[Histonet] quick and dirty scale bar

[Marshall Terry Dr, Consultant Histopathologist]

This is a tad bizarre. I had this problem recently, spending hours
getting pictures just right for a junior's paper, then finding after
submission, that they wanted magnification (useless information) and
didn't want the helpful arrows which would point the uninitiated in the
right direction.
There was nothing for it but to start again.
Proper pathology journals gave up putting magnifications or scale bars
years ago (EM pictures excepted). 
It's just the  other non-pathology journals which want it, and it's
totally meaningless, empty information.

I suggest you bullshit. Take a few red cells, call them 6mu, and put on
a scale from that. Who's to know the difference?

Terry

-----Original Message-----
From: histonet-bounces <@t> lists.utsouthwestern.edu
[mailto:histonet-bounces <@t> lists.utsouthwestern.edu] On Behalf Of Philip
Oshel
Sent: 19 June 2007 14:02
To: Histonet <@t> Pathology.swmed.edu
Subject: Re: [Histonet] quick and dirty scale bar

Caroline,

No, you can't use the 40X scale bar, and yes, it's not that simple. 
Even if the image with the 40X scale bar were taken on the same
microscope with the same camera and the same settings, it wouldn't be in
an exact 1:4 relation with the 10X objective.
Further, you don't know what if any zoom your collaborator used. If the
image was taken with a standard digital camera (e.g., a Nikon
Coolpix) through an eyepiece adapter, there is often vignetting around
the edges. This prompts people to use the zoom function to eliminate
this. Which of course means the image isn't "10X".
Which it may not have been anyway, depending on the lens in the eyepiece
adapter.
The only way to get images with known scale bars is to take a micrograph
of a stage micrometer **without changing the camera**, especially the
zoom, for each objective used, *at the time the micrographs are taken*.
Otherwise it is nearly impossible to replicate the zoom used.
Calculations/measurements based on field of view aren't trustworthy for
the same reasons -- you don't know the true field of view.
If no zoom was used, then it may be possible to take a photo of a stage
micrometer with the same objective, etc., and be OK. But I wouldn't
trust it.

Given what you have, there are really only 2 courses: first, is there a
structure in the micrograph you have that has a well know  size? 
RBCs don't count, they change size by a micrometer or more depending on
how they're treated (and yes, still look like nice, biconcave discs). If
there is, you can calculate magnification and therefore a scale bar from
it.
But likely not. The other recourse is to have you collaborator take the
image again, and this time also take an image of a stage micrometer.
Anything else is just guessing.

Phil

>Hey Guys,
>
>I'm trying to finish up some figures for a paper.  One collaborator has

>given me 10X images that appear to have been taken from a standard 
>digital camera.  Can anyone suggest a quick and easy way to add a scale

>bar?  Unfortunately the journal requires it and I just don't have it.  
>I have a scale bar for a 40X picture from a different 
>microscope/experiment, any chance that I can use this?
>I'm guessing it is not as simple as my 40X scale bar being 1/4 of the 
>10X?
>
>Sorry, but I am clueless about this...  any suggestions would be
appreciated.
>
>Thanks,
>
>Caroline
>
>
>
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--
Philip Oshel
Microscopy Facility Supervisor
Biology Department
024C Brooks Hall
Central Michigan University
Mt. Pleasant, MI 48859

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