Question: Macro 'filters' - do they work?

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

Hi Bobby
The screw on lenses you mention are known as Plus lenses and usually come
in groups of three: Plus 1, Plus 2, Plus 3. They are fixed focus. The +1
lens focuses at 1 meter, +2 at 1/ 2meter, and +3 at 1/3 meter.

Obviously they are not as good as a full-featured macro lens. However they
are an excellent and inexpensive way to get into macro photography. Next up
the line costwise as well as quality-wise would be a lens extender: a device
which fits between the lens and camera. Image quality is superior to the
filters because there is some image degradation anytime a filter is placed
in front of a lens.

Finally, and not truly macro, would be to use a long lens, perhaps a 75 -
300 zoom lens. You can get fantastic "closeups" this way. Although not
truly macro, photos of flowers for example can be spectacular.

I have been an ardent macro photographer for many years, and began with the
Plus lenses and then worked my way up.

Hope this helps.

Bernard

"BD" <bobby_dread@hotmail.com> wrote in message
news:1122389166.524434.38160@g49g2000cwa.googlegroups.com...
> Hey all.
>
> I recently spotted some macro lenses that would fit my Rebel 300D.
> They're not what I expected - they take the form of a small stack of
> filter-style lenses, that are supposed to just screw onto the 18-55 kit
> lens. They're basically small magnifying lenses of varying powers
>
> I can't imagine that this kind of kit would be nearly as good as a
> 'proper' Canon macro lens, but has anyone used this style of kit? Can
> you get results that are worth the $70 investment?
>
> Thanks!
>
> BD
>

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

In article <8osFe.3443$Ow4.1432186@twister.nyc.rr.com>, Bernard Saper
<bsaper@nyc.rr.com> writes
>Hi Bobby
>The screw on lenses you mention are known as Plus lenses and usually come
>in groups of three: Plus 1, Plus 2, Plus 3. They are fixed focus. The +1
>lens focuses at 1 meter, +2 at 1/ 2meter, and +3 at 1/3 meter.

This could be slightly misleading.

The supplementary lenses (more commonly known as "close-up lenses" ) are
denoted with the power of each lens in dioptres. A +1 lens - 1 dioptre -
has a focal length of 1 metre, a +2 of 0.5 metre, and an N dioptre lens
has a focal length of 1/N metres.

The lenses do not make your system "fixed focus" at all, they change the
focussing range, making it closer. Thus, if you take a simple example of
my Canon 50mm f/1.4 lens, which has a closest focus distance of 0.45m
and a maximum magnification of 0.15, placing a +1 close-up lens on it
will make it approximately 47.6mm focal length and have a maximum
magnification of about 0.21. A +3 lens will make it a 43.5mm lens with a
maximum magnification of 0.32, i.e. about twice that for the +1.

However, it is important to realise that this is just the maximum
magnification; the focus mechanism of the primary lens still works. The
50mm lens with +1 supplementary will focus from approximately 1 metre to
approximately 0.28 metres. Similarly the example with the +3
supplementary will range from 0.33m to 0.178m

Furthermore, these calculations will be completely different for a
primary lens of different focal length, or even for one of the same
focal length but a different close focus distance.

(BTW, all these distances are somewhat approximate as the formulae
assume a simple lens, and that there is zero separation between the
primary lens and the supplementary; neither is of course true in
practice, and also some camera lenses change focal length themselves as
they are focussed closer.)
>
>Obviously they are not as good as a full-featured macro lens.

True.

> However they
>are an excellent and inexpensive way to get into macro photography.

Also true.

> Next up
>the line costwise as well as quality-wise would be a lens extender: a device
>which fits between the lens and camera. Image quality is superior to the
>filters because there is some image degradation anytime a filter is placed
>in front of a lens.

There is also image degradation caused by using a primary lens at a
focal distance well away from those for which it was designed.
Aberrations are controlled as well as possible over the intended range
of conjugate distances, but may go well out of control outside that
range. Zoom lenses and highly asymmetric designs are likely to be worse
here. In some cases the results may be worse than those with close up
lenses.
>
>Finally, and not truly macro, would be to use a long lens, perhaps a 75 -
>300 zoom lens. You can get fantastic "closeups" this way.

No you can't; the fact that your object distance is much larger for a
long focal length does not say anything about the magnification ratio.
Long lenses typically have no greater magnification ratios than short
lenses, but you just get to stand further away to do it. In that sense,
and that sense only, you get "close-ups" that way.

Now a long lens with a close up lens attached can indeed give some very
high magnifications from a distance.

Note that a close up lens will have a greater effect (in terms of
magnification achievable) on a long lens than a short one, whereas
extension tubes have less effect on long lenses.

> Although not
>truly macro, photos of flowers for example can be spectacular.
>
True.

To the scientist in this field, and to the stickler for accuracy,
"macro" as a term applies only to pictures with a magnification ratio of
1.0 or greater (actually, in practical terms, up to 25 or 50, beyond
which you need a compound microscope).

David
--
David Littlewood

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

Hmm.. Well, for the moderate cost, it seems like they could have a
variery of uses. I think I'll grab a set!

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

In article <1122413841.326572.273690@f14g2000cwb.googlegroups.com>, BD
<bobby_dread@hotmail.com> writes
>David: Is it true that these lenses can make autofocus functionality
>fail, and that you're pretty much stuck with manual focus if you choose
>to use them?
>
>No biggie if so - I'm just hoping to answer all the questions before I
>buy.
>
I have used close up lenses on an AF lens quite normally. In fact, the
reason I got my first AF camera (EOS 10) was that my daughter wanted
some pictures of her hamster, and the little blighters move so fast I
couldn't keep them in focus manually and I was getting about one sharp
picture in ten. The AF camera/lens with a close up lens was just right
for the job - I wasn't too concerned to get a 12x16 blow up, just sharp
5x7s, and it was fine. The rapid AF of the EF lens (a 35-135 USM) helped
a lot. Of course, other makers' AF speeds have improved a lot, but at
this time (early 90s) most others were much slower.

One advantage of the supplementary lens I forgot to mention is that it
does not reduce the effective aperture of the lens. Extension tubes,
OTOH, do give a reduced effective aperture. This can sometimes cause the
AF to slow down.

David
--
David Littlewood

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

BD wrote:
> Thanks for your insights, David.
>
> All in all, I think that a set of these lenses would be worth the
> relatively low cost. It sounds like they have a few potential
> applications.
>
> Cheers,
>
> BD

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

Charlie Self wrote:
> Charlie Self wrote:
> > BD wrote:
> > > Thanks for your insights, David.
> > >
> > > All in all, I think that a set of these lenses would be worth the
> > > relatively low cost. It sounds like they have a few potential
> > > applications.
> > >
> > > Cheers,
> > >
> > > BD
>
> I have GOT to do something about this GD over-sensitive mouse!
>
> I've used front element filters for photography for something over 20
> years. In general, the results are very satisfying, though, as someone
> else mentioned, edge sharpness isn't that great.
>
> Compared to a true macro lens, there are major lacks, but my current
> front element set-up allows me to use my Pentax 16-45 with little or no
> light loss, retaining the zoom, among other things my 100mm macro won't
> do.
>
> The set I have is an off-brand, fortuitous purchase (I think), with +1,
> +2 and +4.

Off-brand. Yeah, right. They're Tiffen, so I'm less surprised at the
result. I think I've bought too much gear of various types in the past
18 months, as I can't remember what half of it is.

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

Dave Martindale wrote:

> A step up from these are achromatic closeup lenses. Each "lens" is
> actually a 2-layer sandwich of different glasses which provides better
> colour correction than the single-element lenses. The Canon 500D and
> 250D closeup lenses are achromats. Some high-end filter makers also
> sell achromatic closeup lenses.
>
> Neither of the above are as good as true macro lenses, but they are in
> an entirely different price class.

BD,
I would recommend that you get the achromatic closeup lenses.
I have tried the simple ones and did not get very good results.
The achromatic ones do work much better. I used a Nikon one
for years on my Canon lenses (if I remember correctly, Nikon
came out with them first, so that is why I got a Nikon).
But I've upgraded to a canon 180 mm f/3.5 canon macro lens.
It is the sharpest lens I've seen (and I have quite a few
lenses and used many more in my work).

Roger

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

Edge quality is likely not going to be a big concern. I will likely be
using a very wide aperture, so background objects will be out of focus
anyway.

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

Don Stauffer <stauffer@usfamily.net> writes:

>Another advantage of supplemental lenses over zoom macros is that many
>of the macro zooms are macro only on longest focal length.

>Table top and macro photography often demands shorter focal lengths to
>give a true "close up" perspective. In fact, when used on a
>single-focal-length lens, the supplemental (closeup) lens actually
>reduces focal length of main lens slightly.

On the other hand, some other so-called "macro" zooms give their macro
effect only at the shortest focal length, and you end up with an
extremely short working distance, which can be a real pain.

Dave

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

Yes, I just got the same caution from a friend today. Oh well - it's
all a learning process, I guess...

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

I'd probably just _make_ something. Posterboard accordion folder with
thin felt glued to all the surfaces or some such thing.

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

Maybe it'll be photography by attrition - find a subject, take 200
shots - one of them almost _has_ to work.