Is it possible to buy a scale to put on the slide in order to measure the
image? My eyepieces don't look as if they will support a reticle. I suppose
the problem with putting a scale on the slide might be that at high
magnification the scale and the object won't be in focus at the same time.
Can any of you offer any advice on this matter? I'm wanting to identify
mosses and it appears that I need to be able to measure the cells.

Peter

From:	Andy Resnick
Subject:	Re: Calibration
Date:	Tue, 28 Dec 2004 14:39:35 -0500

Peter Bovey wrote:

>Is it possible to buy a scale to put on the slide in order to measure the
>image? My eyepieces don't look as if they will support a reticle. I suppose
>the problem with putting a scale on the slide might be that at high
>magnification the scale and the object won't be in focus at the same time.
>Can any of you offer any advice on this matter? I'm wanting to identify
>mosses and it appears that I need to be able to measure the cells.
>
>Peter
>
Peter,

It's not clear from your post if you need to have a reticle/graticule in
the eyepiece, or some way of having length information on a camera
image. For the reticle, you could probably figure out a way of putting
one either in the eyepiece, or down the cylinder into where the eyepiece
slides- in that case, you need a known object to calibrate the reticle
to give length information. Edmund scientific carries a bunch and they
are cheap. The easiest thing is to call Prior and ask them what size
reticle is required and where it needs to go.

If, on the other hand, you are acquiring images and need to convert
pixels into microns (or some such thing), you need an image of a
calibrated ruling. Rulings can be cheap or expensive, depending on the
exactitude you need. Again, Edmund carries cheap ones.

--
Andrew Resnick, Ph.D.
Department of Physiology and Biophysics
CWRU School of Medicine
tanspose 'op' for mail

From:	Kristian Ukkonen
Subject:	Re: Calibration
Date:	Tue, 28 Dec 2004 20:00:12 GMT

Andy Resnick wrote:
> If, on the other hand, you are acquiring images and need to convert
> pixels into microns (or some such thing), you need an image of a
> calibrated ruling. Rulings can be cheap or expensive, depending on the
> exactitude you need. Again, Edmund carries cheap ones.

Out of curiosity, if you happen to know of these systems.

When you have a PC+camera+microscope, and calibrate the measurement
(for example, distance from point A to point B in image of camera
at PC software) with a calibrated ruling. When "nothing" changes
(same microscope, objectives etc.), how often do you re-calibrate - or
is the calibration ok for 10+ years? Any explanation for the period
or lack of need of recalibration?

For most electrical measurement devices, you recalibrate every
year or whatever, and the accuracy is stated as "A% for 24hours,
B% for 1month, C% for 1 year from calibration date". It seems there
is no similar statement of accurace of measurements for microscopes..

Best regards,

Kristian Ukkonen.

From:	Andy Resnick
Subject:	Re: Calibration
Date:	Wed, 29 Dec 2004 09:03:44 -0500

Kristian Ukkonen wrote:

>
> Andy Resnick wrote:
>
>> If, on the other hand, you are acquiring images and need to convert
>> pixels into microns (or some such thing), you need an image of a
>> calibrated ruling. Rulings can be cheap or expensive, depending on
>> the exactitude you need. Again, Edmund carries cheap ones.
>
>
> Out of curiosity, if you happen to know of these systems.
>
> When you have a PC+camera+microscope, and calibrate the measurement
> (for example, distance from point A to point B in image of camera
> at PC software) with a calibrated ruling. When "nothing" changes
> (same microscope, objectives etc.), how often do you re-calibrate - or
> is the calibration ok for 10+ years? Any explanation for the period
> or lack of need of recalibration?
>
> For most electrical measurement devices, you recalibrate every
> year or whatever, and the accuracy is stated as "A% for 24hours,
> B% for 1month, C% for 1 year from calibration date". It seems there
> is no similar statement of accurace of measurements for microscopes..

Interesting question.

Let's also assume the camera and PC are constants. I think that the main
source of error in this case is the user. Since the image will have
some blur, which pixel the user decides is the edge of the micrometer
bar is the source of some variation. Also, there will be some variation
due to non-perfect alignment of the micrometer to the pixel array in the
camera. After that, I would think there are small errors introduced due
to temperature fluctuations (thermal expansion of the micrometer, slight
changes in the optical path due to thermal expansion of the lenses in
the objectives, etc.

Aside from things like bulb output, camera electronics and motorized
stage wear and tear, there probably are sources of long-term drift in a
microscope, but I don't know what they are.

Personally, I rarely re-calibrate. Mostly, it's because our work
doesn't require extremely high levels of precision. If a particular
experiment calls for high precision, I'll take a few "calibration"
images just prior to and just after the experiment as a 'best practice'.

Are you asking for a reason, or idle curiosity?

--
Andrew Resnick, Ph.D.
Department of Physiology and Biophysics
CWRU School of Medicine
tanspose 'op' for mail

From:	Peter Bovey
Subject:	Re: Calibration
Date:	Wed, 29 Dec 2004 14:20:16 GMT

"Kristian Ukkonen" wrote in message
news:gXiAd.837$Hm4.239@read3.inet.fi...
>
> Andy Resnick wrote:
>> If, on the other hand, you are acquiring images and need to convert
>> pixels into microns (or some such thing), you need an image of a
>> calibrated ruling. Rulings can be cheap or expensive, depending on the
>> exactitude you need. Again, Edmund carries cheap ones.
>
> Out of curiosity, if you happen to know of these systems.
>
> When you have a PC+camera+microscope, and calibrate the measurement
> (for example, distance from point A to point B in image of camera
> at PC software) with a calibrated ruling. When "nothing" changes
> (same microscope, objectives etc.), how often do you re-calibrate - or is
> the calibration ok for 10+ years? Any explanation for the period
> or lack of need of recalibration?
>
> For most electrical measurement devices, you recalibrate every
> year or whatever, and the accuracy is stated as "A% for 24hours,
> B% for 1month, C% for 1 year from calibration date". It seems there
> is no similar statement of accurace of measurements for microscopes..
>
> Best regards,
>
> Kristian Ukkonen.
>
Thanks Kristian, but that is all rather out of my league. I'm just an
amateur botanist wanting to measure, with a manual microscope, approximate
cell sizes in mucrons.
Thanks anyway,
Peter

From:	Peter Bovey
Subject:	Re: Calibration
Date:	Wed, 29 Dec 2004 14:42:50 GMT

"Peter Bovey" wrote in message
news:A2zAd.505$1c.284@text.news.blueyonder.co.uk...
>
> "Kristian Ukkonen" wrote in message
> news:gXiAd.837$Hm4.239@read3.inet.fi...
>>
>> Andy Resnick wrote:
>>> If, on the other hand, you are acquiring images and need to convert
>>> pixels into microns (or some such thing), you need an image of a
>>> calibrated ruling. Rulings can be cheap or expensive, depending on the
>>> exactitude you need. Again, Edmund carries cheap ones.
>>
>> Out of curiosity, if you happen to know of these systems.
>>
>> When you have a PC+camera+microscope, and calibrate the measurement
>> (for example, distance from point A to point B in image of camera
>> at PC software) with a calibrated ruling. When "nothing" changes
>> (same microscope, objectives etc.), how often do you re-calibrate - or is
>> the calibration ok for 10+ years? Any explanation for the period
>> or lack of need of recalibration?
>>
>> For most electrical measurement devices, you recalibrate every
>> year or whatever, and the accuracy is stated as "A% for 24hours,
>> B% for 1month, C% for 1 year from calibration date". It seems there
>> is no similar statement of accurace of measurements for microscopes..
>>
>> Best regards,
>>
>> Kristian Ukkonen.
>>
> Thanks Kristian, but that is all rather out of my league. I'm just an
> amateur botanist wanting to measure, with a manual microscope, approximate
> cell sizes in mucrons.
> Thanks anyway,
> Peter
Sorry, meant 'microns' :-)

From:	Kevin Cunningham
Subject:	Re: Calibration
Date:	Wed, 29 Dec 2004 00:08:28 GMT

"Kristian Ukkonen" wrote in message
news:gXiAd.837$Hm4.239@read3.inet.fi...
>
> Andy Resnick wrote:
>> If, on the other hand, you are acquiring images and need to convert
>> pixels into microns (or some such thing), you need an image of a
>> calibrated ruling. Rulings can be cheap or expensive, depending on the
>> exactitude you need. Again, Edmund carries cheap ones.
>
> Out of curiosity, if you happen to know of these systems.
>
> When you have a PC+camera+microscope, and calibrate the measurement
> (for example, distance from point A to point B in image of camera
> at PC software) with a calibrated ruling. When "nothing" changes
> (same microscope, objectives etc.), how often do you re-calibrate - or is
> the calibration ok for 10+ years? Any explanation for the period
> or lack of need of recalibration?
>
> For most electrical measurement devices, you recalibrate every
> year or whatever, and the accuracy is stated as "A% for 24hours,
> B% for 1month, C% for 1 year from calibration date". It seems there
> is no similar statement of accurace of measurements for microscopes..
>
> Best regards,
>
> Kristian Ukkonen.
>
Kristian, In my experience once in the microscopes life time is adequate.
Glass doesn't change enough to affect a reticle. Microscope reticles will
be inaccurate by a few percent, far more than than changes in the glass. Of
all of the methods of measurement reticles are the worst. However they are
more than enough for biological measurements since biological stuff will
just vary. If you need more accurate measurement there are all sorts of
electronic things that work well.

Kevin Cunningham

From:	Kristian Ukkonen
Subject:	Re: Calibration
Date:	Wed, 29 Dec 2004 13:12:24 GMT

Kevin Cunningham wrote:
> "Kristian Ukkonen" wrote in message
>>When you have a PC+camera+microscope, and calibrate the measurement
>>(for example, distance from point A to point B in image of camera
>>at PC software) with a calibrated ruling. When "nothing" changes
>>(same microscope, objectives etc.), how often do you re-calibrate - or is
>>the calibration ok for 10+ years? Any explanation for the period
>>or lack of need of recalibration?
>>
>>For most electrical measurement devices, you recalibrate every
>>year or whatever, and the accuracy is stated as "A% for 24hours,
>>B% for 1month, C% for 1 year from calibration date". It seems there
>>is no similar statement of accurace of measurements for microscopes..
>
> Kristian, In my experience once in the microscopes life time is adequate.
> Glass doesn't change enough to affect a reticle. Microscope reticles will
> be inaccurate by a few percent, far more than than changes in the glass. Of
> all of the methods of measurement reticles are the worst. However they are
> more than enough for biological measurements since biological stuff will
> just vary. If you need more accurate measurement there are all sorts of
> electronic things that work well.

I was not referring to reticles, but a PC software that
shows the image from camera, and calculates distance
based on calibration (based on image of calibrated ruler).
This was indeed a question regarding "electrical things". :)
Is it usual in these kinds of systems that calibration is
done only once, like in reticle-based systems you mention
above in your reply?

Kristian Ukkonen.

From:	Peter Bovey
Subject:	Re: Calibration
Date:	Wed, 29 Dec 2004 14:15:21 GMT

"Andy Resnick" wrote in message
news:cqscpi$9r0$1@eeyore.INS.cwru.edu...
> Peter Bovey wrote:
>
>>Is it possible to buy a scale to put on the slide in order to measure the
>>image? My eyepieces don't look as if they will support a reticle. I
>>suppose the problem with putting a scale on the slide might be that at
>>high magnification the scale and the object won't be in focus at the same
>>time. Can any of you offer any advice on this matter? I'm wanting to
>>identify mosses and it appears that I need to be able to measure the
>>cells.
>>
>>Peter
> Peter,
>
> It's not clear from your post if you need to have a reticle/graticule in
> the eyepiece, or some way of having length information on a camera image.
> For the reticle, you could probably figure out a way of putting one either
> in the eyepiece, or down the cylinder into where the eyepiece slides- in
> that case, you need a known object to calibrate the reticle to give length
> information. Edmund scientific carries a bunch and they are cheap. The
> easiest thing is to call Prior and ask them what size reticle is required
> and where it needs to go.
>
> If, on the other hand, you are acquiring images and need to convert pixels
> into microns (or some such thing), you need an image of a calibrated
> ruling. Rulings can be cheap or expensive, depending on the exactitude
> you need. Again, Edmund carries cheap ones.
>
> --
> Andrew Resnick, Ph.D.
> Department of Physiology and Biophysics
> CWRU School of Medicine
> tanspose 'op' for mail
>
Thanks Andy. I'm not interested in aquiring images at the moment. I'm going
to contact Prior and take it from there.

Peter

From:	Kevin Cunningham
Subject:	Re: Calibration
Date:	Wed, 29 Dec 2004 00:26:25 GMT

"Andy Resnick" wrote in message
news:cqscpi$9r0$1@eeyore.INS.cwru.edu...
> Peter Bovey wrote:
>
>>Is it possible to buy a scale to put on the slide in order to measure the
>>image? My eyepieces don't look as if they will support a reticle. I
>>suppose the problem with putting a scale on the slide might be that at
>>high magnification the scale and the object won't be in focus at the same
>>time. Can any of you offer any advice on this matter? I'm wanting to
>>identify mosses and it appears that I need to be able to measure the
>>cells.
>>
>>Peter
> Peter,
>
> It's not clear from your post if you need to have a reticle/graticule in
> the eyepiece, or some way of having length information on a camera image.
> For the reticle, you could probably figure out a way of putting one either
> in the eyepiece, or down the cylinder into where the eyepiece slides- in
> that case, you need a known object to calibrate the reticle to give length
> information. Edmund scientific carries a bunch and they are cheap. The
> easiest thing is to call Prior and ask them what size reticle is required
> and where it needs to go.
>
> If, on the other hand, you are acquiring images and need to convert pixels
> into microns (or some such thing), you need an image of a calibrated
> ruling. Rulings can be cheap or expensive, depending on the exactitude
> you need. Again, Edmund carries cheap ones.
>
> --
> Andrew Resnick, Ph.D.
> Department of Physiology and Biophysics
> CWRU School of Medicine
> tanspose 'op' for mail
>
Andy, Good post just a quick point. The reticle goes in the eyepiece, if
you put it down the below the eyepiece you won't see it but it won't bother
you. Depends on what you need.

Thanks,

Kevin Cunningham
SMS

From:	Kevin Cunningham
Subject:	Re: Calibration
Date:	Wed, 29 Dec 2004 00:26:27 GMT

"Andy Resnick" wrote in message
news:cqscpi$9r0$1@eeyore.INS.cwru.edu...
> Peter Bovey wrote:
>
>>Is it possible to buy a scale to put on the slide in order to measure the
>>image? My eyepieces don't look as if they will support a reticle. I
>>suppose the problem with putting a scale on the slide might be that at
>>high magnification the scale and the object won't be in focus at the same
>>time. Can any of you offer any advice on this matter? I'm wanting to
>>identify mosses and it appears that I need to be able to measure the
>>cells.
>>
>>Peter
> Peter,
>
> It's not clear from your post if you need to have a reticle/graticule in
> the eyepiece, or some way of having length information on a camera image.
> For the reticle, you could probably figure out a way of putting one either
> in the eyepiece, or down the cylinder into where the eyepiece slides- in
> that case, you need a known object to calibrate the reticle to give length
> information. Edmund scientific carries a bunch and they are cheap. The
> easiest thing is to call Prior and ask them what size reticle is required
> and where it needs to go.
>
> If, on the other hand, you are acquiring images and need to convert pixels
> into microns (or some such thing), you need an image of a calibrated
> ruling. Rulings can be cheap or expensive, depending on the exactitude
> you need. Again, Edmund carries cheap ones.
>
> --
> Andrew Resnick, Ph.D.
> Department of Physiology and Biophysics
> CWRU School of Medicine
> tanspose 'op' for mail
>
Andrew, Good post, just a small point. The reticle goes in the eyepiece not
the eyepiece tube. Put it in the tube and you'll never see it but this does
keep the reticle from bothering you.

Thanks,

Kevin Cunningham
SMS

From:	Aaron
Subject:	Re: Calibration
Date:	28 Dec 2004 21:33:04 -0600

Hi Peter,

There is a scale called a stage micrometer which can be used to
calibrate an eyepiece reticle or there are special eyepieces called
filar eyepieces that have a reticle plus a micrometer driven reference
line. Both these items come up for sale from time to time in eBay.
Both items are listed now.. The stage micrometer is used to calibrate
an eyepiece objective combination.

Please contact me off line at
nghy_1@REMOVEyahoo.com for additional information.

Aaron

See

http://www.microscopyu.com/articles/formulas/measurements.html

On Mon, 27 Dec 2004 20:46:14 GMT, "Peter Bovey"
wrote:

>Is it possible to buy a scale to put on the slide in order to measure the
>image? My eyepieces don't look as if they will support a reticle. I suppose
>the problem with putting a scale on the slide might be that at high
>magnification the scale and the object won't be in focus at the same time.
>Can any of you offer any advice on this matter? I'm wanting to identify
>mosses and it appears that I need to be able to measure the cells.
>
>Peter
>

From:	Kevin Cunningham
Subject:	Re: Calibration
Date:	Tue, 28 Dec 2004 02:37:33 GMT

"Peter Bovey" wrote in message
news:qw_zd.7858$Ar5.6741@text.news.blueyonder.co.uk...
> Is it possible to buy a scale to put on the slide in order to measure the
> image? My eyepieces don't look as if they will support a reticle. I
> suppose the problem with putting a scale on the slide might be that at
> high magnification the scale and the object won't be in focus at the same
> time. Can any of you offer any advice on this matter? I'm wanting to
> identify mosses and it appears that I need to be able to measure the
> cells.
>
> Peter
Peter, Actually you can put reticule into any eyepiece I've ever seen.
While your idea is good, using a ruling on the slide, you would have
problems with expense and dept of field.

The reticle can go on the inside of the eypiece or be held in place by a
very cheap jump ring. Let us know what kind of eyepiece you have and I can
let you know what to do. Oh, here's Klarmann Rulings, they make just about
all of the reticles (www.reticles.com)

Kevin Cunningham
SMS

From:	Peter Bovey
Subject:	Re: Calibration
Date:	Tue, 28 Dec 2004 14:23:14 GMT

>
> "Peter Bovey" wrote in message
> news:qw_zd.7858$Ar5.6741@text.news.blueyonder.co.uk...
>> Is it possible to buy a scale to put on the slide in order to measure the
>> image? My eyepieces don't look as if they will support a reticle. I
>> suppose the problem with putting a scale on the slide might be that at
>> high magnification the scale and the object won't be in focus at the same
>> time. Can any of you offer any advice on this matter? I'm wanting to
>> identify mosses and it appears that I need to be able to measure the
>> cells.

"Kevin Cunningham" wrote in message
news:NF3Ad.5138$qf5.2344@newsread3.news.atl.earthlink.net...
>> Peter
> Peter, Actually you can put reticule into any eyepiece I've ever seen.
> While your idea is good, using a ruling on the slide, you would have
> problems with expense and dept of field.
>
> The reticle can go on the inside of the eypiece or be held in place by a
> very cheap jump ring. Let us know what kind of eyepiece you have and I
> can let you know what to do. Oh, here's Klarmann Rulings, they make just
> about all of the reticles (www.reticles.com)
>
> Kevin Cunningham
> SMS
Kevin,
I bought my microscope from ebay a few weeks ago. I've never owned one or
hardly ever used one before. I'm very pleased with it; it is ideal for
botany, with magnification ranging from x24 to x400. It is a Prior with 3
object lenses and 2 eyepiece lenses. At the very bottom of each eyepiece is
what looks like a lens with a ring holding it in place. The ring has two
grooves diametrically opposite. That ring is virtually at the bottom of the
eyepiece. The eyepieces are about 2cms in diameter. Help would be very much
appreciated, let me know what additional information you require.

Regards, Peter

From:	Kevin Cunningham
Subject:	Re: Calibration
Date:	Wed, 29 Dec 2004 00:26:28 GMT

"Peter Bovey" wrote in message
news:m%dAd.55595$DF3.38684@fe3.news.blueyonder.co.uk...
>
>
>>
>> "Peter Bovey" wrote in message
>> news:qw_zd.7858$Ar5.6741@text.news.blueyonder.co.uk...
>>> Is it possible to buy a scale to put on the slide in order to measure
>>> the image? My eyepieces don't look as if they will support a reticle. I
>>> suppose the problem with putting a scale on the slide might be that at
>>> high magnification the scale and the object won't be in focus at the
>>> same time. Can any of you offer any advice on this matter? I'm wanting
>>> to identify mosses and it appears that I need to be able to measure the
>>> cells.
>
> "Kevin Cunningham" wrote in message
> news:NF3Ad.5138$qf5.2344@newsread3.news.atl.earthlink.net...
>>> Peter
>> Peter, Actually you can put reticule into any eyepiece I've ever seen.
>> While your idea is good, using a ruling on the slide, you would have
>> problems with expense and dept of field.
>>
>> The reticle can go on the inside of the eypiece or be held in place by a
>> very cheap jump ring. Let us know what kind of eyepiece you have and I
>> can let you know what to do. Oh, here's Klarmann Rulings, they make just
>> about all of the reticles (www.reticles.com)
>>
>> Kevin Cunningham
>> SMS
> Kevin,
> I bought my microscope from ebay a few weeks ago. I've never owned one or
> hardly ever used one before. I'm very pleased with it; it is ideal for
> botany, with magnification ranging from x24 to x400. It is a Prior with 3
> object lenses and 2 eyepiece lenses. At the very bottom of each eyepiece
> is what looks like a lens with a ring holding it in place. The ring has
> two grooves diametrically opposite. That ring is virtually at the bottom
> of the eyepiece. The eyepieces are about 2cms in diameter. Help would be
> very much appreciated, let me know what additional information you
> require.
>
> Regards, Peter
>
Peter, First contact Prior as Andy suggested. I'll bet that if you take the
eyepiece in both hands, one hand on the top plastic part and your other hand
on the metal part and gently twist (gently mean gentle twisting) it will
come apart safely. There will be a place to insert a reticle either on the
eyepiece diaphragm or above it. There maybe a screw off ring to hold it in
place. Please ask Prior what size the reticle should be before you order.

Be carefull but have fun!

Kevin Cunningham
SMS

From:	Peter Bovey
Subject:	Re: Calibration
Date:	Wed, 29 Dec 2004 14:11:00 GMT

"Kevin Cunningham" wrote in message
news:UQmAd.5956$qf5.555@newsread3.news.atl.earthlink.net...
>
> "Peter Bovey" wrote in message
> news:m%dAd.55595$DF3.38684@fe3.news.blueyonder.co.uk...
>>
>>
>>>
>>> "Peter Bovey" wrote in message
>>> news:qw_zd.7858$Ar5.6741@text.news.blueyonder.co.uk...
>>>> Is it possible to buy a scale to put on the slide in order to measure
>>>> the image? My eyepieces don't look as if they will support a reticle. I
>>>> suppose the problem with putting a scale on the slide might be that at
>>>> high magnification the scale and the object won't be in focus at the
>>>> same time. Can any of you offer any advice on this matter? I'm wanting
>>>> to identify mosses and it appears that I need to be able to measure the
>>>> cells.
>>
>> "Kevin Cunningham" wrote in message
>> news:NF3Ad.5138$qf5.2344@newsread3.news.atl.earthlink.net...
>>>> Peter
>>> Peter, Actually you can put reticule into any eyepiece I've ever seen.
>>> While your idea is good, using a ruling on the slide, you would have
>>> problems with expense and dept of field.
>>>
>>> The reticle can go on the inside of the eypiece or be held in place by a
>>> very cheap jump ring. Let us know what kind of eyepiece you have and I
>>> can let you know what to do. Oh, here's Klarmann Rulings, they make
>>> just about all of the reticles (www.reticles.com)
>>>
>>> Kevin Cunningham
>>> SMS
>> Kevin,
>> I bought my microscope from ebay a few weeks ago. I've never owned one or
>> hardly ever used one before. I'm very pleased with it; it is ideal for
>> botany, with magnification ranging from x24 to x400. It is a Prior with
>> 3 object lenses and 2 eyepiece lenses. At the very bottom of each
>> eyepiece is what looks like a lens with a ring holding it in place. The
>> ring has two grooves diametrically opposite. That ring is virtually at
>> the bottom of the eyepiece. The eyepieces are about 2cms in diameter.
>> Help would be very much appreciated, let me know what additional
>> information you require.
>>
>> Regards, Peter
>>
> Peter, First contact Prior as Andy suggested. I'll bet that if you take
> the eyepiece in both hands, one hand on the top plastic part and your
> other hand on the metal part and gently twist (gently mean gentle
> twisting) it will come apart safely. There will be a place to insert a
> reticle either on the eyepiece diaphragm or above it. There maybe a screw
> off ring to hold it in place. Please ask Prior what size the reticle
> should be before you order.
>
> Be carefull but have fun!
>
> Kevin Cunningham
> SMS
Kevin,
Yes you are right, the eyepiece does come apart. There is plenty of room
inside although no obvious fastenings. I will email Prior, although I did
that once before and never got a reply. I suspect that they are more
interested in selling their new electronic gear than helping me with my old
manual instrument. It doesn't appear to have a model number so I'm going
to have to describe it. I've no idea how old it is, but it's in good
condition.

Thanks a lot,
Peter

From:	Repeating Rifle
Subject:	Re: Calibration
Date:	Tue, 28 Dec 2004 05:17:09 GMT

in article NF3Ad.5138$qf5.2344@newsread3.news.atl.earthlink.net, Kevin
Cunningham at smskjd@mindspring.com wrote on 12/27/04 6:37 PM:

>
> "Peter Bovey" wrote in message
> news:qw_zd.7858$Ar5.6741@text.news.blueyonder.co.uk...
>> Is it possible to buy a scale to put on the slide in order to measure the
>> image? My eyepieces don't look as if they will support a reticle. I
>> suppose the problem with putting a scale on the slide might be that at
>> high magnification the scale and the object won't be in focus at the same
>> time. Can any of you offer any advice on this matter? I'm wanting to
>> identify mosses and it appears that I need to be able to measure the
>> cells.
>>
>> Peter
> Peter, Actually you can put reticule into any eyepiece I've ever seen.
> While your idea is good, using a ruling on the slide, you would have
> problems with expense and dept of field.
>
> The reticle can go on the inside of the eypiece or be held in place by a
> very cheap jump ring. Let us know what kind of eyepiece you have and I can
> let you know what to do. Oh, here's Klarmann Rulings, they make just about
> all of the reticles (www.reticles.com)
>
> Kevin Cunningham
> SMS
>
>
Another way, if you are willing to use photography, is to use certain
diatoms as scales. I have a slide with about six or seven species with well
known grating pitch. I just do not know how readily available they are.

Bill

From:	Peter Bovey
Subject:	Re: Calibration
Date:	Wed, 29 Dec 2004 13:55:43 GMT

"Repeating Rifle" wrote in message
news:BDF62C6E.2E0F5%salmonegg@sbcglobal.net...
> in article NF3Ad.5138$qf5.2344@newsread3.news.atl.earthlink.net, Kevin
> Cunningham at smskjd@mindspring.com wrote on 12/27/04 6:37 PM:
>
>>
>> "Peter Bovey" wrote in message
>> news:qw_zd.7858$Ar5.6741@text.news.blueyonder.co.uk...
>>> Is it possible to buy a scale to put on the slide in order to measure
>>> the
>>> image? My eyepieces don't look as if they will support a reticle. I
>>> suppose the problem with putting a scale on the slide might be that at
>>> high magnification the scale and the object won't be in focus at the
>>> same
>>> time. Can any of you offer any advice on this matter? I'm wanting to
>>> identify mosses and it appears that I need to be able to measure the
>>> cells.
>>>
>>> Peter
>> Peter, Actually you can put reticule into any eyepiece I've ever seen.
>> While your idea is good, using a ruling on the slide, you would have
>> problems with expense and dept of field.
>>
>> The reticle can go on the inside of the eypiece or be held in place by a
>> very cheap jump ring. Let us know what kind of eyepiece you have and I
>> can
>> let you know what to do. Oh, here's Klarmann Rulings, they make just
>> about
>> all of the reticles (www.reticles.com)
>>
>> Kevin Cunningham
>> SMS
>>
>>
> Another way, if you are willing to use photography, is to use certain
> diatoms as scales. I have a slide with about six or seven species with
> well
> known grating pitch. I just do not know how readily available they are.
>
> Bill
>
No, I can't use photography yet, thanks anyway.
Peter

From:	GTO
Subject:	Re: Calibration
Date:	Wed, 29 Dec 2004 05:42:44 GMT

Depending on your scope, you might just buy an ocular with the appropriate
eyepiece from Edmund Optics [1]. If your scope uses DIN and you are using
Achromats, a decent third-party ocular with a reticle should suffice. A
scale in the object plane is not recommended for this application.

Gregor

[1]
http://www.edmundoptics.com/onlinecatalog/browse.cfm?categoryid=206&level=2

"Peter Bovey" wrote in message
news:qw_zd.7858$Ar5.6741@text.news.blueyonder.co.uk...
> Is it possible to buy a scale to put on the slide in order to measure the
> image? My eyepieces don't look as if they will support a reticle. I
> suppose the problem with putting a scale on the slide might be that at
> high magnification the scale and the object won't be in focus at the same
> time. Can any of you offer any advice on this matter? I'm wanting to
> identify mosses and it appears that I need to be able to measure the
> cells.
>
> Peter
>