Alfred Molon wrote:
> What exactly happens when a camera is set to macro mode?
>
> And why are some lenses "macro lenses" while others are not? Can a lens
> which is not a macro lens take close-ups?
It really just puts more distance between the lens elements and the
sensor, decreasing both minimum focusing distance and total light
entering the sensor. It will often design some compromise in the overall
lens design.
The best way to do this is to buy extension tubes. You can get miniscule
focusing distances (some lenses work better than others with them), but
you lose the ability to focus to infinity while they're mounted.
Alfred Molon wrote:
> What exactly happens when a camera is set to macro mode?
>
> And why are some lenses "macro lenses" while others are not? Can a
> lens which is not a macro lens take close-ups?
Which camera?
Usually macro lenses have better performance than "standard" lenses in the
1:1 reproduction region as they are designed to work at that ratio,
whereas standard lenses are designed for typical "near infinity" subject
distances. Another example: field flatness may be better in a macro lens.
In article <SS1dk.23588$E41.20269@text.news.virginmedia.com >, David J
Taylor says...
> Which camera?
>
> Usually macro lenses have better performance than "standard" lenses in the
> 1:1 reproduction region as they are designed to work at that ratio,
> whereas standard lenses are designed for typical "near infinity" subject
> distances. Another example: field flatness may be better in a macro lens.
Well, all cameras I've used so far had a macro mode and to be fair even
the Sony A350 has one. But the CZ 16-80 lens for instance is not marked
as macro, while instead the Tamron 70-300 has a macro mode available
between 180 and 300mm focal length. I'm wondering what on earth this
macro mode means and why it's only available between 180mm and 300mm.
--
Alfred Molon wrote:
[]
> Well, all cameras I've used so far had a macro mode and to be fair
> even the Sony A350 has one. But the CZ 16-80 lens for instance is not
> marked as macro, while instead the Tamron 70-300 has a macro mode
> available between 180 and 300mm focal length. I'm wondering what on
> earth this macro mode means and why it's only available between 180mm
> and 300mm.
Alfred,
I think that there are several different things here:
- cameras with a "macro mode" usually mean: (a) the focus range is
extended to include nearer objects than normal and perhaps (b) a slower
focus speed is used.
- The Tamron, i suspect, allows a slightly different internal arrnagement
of its elements, but one which only works in the focal lens range you
stated. It will allow you to focus much close than normal.
- a true "macro lens" is likely to be an expensive fixed-focus lens,
optimised for excellent performance in the reproduction range 1:2 (half
scale) to 1:1.
In article <Dn3dk.23629$E41.16533@text.news.virginmedia.com >, David J
Taylor says...
> - The Tamron, i suspect, allows a slightly different internal arrnagement
> of its elements, but one which only works in the focal lens range you
> stated. It will allow you to focus much close than normal.
I read the minimum focus distance for this lens in macro mode is around
1.20m.
> - a true "macro lens" is likely to be an expensive fixed-focus lens,
> optimised for excellent performance in the reproduction range 1:2 (half
> scale) to 1:1.
Well, compact cameras excel at macro mode because the sensor is smaller.
With a DLSR instead you have to buy an expensive dedicated lens.
--
Alfred Molon wrote:
> In article <Dn3dk.23629$E41.16533@text.news.virginmedia.com >, David J
> Taylor says...
>
>> - The Tamron, i suspect, allows a slightly different internal arrnagement
>> of its elements, but one which only works in the focal lens range you
>> stated. It will allow you to focus much close than normal.
>
> I read the minimum focus distance for this lens in macro mode is around
> 1.20m.
>
>> - a true "macro lens" is likely to be an expensive fixed-focus lens,
>> optimised for excellent performance in the reproduction range 1:2 (half
>> scale) to 1:1.
>
> Well, compact cameras excel at macro mode because the sensor is smaller.
> With a DLSR instead you have to buy an expensive dedicated lens.
Or a $100 50/1.8 and a $169 set of Kenko extension tubes, which can then
be reused on other lenses. This combo allows you to take shots like this:
Alfred Molon wrote:
> In article <Dn3dk.23629$E41.16533@text.news.virginmedia.com >, David J
> Taylor says...
>
>> - The Tamron, i suspect, allows a slightly different internal arrnagement
>> of its elements, but one which only works in the focal lens range you
>> stated. It will allow you to focus much close than normal.
>
> I read the minimum focus distance for this lens in macro mode is around
> 1.20m.
That's darn close for 300mm (450mm equivalent).
>> - a true "macro lens" is likely to be an expensive fixed-focus lens,
>> optimised for excellent performance in the reproduction range 1:2 (half
>> scale) to 1:1.
>
> Well, compact cameras excel at macro mode because the sensor is smaller.
They have more DOF by default but with a DSLR you can stop down with
high ISO, flash and or a tripod & get better.
> With a DLSR instead you have to buy an expensive dedicated lens.
The larger sensor does mean you need a bigger lens. As mentioned, many
lanses can be used for good results with extension tubes including most
telephotos, or the cheap 50mm which are quite sharp. Cameras with macro
mode do the same thing (extension 'tube' built in).
Alfred Molon <alfred_molon@yahoo.com> wrote:
>What exactly happens when a camera is set to macro mode?
It enables auto-focussing to a very close range, which is normally
omitted from the autfocus range in order to speed up the focusing
process for normal photos and avoid focus hunting.
Depending on the camera model it may also select certain exposure
parameters that the manufacturer deemed optimal for macro photography.
>And why are some lenses "macro lenses"
Because they can focus so close that the sharp image of the object on
the film/sensor plane is the same (traditional), half (DX), or ~1/4
(modern marketing speak) of the object. http://en.wikipedia.org/wiki/Macro_lens has a pretty good explanation.
> while others are not?
Because they cannot be focussed to such a short distance.
>Can a lens
>which is not a macro lens take close-ups?
Alfred Molon <alfred_molon@yahoo.com> wrote:
>In article <Dn3dk.23629$E41.16533@text.news.virginmedia.com >, David J
>Taylor says...
>
>> - The Tamron, i suspect, allows a slightly different internal arrnagement
>> of its elements, but one which only works in the focal lens range you
>> stated. It will allow you to focus much close than normal.
>
>I read the minimum focus distance for this lens in macro mode is around
>1.20m.
Then Tamrom is honest about the magnification: below a focal length of
180mm at 1.2m you don't get the 1:1 or 1:2 magnification required to
call it 'macro'.
>> - a true "macro lens" is likely to be an expensive fixed-focus lens,
>> optimised for excellent performance in the reproduction range 1:2 (half
>> scale) to 1:1.
>
>Well, compact cameras excel at macro mode because the sensor is smaller.
No, they don't. The marketing departments excel in redefining the
meaning of 'macro'.
>With a DLSR instead you have to buy an expensive dedicated lens.
If DSLRS suck so badly then why don't you stick with a P&S?
Macro mode 
Linear Mode
