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macros and close-up "filters"

 
 
Tony Belding
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      01-01-2007
Just wondering if somebody could help me sort out the pluses and
minuses of a real (i.e. expensive) macro lens, as compared with the
close-up lenses that thread on like a filter? I notice there are cheap
close-up sets with different diopter strengths, and I also noticed
there are two-element close-up lenses which cost more. . .

I'm interested mainly in product shooting (such as, for eBay) where I
want decent-looking results, but not trying to count the grains of
pollen stuck to a honeybee. I was thinking a close-up "filter" on a
regular 50mm or 135mm lens would probably be good enough for my
purposes, is that a fair guess?

--
Tony Belding, Hamilton Texas

 
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Cgiorgio
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      01-01-2007
Have a look at the following link:
http://www.raynox.co.jp/english/digi...300d/index.htm

(to be used with tele- lens)


"Tony Belding" <(E-Mail Removed)> schrieb im Newsbeitrag
news:2007010116492616807-zobeid@techiecom...
> Just wondering if somebody could help me sort out the pluses and minuses
> of a real (i.e. expensive) macro lens, as compared with the close-up
> lenses that thread on like a filter? I notice there are cheap close-up
> sets with different diopter strengths, and I also noticed there are
> two-element close-up lenses which cost more. . .
>
> I'm interested mainly in product shooting (such as, for eBay) where I want
> decent-looking results, but not trying to count the grains of pollen stuck
> to a honeybee. I was thinking a close-up "filter" on a regular 50mm or
> 135mm lens would probably be good enough for my purposes, is that a fair
> guess?
>
> --
> Tony Belding, Hamilton Texas
>



 
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Joseph Meehan
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      01-02-2007
Tony Belding wrote:
> Just wondering if somebody could help me sort out the pluses and
> minuses of a real (i.e. expensive) macro lens, as compared with the
> close-up lenses that thread on like a filter? I notice there are
> cheap close-up sets with different diopter strengths, and I also
> noticed there are two-element close-up lenses which cost more. . .
>
> I'm interested mainly in product shooting (such as, for eBay) where I
> want decent-looking results, but not trying to count the grains of
> pollen stuck to a honeybee. I was thinking a close-up "filter" on a
> regular 50mm or 135mm lens would probably be good enough for my
> purposes, is that a fair guess?


As you guess, the quality is not as good. How much "not" will depend on
the lens you are using it on and how close you are going. If you are
talking about something like a ring, I suggest a real macro, if you are
talking about something like a camera, you may be happy with the cheap
solution. Don't use the tele, use it (them) on the 50 mm. You may need
more than one if you will be photographing a range of sizes.

--
Joseph Meehan

Dia 's Muire duit



 
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Floyd L. Davidson
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      01-02-2007
"Joseph Meehan" <(E-Mail Removed)> wrote:
>Tony Belding wrote:
>> Just wondering if somebody could help me sort out the pluses and
>> minuses of a real (i.e. expensive) macro lens, as compared with the
>> close-up lenses that thread on like a filter? I notice there are
>> cheap close-up sets with different diopter strengths, and I also
>> noticed there are two-element close-up lenses which cost more. . .
>>
>> I'm interested mainly in product shooting (such as, for eBay) where I
>> want decent-looking results, but not trying to count the grains of
>> pollen stuck to a honeybee. I was thinking a close-up "filter" on a
>> regular 50mm or 135mm lens would probably be good enough for my
>> purposes, is that a fair guess?

>
> As you guess, the quality is not as good. How much "not" will depend on
>the lens you are using it on and how close you are going. If you are
>talking about something like a ring, I suggest a real macro, if you are
>talking about something like a camera, you may be happy with the cheap
>solution.


All was fine down to that point.

> Don't use the tele, use it (them) on the 50 mm.


No, it's the other way around. Closeup lenses have significantly
more effect when used in front of a *longer* lense. There will be
only slight difference with a 50mm lense compared to the effect using
a 135mm lense, for example.

>You may need
>more than one if you will be photographing a range of sizes.


But note that quality will suffer.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) http://www.velocityreviews.com/forums/(E-Mail Removed)
 
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Jim
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      01-02-2007

"Tony Belding" <(E-Mail Removed)> wrote in message
news:2007010116492616807-zobeid@techiecom...
> Just wondering if somebody could help me sort out the pluses and minuses
> of a real (i.e. expensive) macro lens, as compared with the close-up
> lenses that thread on like a filter? I notice there are cheap close-up
> sets with different diopter strengths, and I also noticed there are
> two-element close-up lenses which cost more. . .
>
> I'm interested mainly in product shooting (such as, for eBay) where I want
> decent-looking results, but not trying to count the grains of pollen stuck
> to a honeybee. I was thinking a close-up "filter" on a regular 50mm or
> 135mm lens would probably be good enough for my purposes, is that a fair
> guess?
>
> --
> Tony Belding, Hamilton Texas
>

In addition there are extension tubes which enable focusing closer than the
mount allows.

Which one you use depends on the nature of the use. For the one use that
you specified, a couple of close up adapters should work fine.
Just keep the aperature toward the small end of the range to reduce the
inevitable distortions.

The various diopter strengths are needed to allow for differing distances
from the lens.
For example, the focal length of one of these adapters is 1000/diopter.
Consequently, with the lens set at infinity, the furtherest distance from
the lens would be 1000/diopter.

The two element adapters are intended for use with telephoto lenses because
the simple single element lenses cause way too much degradation of the
image.

Jim


 
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Floyd L. Davidson
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      01-02-2007
"Jim" <(E-Mail Removed)> wrote:
>In addition there are extension tubes which enable focusing closer than the
>mount allows.


The problem with extension tubes is that manufacturers limit the
close focus mechanical range *because* of the generally
worsening quality of the optics as the focus distance is
reduced. Hence, a nice tack sharp lense that can focus to 1
foot may not be anything like tack sharp with enough extension
to focus it at 6 inches...

Generally though, for lenses specifically optimized for close
focus, extension tubes or bellows are nice. Macro lenses,
enlarging lenses, and regular (not zoom) lenses that are
reversed will all generally provide good results.

The above is particularly significant if close focusing also
requires a "flat field" lense. One of the big tradeoffs between
optimizing for close focus or not is a balance between
astigmatism and flatness of field. If a flat field is not
required (e.g., insect macro images) then a lense that is not
particularly noted for a flat field might well exhibit less
astigmatism, and produce a sharper image. But if the object to
be photographed is a postage stamp, a flat field lense will make
a significant difference.

>Which one you use depends on the nature of the use. For the one use that
>you specified, a couple of close up adapters should work fine.
>Just keep the aperature toward the small end of the range to reduce the
>inevitable distortions.


Using smaller apertures will extend the depth of field, and
might reduce spherical aberrations, but not the inevitable
pin cushion or barrel distortions...

>The various diopter strengths are needed to allow for differing distances
>from the lens.
>For example, the focal length of one of these adapters is 1000/diopter.
>Consequently, with the lens set at infinity, the furtherest distance from
>the lens would be 1000/diopter.


To put that into perspective, a +2 diopter will result in the
"infinity" focus position on a lense actually focusing at
1000/2, or 500mm. Which perhaps isn't really very interesting
because it doesn't indicate how *close* it will be when the
focusing mechanism is set to its closest focus setting.

>The two element adapters are intended for use with telephoto lenses because
>the simple single element lenses cause way too much degradation of the
>image.


Not true. Multi element close up lenses are "achromatic",
meaning the different elements are designed to cancel the
chromatic aberrations of each other. That works exactly the
same regardless of the focal length of the lense they are
mounted on.

However, diopters provide more dramatic magnification when
attached to longer focal length lenses, hence it is typically
more useful to put them on short or medium focal length
telephoto lenses than anything shorter. A close up lense in
front of a wide angle lense has very little effect.

--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) (E-Mail Removed)
 
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King Sardon
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      01-02-2007
On Mon, 1 Jan 2007 16:49:26 -0600, Tony Belding <(E-Mail Removed)>
wrote:

>Just wondering if somebody could help me sort out the pluses and
>minuses of a real (i.e. expensive) macro lens, as compared with the
>close-up lenses that thread on like a filter? I notice there are cheap
>close-up sets with different diopter strengths, and I also noticed
>there are two-element close-up lenses which cost more. . .
>
>I'm interested mainly in product shooting (such as, for eBay) where I
>want decent-looking results, but not trying to count the grains of
>pollen stuck to a honeybee. I was thinking a close-up "filter" on a
>regular 50mm or 135mm lens would probably be good enough for my
>purposes, is that a fair guess?


Yes, for the purposes you describe a close-up lens is an excellent
solution. The two-element ones give better results.

KS
 
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JD
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      01-02-2007
Tony Belding wrote:
> Just wondering if somebody could help me sort out the pluses and minuses
> of a real (i.e. expensive) macro lens, as compared with the close-up
> lenses that thread on like a filter? I notice there are cheap close-up
> sets with different diopter strengths, and I also noticed there are
> two-element close-up lenses which cost more. . .
>
> I'm interested mainly in product shooting (such as, for eBay) where I
> want decent-looking results, but not trying to count the grains of
> pollen stuck to a honeybee. I was thinking a close-up "filter" on a
> regular 50mm or 135mm lens would probably be good enough for my
> purposes, is that a fair guess?
>

You might want to check out John Shaw's Closeups in Nature. He covers
extentsion tubes, closeup filter lenses, lens stacking and much more.
If nothing else, his discussion of meter calibration is worth the price
of admission. Mr. Shaw shows the quality that can be produced with a
dual element filter on a zoom lens.

As you point out, the two element filters are much more expensive and in
this case there is a quality difference. It would be presumptious of me
to state you should go for a Nikon or Canon dual element when a single
may fit your needs.

JD
 
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Paul Rubin
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      01-02-2007
Tony Belding <(E-Mail Removed)> writes:
> Just wondering if somebody could help me sort out the pluses and
> minuses of a real (i.e. expensive) macro lens, as compared with the
> close-up lenses that thread on like a filter?


Two issues: 1) image quality; 2) convenience. For those ebay shots
(low resolution web pics that are just supposed to let the buyer see
the object you are selling) you can generally get away with pretty
lousy quality by the standards of this hyper-fussy newsgroup, and
single element diopters are likely to be fine. Convenience in the
form of not having to continually attach and remove the close-up
filter, put it someplace you won't lose it when not in use, etc. is
maybe more significant if you're using the lens a lot.

I think most ebay shots don't need extreme close-ups. There are lots
of point and digicams that will focus down to a few inches and if it
were me I'd probably use one instead of a DSLR.

The new Nikon 18-55 AFS II (the kit lens for the D40) is pretty cheap
and will focus close enough to mostly fill a frame with a wristwatch:

http://kenrockwell.com/nikon/18-55-ii.htm#macro

It might be a reasonable general purpose choice.
 
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Joseph Meehan
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      01-02-2007
Floyd L. Davidson wrote:
...
>
>> Don't use the tele, use it (them) on the 50 mm.

>
> No, it's the other way around. Closeup lenses have significantly
> more effect when used in front of a *longer* lense. There will be
> only slight difference with a 50mm lense compared to the effect using
> a 135mm lense, for example.
>
>> You may need
>> more than one if you will be photographing a range of sizes.

>
> But note that quality will suffer.


My suggestion was made based on the fact that most "normal" (50mm)
lenses will produce a sharper image than the typical 135 mm lens producing
the same image size. In addition I was also assuming that the camera would
be a digital and most likely would have a less than full size sensor,
meaning it would allow a more comfortable working distance than a full frame
film camera.

As for "Closeup lenses have significantly more effect when used in front
of a *longer* lense:" "more" is not always better. For the needs of the OP,
I would guess the potential for greater magnification when using longer
lenses is not likely to be useful. For the nature photographer, then the
added working distance and possible additional magnification could be of
value.

Maybe I should have made my reasons for my recommendations more clear.
Thanks for the opportunity to do just that.


--
Joseph Meehan

Dia 's Muire duit



 
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