Velocity Reviews - Computer Hardware Reviews

Velocity Reviews > Newsgroups > Computing > Digital Photography > Some Very Basic Questions...

Reply
Thread Tools

Some Very Basic Questions...

 
 
Ben
Guest
Posts: n/a
 
      09-19-2004
Hi there, as you may have guessed from the thread title, i am new at
SLR photography, but i would very much like to get into it.
But first i have a couple of questions:
Is there anywhere on the www, or a book, that could explain to me the
most basic of things, such as when a lens is described as being 18-55
mm, what does this measurement actually refer to?
Also, i would like to choose a lens for my D SLR body (Canon EOS), but
have no idea which one to pick. Aside from giving me all of the fancy
specs, most sites i come across do not actually explain things in a
way that is easy for a COMPLETE beginner to understand. To start off
with i would like a lens that is good for taking day to day shots, i
suppose a middle of the road, best of both worlds lens that will help
me to get used to taking regular kinds of shots.
I would very much appreciate it if anyone could get back to me to give
me a pointer in the right direction here.
Many thanks, Ben.
 
Reply With Quote
 
 
 
 
GT40
Guest
Posts: n/a
 
      09-19-2004
www.dprewview.com might help you. The is some good info on the Canon
website. For ultra basic info try, www.howstuffworks,com

For your lens the Canon 28-135mm lens would be a good choice.

On 18 Sep 2004 17:46:57 -0700, http://www.velocityreviews.com/forums/(E-Mail Removed) (Ben) wrote:

>Hi there, as you may have guessed from the thread title, i am new at
>SLR photography, but i would very much like to get into it.
>But first i have a couple of questions:
>Is there anywhere on the www, or a book, that could explain to me the
>most basic of things, such as when a lens is described as being 18-55
>mm, what does this measurement actually refer to?
>Also, i would like to choose a lens for my D SLR body (Canon EOS), but
>have no idea which one to pick. Aside from giving me all of the fancy
>specs, most sites i come across do not actually explain things in a
>way that is easy for a COMPLETE beginner to understand. To start off
>with i would like a lens that is good for taking day to day shots, i
>suppose a middle of the road, best of both worlds lens that will help
>me to get used to taking regular kinds of shots.
>I would very much appreciate it if anyone could get back to me to give
>me a pointer in the right direction here.
>Many thanks, Ben.


 
Reply With Quote
 
 
 
 
David Dyer-Bennet
Guest
Posts: n/a
 
      09-19-2004
(E-Mail Removed) (Ben) writes:

> Hi there, as you may have guessed from the thread title, i am new at
> SLR photography, but i would very much like to get into it.
> But first i have a couple of questions:
> Is there anywhere on the www, or a book, that could explain to me the
> most basic of things, such as when a lens is described as being 18-55
> mm, what does this measurement actually refer to?
> Also, i would like to choose a lens for my D SLR body (Canon EOS), but
> have no idea which one to pick. Aside from giving me all of the fancy
> specs, most sites i come across do not actually explain things in a
> way that is easy for a COMPLETE beginner to understand. To start off
> with i would like a lens that is good for taking day to day shots, i
> suppose a middle of the road, best of both worlds lens that will help
> me to get used to taking regular kinds of shots.
> I would very much appreciate it if anyone could get back to me to give
> me a pointer in the right direction here.


I can't unfortunately point to a good book; I don't have fond memories
of any one book that really taught me this stuff, and if I did it
would be outdated and out of print by now. I hope somebody comes
through on this one for you, because that's the right question to ask!

The "18-55mm" means that lens is a "zoom" lens (probably technically a
varifocal rather than a zoom, but almost nobody cares about that
distinction any more), and it can be set for any "focal length"
between 18mm and 55mm. The "focal length" of a lens is the distance
in back of "the lens" (technically one specific one of the "nodal points" of
the lens but my optics doesn't go that far; for practical purposes
about the middle of most camera lenses) at which an image of something
"at infinity" in front of the lens will be brought into sharp focus.

In *practice* what the focal length means is the angle of view of the
lens. Smaller numbers mean wider angle of view. Note that the angle
of view isn't *just* a property of the lens; it's a property of the
combination of the lens, and the film or sensor it's placed in front
of. The lens projects a circular image, which the sensor crops to a
rectangle of some particular shape. The size of the circular image
(or, often, the lower quality of the outer edges) set a practical
limit on how big a sensor/piece of film you can use that lens to take
a photo onto. This is why you need a *different* 200mm lens for a
35mm camera than you do for a 4x5 view camera; the one made for a 35mm
camera projects far too small an image to cover a 4x5 sheet of film.
And why the two lenses of the same focal have different angles of view
*when used on their intended format film*.

Kinda by convention, kinda by observation of how the human eye works,
a focal length about equal to the diagonal of the film (or sensor) is
considered "normal". For 35mm film, a 50mm lens is considered
normal. For a 1.6x crop factor digital SLR a 30mm lens would be
about "normal" in the same sense.

So that 18-55mm zoom lens would be a pretty good choice for a
"most-of-the-time" lens on the EOS 300 -- it'd give you coverage from
moderate wideangle to mild telephoto. Which is why that lens was
introduced. Like most cheaper zooms, it's fairly "slow" -- low
light-gathering power, so not too good for shooting in low light
without flash. Fast lenses are expensive, large, and heavy; like most
of life, photography is full of tradeoffs.
--
David Dyer-Bennet, <(E-Mail Removed)>, <http://www.dd-b.net/dd-b/>
RKBA: <http://noguns-nomoney.com/> <http://www.dd-b.net/carry/>
Pics: <http://dd-b.lighthunters.net/> <http://www.dd-b.net/dd-b/SnapshotAlbum/>
Dragaera/Steven Brust: <http://dragaera.info/>
 
Reply With Quote
 
Tony Morgan
Guest
Posts: n/a
 
      09-19-2004
In message <(E-Mail Removed)-b.net>, David Dyer-Bennet
<(E-Mail Removed)> writes
Snipped....

>The "18-55mm" means that lens is a "zoom" lens (probably technically a
>varifocal rather than a zoom, but almost nobody cares about that
>distinction any more), and it can be set for any "focal length" between
>18mm and 55mm. The "focal length" of a lens is the distance in back of
>"the lens" (technically one specific one of the "nodal points" of the
>lens but my optics doesn't go that far; for practical purposes about
>the middle of most camera lenses) at which an image of something "at
>infinity" in front of the lens will be brought into sharp focus.


In simple terms:

focal length = (OD x IS) / OS where

OD = Object Distance
IS = Image Size
OS = Object Size

So if you have a 1m subject 20m from your camera, and that object gives
an image size on the CCD of 2mm, then the focal length is 40mm.

Snipped......
--
Tony Morgan
http://www.camcord.info
 
Reply With Quote
 
Frank ess
Guest
Posts: n/a
 
      09-19-2004
If the OP is interested in a photography primer that includes some of
the best photographs you'll ever see, look for a set of The Time Life
Library of Photography. Years old (20?), the principles are current, and
the underlying educational experience valuable.

Numerous sets and individual volumes on eBay at any juncture, e.g.:
http://search.ebay.com/time-life-pho...sortpropertyZ1


--
Frank ess


 
Reply With Quote
 
Tony Morgan
Guest
Posts: n/a
 
      09-20-2004
In message <(E-Mail Removed) >, Ben
<(E-Mail Removed)> writes
>Hi there, as you may have guessed from the thread title, i am new at
>SLR photography, but i would very much like to get into it.
>But first i have a couple of questions:
>Is there anywhere on the www, or a book, that could explain to me the
>most basic of things, such as when a lens is described as being 18-55
>mm, what does this measurement actually refer to?
>Also, i would like to choose a lens for my D SLR body (Canon EOS), but
>have no idea which one to pick. Aside from giving me all of the fancy
>specs, most sites i come across do not actually explain things in a
>way that is easy for a COMPLETE beginner to understand. To start off
>with i would like a lens that is good for taking day to day shots, i
>suppose a middle of the road, best of both worlds lens that will help
>me to get used to taking regular kinds of shots.
>I would very much appreciate it if anyone could get back to me to give
>me a pointer in the right direction here.


Try Shoot Like a Pro! Digital Photography ISBN 0-07-222949-7 and
Digital Photography Hacks ISBN 0-596-00666-7

If you're without scruples, you can find these on E-Mule as PDFs.
--
Tony Morgan
http://www.camcord.info
 
Reply With Quote
 
David Dyer-Bennet
Guest
Posts: n/a
 
      09-20-2004
"Frank ess" <(E-Mail Removed)> writes:

> If the OP is interested in a photography primer that includes some of
> the best photographs you'll ever see, look for a set of The Time Life
> Library of Photography. Years old (20?), the principles are current, and
> the underlying educational experience valuable.


I've got that; my parents got it for me fairly early in my career.
Even then, I found it was fairly superficial, and didn't go into much
detail about anything. But it *is* filled with very fine pictures,
superbly reproduced, and that's worth a fair amount.
--
David Dyer-Bennet, <(E-Mail Removed)>, <http://www.dd-b.net/dd-b/>
RKBA: <http://noguns-nomoney.com/> <http://www.dd-b.net/carry/>
Pics: <http://dd-b.lighthunters.net/> <http://www.dd-b.net/dd-b/SnapshotAlbum/>
Dragaera/Steven Brust: <http://dragaera.info/>
 
Reply With Quote
 
Matt Ion
Guest
Posts: n/a
 
      09-21-2004
Ben wrote:

> Hi there, as you may have guessed from the thread title, i am new at
> SLR photography, but i would very much like to get into it.
> But first i have a couple of questions:
> Is there anywhere on the www, or a book, that could explain to me the
> most basic of things, such as when a lens is described as being 18-55
> mm, what does this measurement actually refer to?
> Also, i would like to choose a lens for my D SLR body (Canon EOS), but
> have no idea which one to pick. Aside from giving me all of the fancy
> specs, most sites i come across do not actually explain things in a
> way that is easy for a COMPLETE beginner to understand. To start off
> with i would like a lens that is good for taking day to day shots, i
> suppose a middle of the road, best of both worlds lens that will help
> me to get used to taking regular kinds of shots.
> I would very much appreciate it if anyone could get back to me to give
> me a pointer in the right direction here.
> Many thanks, Ben.


All these questions and more have been asked in this group regularly.
Try going to groups.google.com and doing a search - they have pretty
much everything archived back to the beginning of Usenet.
 
Reply With Quote
 
 
 
Reply

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
I found some very odd behaviour in Python's very basic types Sunjay Varma Python 4 03-10-2011 05:05 PM
A very **very** basic question mdh C Programming 57 09-26-2008 03:25 PM
very very basic question aghazalp Python 6 04-02-2006 09:35 PM
Very very very basic question Peter C Programming 14 02-14-2005 09:46 AM
Quick Book file access very very very slow Thomas Reed Computer Support 7 04-09-2004 08:09 PM



Advertisments