like a 1.6x18mm (in terms of angle of
>view) on the 350, and the 24mm behaves like a 1.6x24mm, so comparing
>those two you see 26.4mm vs. 38.4mm; again we see that the kit lens is
>*significantly* wider.

Just a nit-pick on your math - the 18mm x 1.6 works out to 28.8mm.

>> What I'm trying to find is a walking around lens that surpasses/will
>> surpass the 350 Kit lens, be as wide or wider, have some telephoto
>> (although less important) and be under $300. Tokina, Tamron, just
>> stick with the Kit lens? I'm lost!! Thanks a ton!
>
>I doubt you'll find it. There are very few long-range lenses that go
>anywhere near as wide as the kit lenses being sold with the DSLRs.

A good walk about or everyday lense would be something in the range of
18-80mm or so. The 18mm gives you reasonably wide angle, and the long
end of 80mm is good for portraits and mild zooming.

Canon makes a 17-85 with image stabilization (IS) which is pretty good,
but rather costly for what you get. It costs almost as much as the Rebel
body. Personally, I rarely have a need for IS with lenses under about
150mm or so. And if I do, that's why I have a tripod.  

I'd like to see Canon make a 17-85 without IS for a reasonable price. It
would be a good walk about lense and give lower end users a practical
and well priced starter lense.

Archived from groups: rec.photo.digital (More info?)

What is the widest the lens will go? If it is a 24mm lens you will have to
multiply that by 1.6 to get the apparent focal length (as seen by a 35mm
user) then get the angle of view for the resulting focal length. If the lens
is wider than 24 and becomes an effective 24 on the dRebel body then the
math has been done for you.

--
http://www.chapelhillnoir.com
home of The Camera-ist's Manifesto
The Improved Links Pages are at
http://www.chapelhillnoir.com/links/mlinks00.html
A sample chapter from "Haight-Ashbury" is at
http://www.chapelhillnoir.com/writ/hait/hatitl.html

"Destin_FL" <mounttimmy@yahoo.com> wrote in message
news:sz8Xd.25799$Sn6.11078@lakeread03...
> Hello...
> This is going to be a very remedial question for most of you; but will be
worth
> a ton to me as I venture forward into SLR territory.
> Below is the text from B&H regarding a Tokina lens that will apparently
fit the
> Canon Rebels. (I'm waiting for the 350)
>
> In the specs it says that the lens has an angle of view of 84 degrees. I
would
> think that would be wider than the kit lens that will be on the 350 when
it
> ships yes? BUT.... do I have to actually multiply that 24mm by 1.6 factor
of
> the camera before I get excited about how wide it will shoot???
> So it wouldn't actually end up being all that 84 degrees then...
> Can someone explain that whole thing in simple terms for me?
>
> What I'm trying to find is a walking around lens that surpasses/will
surpass the
> 350 Kit lens, be as wide or wider, have some telephoto (although less
important)
> and be under $300. Tokina, Tamron, just stick with the Kit lens? I'm
lost!!
> Thanks a ton!
>
> Tim
>
>
> _______________
>
> The AT-X 242 AF is the first lens to start at 24mm and zoom all the way to
> 200mm. Chrome-plated brass mount plates and combination aluminum/composite
lens
> barrels reduce weight while maintaining strength and durability.
> Optically, it uses high quality optical glass multicoated lens elements.
Two
> aspherical lens elements and one SD (super low dispersion) glass element
are
> employed in the optical design to insure sharpness across the film plane.
The
> aspherical elements are each molded as one piece of optical glass, rather
than a
> resin laminated to a glass core.
>
> An internal focusing mechanism gives this lens fast autofocus. The lens
front
> does not rotate during focusing-a great advantage when a special effects
filter
> such as a circular polarizer is used. Focus distance is indicated on the
manual
> focus ring.
>
> Like the rest of the lenses in the AT-X series, The AT-X 242 AF is what is
> commonly referred to as a parafocal lens, meaning when focus is achieved
at a
> telephoto focal length, it is possible to zoom back to a wide angle and
maintain
> focus on the subject.
>
>
>

Archived from groups: rec.photo.digital (More info?)

On Tue, 08 Mar 2005 03:00:58 +0000, Destin_FL wrote:

> Hello...
> This is going to be a very remedial question for most of you; but will
> be worth a ton to me as I venture forward into SLR territory. Below is
> the text from B&H regarding a Tokina lens that will apparently fit the
> Canon Rebels. (I'm waiting for the 350)
>
> In the specs it says that the lens has an angle of view of 84 degrees. I
> would think that would be wider than the kit lens that will be on the
> 350 when it ships yes? BUT.... do I have to actually multiply that 24mm
> by 1.6 factor of the camera before I get excited about how wide it will
> shoot??? So it wouldn't actually end up being all that 84 degrees
> then... Can someone explain that whole thing in simple terms for me?

The specifications are clearly for 35mm film camera. On a digital rebel/XT
that 24mm (84 deg diagnonal angle of view) would become something like
38mm (~60 deg angle of view). Wide but probably not wide enough for a
general purpose walk around lens. The other end of the zoom would become
equivalent to a 320mm lens. It may prove to be too long a zoom for general
purpose, but not long enough for wildlife photography, etc.

> What I'm trying to find is a walking around lens that surpasses/will
> surpass the 350 Kit lens, be as wide or wider, have some telephoto
> (although less important) and be under $300. Tokina, Tamron, just stick
> with the Kit lens? I'm lost!! Thanks a ton!
>
For a general purpose zoom lens I would suggest something from 17/18mm at
the wide end (~70 deg angle of view, equivalent to 28mm lens on film
cameras) to something around 100/125mm (150/200mm equivalent for 35mm film
camera) at the tele end. If tele is not important to you then you can
settle for something around 70/80mm (110/130mm for film camera).

Tokina lenses are generally good. I used a 17mm prime & a 28-70mm zoom
lens for many years with 35mm slr. Of course, cannot commnet on the
particular lens you have mentioned as I have never used it.

--

Gautam Majumdar

Please send e-mails to gmajumdar@freeuk.com

Archived from groups: rec.photo.digital (More info?)

Bill <bill@c.a> writes:

> David Dyer-Bennet wrote:
>
>>> In the specs it says that the lens has an angle of view of 84
>>> degrees. I would think that would be wider than the kit lens that
>>> will be on the 350 when it ships yes? BUT.... do I have to actually
>>> multiply that 24mm by 1.6 factor of the camera before I get excited
>>> about how wide it will shoot??? So it wouldn't actually end up
>>> being all that 84 degrees then... Can someone explain that whole
>>> thing in simple terms for me?
>
> The 1.6x field of view crop factor can be applied to any true lense
> focal lengths. So a 24mm wide end on the Tokina will be 38.4mm field of
> view. It would be very wide, certainly not what most people consider
> wide angle, which is generally 35mm and wider, with 28 being the common
> value to expect.
>
>>Alternatively, the 18mm behaves like a 1.6x18mm (in terms of angle of
>>view) on the 350, and the 24mm behaves like a 1.6x24mm, so comparing
>>those two you see 26.4mm vs. 38.4mm; again we see that the kit lens is
>>*significantly* wider.
>
> Just a nit-pick on your math - the 18mm x 1.6 works out to 28.8mm.

Oops, sorry; did it quick in my head, and the result passed sanity
check.
--
David Dyer-Bennet, <mailto d-b@dd-b.net>, <http://www.dd-b.net/dd-b/&gt;
RKBA: <http://noguns-nomoney.com/&gt; <http://www.dd-b.net/carry/&gt;
Pics: <http://dd-b.lighthunters.net/&gt; <http://www.dd-b.net/dd-b/SnapshotAlbum/&gt;
Dragaera/Steven Brust: <http://dragaera.info/&gt;

Archived from groups: rec.photo.digital (More info?)

Destin_FL wrote:
>
> Hello...
> This is going to be a very remedial question for most of you; but will be worth
> a ton to me as I venture forward into SLR territory.
> Below is the text from B&H regarding a Tokina lens that will apparently fit the
> Canon Rebels. (I'm waiting for the 350)
>
> In the specs it says that the lens has an angle of view of 84 degrees. I would
> think that would be wider than the kit lens that will be on the 350 when it
> ships yes? BUT.... do I have to actually multiply that 24mm by 1.6 factor of
> the camera before I get excited about how wide it will shoot???
> So it wouldn't actually end up being all that 84 degrees then...
> Can someone explain that whole thing in simple terms for me?
>
> What I'm trying to find is a walking around lens that surpasses/will surpass the
> 350 Kit lens, be as wide or wider, have some telephoto (although less important)
> and be under $300. Tokina, Tamron, just stick with the Kit lens? I'm lost!!
> Thanks a ton!
>
> Tim

I have a 300D, and I bought the Canon 17-85 mm IS lens for just the
purpose you mention, a walk-around lens with reasonable range. It has
proven to be a delightful lens to use, and is sharper than the 18-55 kit
lens as well. It's not under $300, though, but if you can stretch the
extra, it'll be worth it.

Colin