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Since: Jan 06, 2008
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(Msg. 31) Posted: Mon Apr 28, 2008 10:26 pm
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
Archived from groups: rec>photo>digital (more info?)
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Jürgen Exner wrote:
> Eric Smith <eric.TakeThisOut@brouhaha.com> wrote:
>> Paul Furman <paul-.TakeThisOut@-edgehill.net> writes:
>>> On the other hand, how much detail do you need?
>> I'd like to resolve details with a minimum feature size of 3 microns.
>
> Defininately use a microscope with a camera adapter.
>
> jue
He does NOT need a microscope ... only a microscope objective
and some way to focus it.
As to focusing a microscope objective: the manufacturer specifies the
back focus ... that is, the distance from the mounting screw to were the
focal plane of the camera is. You just make sure that that distance is
about right, like within 5 mm. Then you focus by moving the subject, or
by small movement of the objective.
Doug McDonald |
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Since: Mar 28, 2008
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(Msg. 32) Posted: Mon Apr 28, 2008 11:37 pm
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
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On Sun, 27 Apr 2008 16:54:31 -0700, Eric Smith <eric.TakeThisOut@brouhaha.com>
wrote:
>I'm considering buying a Canon Digital Rebel XSi for a project involving
>macro photography, and I'm looking for advice regarding macro lenses,
>reverse mounts, etc.
>
>Basically I'm trying to photograph a flat subject such that an area
>about 1 mm on a side will be full-frame. It would be better yet if
>I could do that for an area 0.5 mm on a side.
>
>The camera has an APS-C size sensor (22.2 x 14.8 mm).
>
>I have a precision X-Y stage with stepper motors and microstepping
>control, so I can position the subject in increments of less than
>0.1 mm. I plan to take many photos with a small shift, and stitch them
>together, probably using Hugin. Because I expect there to be a lot of
>overlap between the images, I think I can tolerate some amount of
>vignetting, spherical abberation, etc.
>
>Is this feasible with some macro lens, combination of lenses, reversing
>ring, extension tube, etc?
>
>I'm hoping to avoid the need to buy a microscope and adapter, due to
>the cost, though that's obviously an option. I'm not sure how to tell
>whether a particular microscope would be suitable without trying it;
>for instance, I've looked at a 7x-90x microscope, but apparently 10x
>or 20x of that magnification is due to the magnification of the
>eyepiece, which I wouldn't have with the camera adapter.
If I understand correctly, you need a magnification of around 10 to
20. By this I mean that the image size on the sensor of the camera is
10 to 20 times as big as what you are shooting.
I agree with some other posters that your best solution might be a
microscope.
You should also be able to achieve this by reversing an ordinary Canon
lens. A little background first... Lenses are designed to work best at
particular subject and lens extension distances... normally the
optimal subject distance is from infinity to around 10 times the focal
length, and this corresponds to a lens to sensor distance of
approximately the focal length plus a couple of millimeters.
To use an example, consider a "normal lens", which would be about 35mm
focal length for the Excess Eye (XSi). Depending in which lens
exactly, it will work great focused from infinity to about 300 mm from
the lens.
If you try to get closer by using extension rings, you will be able to
focus closer, but the optical quality starts to deteriorate a bit.
When you get so close that you are near 1:1 (image and subject about
the same size), image quality is worse, and continues to get worse as
you go greater than 1. To some extent you can manage by stopping down,
but that is of limited use.
The fix is to reverse the lens when you need to shoot well over 1:1.
Then the lens becomes happy again because its distances once again are
close to its ideal distances... except that everything is in reverse.
Thus the distance from the back of the lens to the subject is now
about the same as lens-sensor when shooting at normal distances, and
the distance from the front of the lens to the sensor is now around
300 mm or greater, which is about right for this lens. The light rays
don't mind going backwards.
To give some examples ---
You are shooting a pair of shoes or whatever with the lens mounted
normally. The distance to the subject is 400 mm. With that distance,
the magnification on the sensor will be m = 0.1, and the lens
extension is 3.4mm... so the distance from the center of the lens to
the sensor is 35 + 3.4 = 38.4 mm.
Now you reverse the lens using a reverse adapter, and shoot something
very tiny. The lens-subject distance is very close at 38mm, the
lens-sensor is racked out to 420 mm, and the magnification is now
11:1. The size of the subject will be about 2 mm. The numbers are
similar to above but reversed. Image quality should be great.
But depth of field will be very shallow, about 0.5 mm according to my
calculations. And lighting the subject will be tricky.
I'm guessing you will find it easier to use a microscope for this kind
of application, but reversing the lens is a cheap and potentially good
way to do it.
Archibald |
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(Msg. 33) Posted: Tue Apr 29, 2008 1:06 am
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
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On Mon, 28 Apr 2008 19:41:18 -0800, floyd.DeleteThis@apaflo.com (Floyd L.
Davidson) wrote:
>The feature you'll want to look for is the ability to
>mount it in a way that you can use your X-Y stage (which
>is not true of all metallurgical scopes). Another
>feature, which is almost universal though there is a
>chance you don't need it, is episcopic (or "epi" for
>short) illumination. That uses a beam splitter to
>illuminate the object through the same optical path that
>you view it. (That is probably _very_ useful to you.)
Floyd, I was a dealer for Zeiss microscopes for 30 years. I've been
to the Zeiss facilities in Germany. I've sold hundreds of microscopes
and beam splitters. The beam splitter splits the optical path. It's
used to provide a view for a second observer or for photography. The
field of view is illuminated coaxially with the prime viewer
completely independent of the beam splitter. The observer or camera
is seeing the same field of view as the prime viewer, and that field
is illuminated.
The prefix "epi" means "above". There are two types of episcopes:
one projects light from above for surface viewing, and the second -
and the most common use of "episcope" - is a device that projects an
image using a mirror.
An overhead projector is an episcope. The kind most of us are
familiar with, though, is:
http://www.stds.fr/boutique/images_produits/vAT01-AR225-481.jpg When
we were kids, we used these to project an image - usually the comic
pages - on a piece of paper taped to the wall - so we could trace over
it.
>Microscopes can be very expensive, but it is unlikely
>that you need a fancy one. It should be fairly easy to
>find an older used model that will do fine. They often
>are available on eBay at reasonable prices, as are the
>parts and pieces such as objectives and "relay lenses"
>for photography. Keep in mind that objective lenses are
>matched to the eye pieces (and to the relay lenses used
>for projecting into a camera), and hence should not
>necessarily be mixed and matched between manufacturers.
I can't figure out what you're saying here, and I'm pretty familiar
with microscopes. I have no idea what "relay lenses" are. There are
two ways to photograph through a microscope: (1) You attach a camera
body to a port of the beam splitter. (2) You attach a camera body in
place of an eyepiece. Some microscopes have built-in beam splitters
with a single port, and some use a beam splitter that goes between the
microscope body and the binoculars.
I don't know what you mean by matching objective lenses to eyepieces.
Naturally you have to have compatibility of manufacturer, but a
microscope can be set up with several combinations of objective lenses
and eyepieces. The combination determines the viewer's magnification
and the field of view.
I haven't been able to figure out, from the postings I've read, if he
even really needs a camera body. There are systems available that
send the image direct to a computer, and the computer captures the
image.
He might be able to work with an instrument like the digital boom
microscope at
http://www.microscope.com/omano-ezvuv7-digital-articulated-zoom-boom-m...oscope-
because it doesn't appear that he needs to view the field through
eyepieces at all. This would provide 7x to 45x magnification, or up
to 90x with the Barlow lens. It could swing over his stage.
I have no idea about the re-sale aspect of this type of instrument,
but he could check with the company and see if an arrangement could be
made. They may buy back the instrument at an agreed-on price if they
can re-sell it.
While $1,700 seems like it's over his budget, he'd might be spending
$1,000 on a camera system with macro accessories that doesn't do what
he wants done.
--
Tony Cooper - Orlando, Florida >> Stay informed about: Newbie question about macro with DSLR |
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Since: Mar 28, 2008
Posts: 13
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(Msg. 34) Posted: Tue Apr 29, 2008 1:17 am
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)
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On Mon, 28 Apr 2008 23:37:54 GMT, Archibald <Archibald RemoveThis @spamhater.com>
wrote:
>On Sun, 27 Apr 2008 16:54:31 -0700, Eric Smith <eric RemoveThis @brouhaha.com>
>wrote:
>
>>I'm considering buying a Canon Digital Rebel XSi for a project involving
>>macro photography, and I'm looking for advice regarding macro lenses,
>>reverse mounts, etc.
>>
>>Basically I'm trying to photograph a flat subject such that an area
>>about 1 mm on a side will be full-frame. It would be better yet if
>>I could do that for an area 0.5 mm on a side.
>>
>>The camera has an APS-C size sensor (22.2 x 14.8 mm).
>>
>>I have a precision X-Y stage with stepper motors and microstepping
>>control, so I can position the subject in increments of less than
>>0.1 mm. I plan to take many photos with a small shift, and stitch them
>>together, probably using Hugin. Because I expect there to be a lot of
>>overlap between the images, I think I can tolerate some amount of
>>vignetting, spherical abberation, etc.
>>
>>Is this feasible with some macro lens, combination of lenses, reversing
>>ring, extension tube, etc?
>>
>>I'm hoping to avoid the need to buy a microscope and adapter, due to
>>the cost, though that's obviously an option. I'm not sure how to tell
>>whether a particular microscope would be suitable without trying it;
>>for instance, I've looked at a 7x-90x microscope, but apparently 10x
>>or 20x of that magnification is due to the magnification of the
>>eyepiece, which I wouldn't have with the camera adapter.
>
>If I understand correctly, you need a magnification of around 10 to
>20. By this I mean that the image size on the sensor of the camera is
>10 to 20 times as big as what you are shooting.
>
>I agree with some other posters that your best solution might be a
>microscope.
>
>You should also be able to achieve this by reversing an ordinary Canon
>lens. A little background first... Lenses are designed to work best at
>particular subject and lens extension distances... normally the
>optimal subject distance is from infinity to around 10 times the focal
>length, and this corresponds to a lens to sensor distance of
>approximately the focal length plus a couple of millimeters.
>
>To use an example, consider a "normal lens", which would be about 35mm
>focal length for the Excess Eye (XSi). Depending in which lens
>exactly, it will work great focused from infinity to about 300 mm from
>the lens.
>
>If you try to get closer by using extension rings, you will be able to
>focus closer, but the optical quality starts to deteriorate a bit.
>When you get so close that you are near 1:1 (image and subject about
>the same size), image quality is worse, and continues to get worse as
>you go greater than 1. To some extent you can manage by stopping down,
>but that is of limited use.
>
>The fix is to reverse the lens when you need to shoot well over 1:1.
>Then the lens becomes happy again because its distances once again are
>close to its ideal distances... except that everything is in reverse.
>Thus the distance from the back of the lens to the subject is now
>about the same as lens-sensor when shooting at normal distances, and
>the distance from the front of the lens to the sensor is now around
>300 mm or greater, which is about right for this lens. The light rays
>don't mind going backwards.
>
>To give some examples ---
>
>You are shooting a pair of shoes or whatever with the lens mounted
>normally. The distance to the subject is 400 mm. With that distance,
>the magnification on the sensor will be m = 0.1, and the lens
>extension is 3.4mm... so the distance from the center of the lens to
>the sensor is 35 + 3.4 = 38.4 mm.
>
>Now you reverse the lens using a reverse adapter, and shoot something
>very tiny. The lens-subject distance is very close at 38mm, the
>lens-sensor is racked out to 420 mm, and the magnification is now
>11:1. The size of the subject will be about 2 mm. The numbers are
>similar to above but reversed. Image quality should be great.
>
>But depth of field will be very shallow, about 0.5 mm according to my
>calculations. And lighting the subject will be tricky.
>
>I'm guessing you will find it easier to use a microscope for this kind
>of application, but reversing the lens is a cheap and potentially good
>way to do it.
>
>Archibald
Here's a link to a web site of someone who has adapted a bellows to a
Canon for macrophotography -- check out the link at the bottom too.
http://www.ganymeta.org/~darren/photo_bellows.php
Archibald >> Stay informed about: Newbie question about macro with DSLR |
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Posts: 147
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(Msg. 35) Posted: Tue Apr 29, 2008 1:24 am
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
Archived from groups: per prev. post (more info?)
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On Mon, 28 Apr 2008 20:21:15 -0800, floyd.RemoveThis@apaflo.com (Floyd L.
Davidson) wrote:
>user@domain.invalid wrote:
>>Jürgen Exner wrote:
>>> Eric Smith <eric.RemoveThis@brouhaha.com> wrote:
>>>> Paul Furman <paul-.RemoveThis@-edgehill.net> writes:
>>>>> On the other hand, how much detail do you need?
>>>> I'd like to resolve details with a minimum feature size of 3 microns.
>>> Defininately use a microscope with a camera adapter.
>>> jue
>>
>>He does NOT need a microscope ... only a microscope objective
>>and some way to focus it.
>
>He needs a microscope. In addition to the objective and
>focusing mechanism , he needs a "projection" (aka
>"relay") lense appropriate for the sensor size.
I'm still trying to figure out what you mean by a "relay lens".
Projection is done with a prism and not with a lens. A beam splitter
projects the optical view by bending it with the prism. The type of
prism, and the distance between the prism and the sensor, determines
what the sensor records.
>One additional feature that would be nice is episcopic
>illumination.
OK, I figured this out. You are evidently talking about light
projected from above the field as opposed to light projected from
below the field. I have no idea why you want to call it "episcopic",
though. "From above" works fine.
Some lab microscopes have illuminated stages (light from below) so the
light illuminates the material on the slide. Some have light
projected down to the stage from either a coaxial system or fiber
optic ring light. Some use both.
If his object - the thing he's photographing - is opaque, he *must*
have light from above. Not "nice", but essential.
--
Tony Cooper - Orlando, Florida >> Stay informed about: Newbie question about macro with DSLR |
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Since: Aug 21, 2006
Posts: 150
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(Msg. 36) Posted: Tue Apr 29, 2008 6:57 am
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
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tony cooper wrote:
>
>> Microscopes can be very expensive, but it is unlikely
>> that you need a fancy one. It should be fairly easy to
>> find an older used model that will do fine. They often
>> are available on eBay at reasonable prices, as are the
>> parts and pieces such as objectives and "relay lenses"
>> for photography. Keep in mind that objective lenses are
>> matched to the eye pieces (and to the relay lenses used
>> for projecting into a camera), and hence should not
>> necessarily be mixed and matched between manufacturers.
>
> I can't figure out what you're saying here, and I'm pretty familiar
> with microscopes. I have no idea what "relay lenses" are.
They are what the words say. I own a late 1990's inverted Zeiss Axiovert
microscope, a top of the line gizmo. The objective sends the light,
COLLIMATED, through an optional beamsplitter used for epi-fluorescence.
This beamsplitter lets the fluorescence through, and reflects the light that
comes IN to excite the fluorescence. It also contains transmission
filters for the incoming and outgoing light. It is optional, and
is not used for brightfield illumination. This is not a metallographic
microscope and does not have darkfield.
The light then continues downward through a "tube lens". This is a lens
of 163 mm focal length that focus the collimated light. The light then
goes out the bottom of the scope onto a TV camera. There is a mirror that
slides into this path and reflects the light up toward the eyepiece.
But it focuses too soon, so there is a field lens near the focus,
and, farther on, a set of relay lenses that image the first virtual
image, at the field lens, up into the eyepiece assembly. That's what
a relay lens is used for.
Because Zeiss now uses "tube lenses", an objective from my scope would
not, by itself, work properly as a camera lens. You would need the specific
Zeiss "tube lens".
Different companies (i.e. at least the big three, Nikon, Zeiss, and
Olympus) make different tube lenses. They are part of the aberration
correction system and using the wrong one will result in lateral
chromatic aberration. Olympus used to sell ... maybe still does,
and you certainly can get used, objectives that do NOT need a tube lens,
instead doing all the focusing themselves. Some of these, unfortunately,
don't correct the later chromatic, instead leaving that to the eyepiece.
However, many of them (or rather did). Any one that was intended
for photography without a tube lens did.
Doug McDonald >> Stay informed about: Newbie question about macro with DSLR |
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Posts: 203
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(Msg. 37) Posted: Tue Apr 29, 2008 7:40 am
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
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"Jürgen Exner" <jurgenex DeleteThis @hotmail.com> wrote in message
news:acjc14ppic294iiu7mqlmnl38ao8jrlq6p@4ax.com...
....
>
> Yeah, for whatever reason Nikon calls "Micro" what everyone else calls
> "Macro".
>
Yea. Frankly everyone else is wrong, :-0 Well Nikon is wrong in their
use from time to time as well. I don't think it is going to get
straightened out, but it is good to keep in mind that there are two terms
and that we should all expect them to be used properly and improperly so we
don't assume that they will be used in the manner we expect.
--
Joseph Meehan
Dia 's Muire duit >> Stay informed about: Newbie question about macro with DSLR |
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(Msg. 38) Posted: Tue Apr 29, 2008 5:56 pm
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
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(Msg. 39) Posted: Tue Apr 29, 2008 5:58 pm
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
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Doug McDonald wrote:
> What are you going to photograph?
PMOS integrated circuits fabricated between 1975 and 1978.
Minimum feature size (as drawn) is at least 3 microns.
> Remember that lenses are available at 20x magnification that will
> resolve .5 micron ... that is, 1000 line pairs per mm.
Really? Can you point me to any specific models?
Thanks!
Eric >> Stay informed about: Newbie question about macro with DSLR |
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(Msg. 40) Posted: Tue Apr 29, 2008 6:00 pm
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
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(Msg. 41) Posted: Tue Apr 29, 2008 6:07 pm
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
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Floyd L. Davidson wrote:
> You need a microscope.
I suppose you're probably right. I was hoping some other, less
expensive possibilities, like a Raynox MSN-505 or CM-3500 conversion
lens used with a telephoto lens might do the trick. I can probably
find other uses for the conversion lenses anyhow, so I don't mind
buying them even if they don't work out for my current project.
> Do you want _each_ image to be even higher magnification
> than stated above, and for the resulting final product
> to be as described above???? Or do you mean each
> exposure will capture 0.5 to 1.0 mm of a larger object?
The overall size of the subject is under 10mm on a side. I wanted
to get shots of 0.5 to 1.0 mm square portions of that, then stitch
them together.
> If you mean that each exposure will capture 1mm of an
> object, then a typical dissecting microscope would be
> appropriate (and would be very convenient to mate with
> your X-Y state). Another possibility is a toolmakers
> metallurgical microscope.
OK, I'll look into those.
> The feature you'll want to look for is the ability to
> mount it in a way that you can use your X-Y stage (which
> is not true of all metallurgical scopes).
Some of the relatively inexpensive microscopes I've looked
at have a single-boom or double-boom mount that should do
that. I'm not sure which would be better for stability
(vibration).
> Another feature, which is almost universal though there is a
> chance you don't need it, is episcopic (or "epi" for
> short) illumination. That uses a beam splitter to
> illuminate the object through the same optical path that
> you view it. (That is probably _very_ useful to you.)
Definitely. I hadn't even heard of it. The microscopes
I've looked at have ring illuminators, which obviously
wouldn't be useful if the objective has to be very close
to the subject.
Thanks for all the advice!
Eric >> Stay informed about: Newbie question about macro with DSLR |
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(Msg. 42) Posted: Wed Apr 30, 2008 8:39 am
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
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Eric Smith wrote:
> Doug McDonald wrote:
>> What are you going to photograph?
>
> PMOS integrated circuits fabricated between 1975 and 1978.
> Minimum feature size (as drawn) is at least 3 microns.
>
>> Remember that lenses are available at 20x magnification that will
>> resolve .5 micron ... that is, 1000 line pairs per mm.
>
> Really? Can you point me to any specific models?
>
> Thanks!
> Eric
Unfortunately, not usefully. I can point to plenty of ones
that need a tube lens, but not ones that don't. They do exist.
Remember this: resolving power is determined by "numerical aperture",
N. A.
f/number = 1 / (2 * N. A.) (for lenses working in air)
In other words an N. A. 1.0 lens is f/0.5
0.5 lens is f/1.0
0.3 lens is f/1.6
etc.
resolving power, defined as the half-width of the blur function at the
subject, is roughly f/number, in microns.
In other words, the blur of an N. A. 0.5 objective is about 1 micron.
This is fairly rough, formally it is actually 0.83 microns.
You don't need a big-name objective to get the job done.
Google on "microscope objectives". You need a "plan" one (i.e. flat field) for "no tube lens"
or NOT "infinite focus" and also if it matters for that objective, NO COVER GLASS.
Also, you need to worry about working distance if you intend to send light in from the side.
I found many objectives that will work under $150 ... but I didn't check to see
if they will work well with no cover glass.
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(Msg. 43) Posted: Wed Apr 30, 2008 9:44 am
Post subject: Re: Newbie question about macro with DSLR [Login to view extended thread Info.]
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user.TakeThisOut@domain.invalid wrote:
>Eric Smith wrote:
>> Doug McDonald wrote:
>>> What are you going to photograph?
>> PMOS integrated circuits fabricated between 1975 and
>> 1978.
>> Minimum feature size (as drawn) is at least 3 microns.
>>
>>> Remember that lenses are available at 20x magnification that will
>>> resolve .5 micron ... that is, 1000 line pairs per mm.
>> Really? Can you point me to any specific models?
>> Thanks!
>> Eric
>
>Unfortunately, not usefully. I can point to plenty of ones
>that need a tube lens, but not ones that don't. They do exist.
>
>Remember this: resolving power is determined by "numerical aperture",
>N. A.
>
>f/number = 1 / (2 * N. A.) (for lenses working in air)
>
>In other words an N. A. 1.0 lens is f/0.5
> 0.5 lens is f/1.0
> 0.3 lens is f/1.6
> etc.
>
>resolving power, defined as the half-width of the blur function at the
>subject, is roughly f/number, in microns.
>
>In other words, the blur of an N. A. 0.5 objective is about 1 micron.
>This is fairly rough, formally it is actually 0.83 microns.
>
>You don't need a big-name objective to get the job done.
>
>Google on "microscope objectives". You need a "plan" one (i.e. flat field) for "no tube lens"
>or NOT "infinite focus" and also if it matters for that objective, NO COVER GLASS.
>
>Also, you need to worry about working distance if you intend to send light in from the side.
Objectives for metallurgical work are the ones which fit
the description. They have longer working distances and
are intended for use with no cover glass. Typically
there will be an "M", "N", or "E" in the model number.
Zeiss might label something as "EpiPlan".
A typical description would look like this:
40x/0.70 160/-
The 40x indicates the magnification when used as a
microscope, the 0.70 is the N.A. value as discussed
above (indicating the aperture), the 160 is the tube
length it was designed for (avoid any listed as "inf"),
and the "-" indicates that is it designed to be used
without a slip cover (otherwise a number, such as ".17"
would be listed, and indicates the thickness of the slip
cover).
The problem that I'd wonder about is that typically the
objective and the ocular or projection lenses are
matched pairs with aberrrations compensated partially in
each. Apparently Nikon may not do that, and therefore
might be the best choice of manufacturer, but I have
never been able to positively confirm that. I've never
seen any numbers for Unitron either, though the
nomenclature they use for oculars would indicate
compensation too.
Typically available objectives that might meet Eric's
needs are:
10X:
Leitz 10x/0.25 170/-
Nikon E Plan 10x/0.25 160/-
Olympus Neo 10x/0.25 200/
Unitron MF (Plan Acro) 10x/0.25
Unitron MPL 10x/0.25
Zeiss NPL Fluotar 10x/0.30 160/-
20X:
Olympus NeoPlan 20x/0.40
Unitron MF (Plan Acro) 20x/0.40
Unitron MPL 20x/0.40
Unitron M 20x/0.45
40X:
Unitron Epi MF (Plan Acro) 40x/0.65 170
Unitron MPl 40x/0.65 170/-
Unitron M Plan 40x/0.65 170/-
Unitron M Acro 40x/0.65 170/-
Zeiss EpiPlan-HD 40x/0.85 160/0
Olympus and Unitron objectives are very common and
usually relatively inexpensive. Nikon and Zeiss seem to
run hot and cold on prices. Regardless, it should be
possible to come up with a representative example for
less than $100 that is at least useful for testing. If
it is worth the difference, there are certainly a number
of objectives that cost several hundreds of dollars.
--
Floyd L. Davidson <http://www.apaflo.com/floyd_davidson>
Ukpeagvik (Barrow, Alaska) floyd.TakeThisOut@apaflo.com >> Stay informed about: Newbie question about macro with DSLR |
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