----- Forwarded message from morphmet_modera...@morphometrics.org -----
Date: Mon, 29 Oct 2012 22:22:13 -0700
From: morphmet_modera...@morphometrics.org
Reply-To: morphmet_modera...@morphometrics.org
Subject: Re: choosing a digital camera for collecting landmark data
To: morphmet@morphometrics.org
----- Forwarded message from al cardini -----
Date: Mon, 29 Oct 2012 05:05:37 -0400
From: al cardini
Reply-To: al cardini
Subject: Re: choosing a digital camera for collecting landmark data
To: morphmet@morphometrics.org
On the same line of thought, if one has a mm paper frame around the
object being photographed, one gets both clues on possible distortions
(often stronger near the edges) and the scale factor.
That's more or less what we did in Cardini & Tongiorgi, 2003.
Years later, I tested the accuracy of those 2D images compared to 3D
landmarks. That's unpublished but considering the flattening of the
third dimension and the interspecific level of the study, I'd say it
was pretty good on marmot hemimandibles (which are relatively flat).
If there's a chance to do a similar test on a subsample and possibly
compare different setups and cameras, it could be worth the effort.
Cheers
Andrea
On 29 October 2012 08:54, <morphmet_modera...@morphometrics.org> wrote:
>
> ----- Forwarded message from Rich Strauss -----
>
> Date: Fri, 26 Oct 2012 15:45:30 -0400
> From: Rich Strauss
> Reply-To: Rich Strauss
> Subject: Re: choosing a digital camera for collecting landmark data
> To: morphmet@morphometrics.org
>
> In addition to the desirable camera characters listed by others, I think
> that it's important always to check carefully for lens distortion by taking
> a photo of high-quality graph paper and checking for straight lines
> (numerically by digitizing grid points). I've used several different kinds
> of cameras and lenses, and have found that distortion near the edges of the
> field can be quite significant. I also found an Olympus macro lens to have
> unacceptable distortion in one small area just to the left of the center of
> the field.
>
> Rich Strauss
>
> At 02:57 PM 10/25/2012, you wrote:
>
>
> ----- Forwarded message from Alexandre Silva de Paula -----
>
> Date: Wed, 24 Oct 2012 18:29:01 -0400
> From: Alexandre Silva de Paula
> Reply-To: Alexandre Silva de Paula
> Subject: Re: [Spam] Re: choosing a digital camera for collecting landmark
> data
> To: morphmet@morphometrics.org
>
> Dear Sive,
>
> I think you will find one appropriate microscope on page
> http://www.dinolite.com/ I have one AM4013ZT4 Dino-Lite Pro with one Suporte
> DinoLite MS-35B Stand Rack. They work fine. You will find an appropriate
> microscope.
>
> Best wishes,
>
> Alexandre.
>
> On Oct 24, 2012, at 6:57 PM, morphmet_modera...@morphometrics.org wrote:
>
>
> ----- Forwarded message from "Novack-Gottshall, Philip M." -----
>
> Date: Tue, 23 Oct 2012 12:24:15 -0400
> From: "Novack-Gottshall, Philip M."
> Reply-To: "Novack-Gottshall, Philip M."
> Subject: Re: choosing a digital camera for collecting landmark data
> To: "sfin...@tcd.ie"
>
> Dear Sive,
>
> I work with fossil invertebrates, which tend to be a bit easier to
> photograph and digitize because they're typically somewhat flattened and
> two-dimensional. But hopefully this will be useful for your specimens.
>
> In my experience, any decent camera does fine. I've listed the various
> equipment I've used on my website:
> http://www1.ben.edu/faculty/pnovack-gottshall/PaleoDIMPL.html
>
> Overall, the most important factors are to (1) use a scale bar, (2)
> understand your camera settings (especially the aperture-priority setting),
> and (3) use a camera/copy stand to keep your camera steady.
>
> Use of a scale bar is always critical; without it, you're very limited in
> the kinds of analyses you can do (although some shape-based morphometrics
> are OK). But given it is so easy to include one in every photograph, there's
> no reason not to. Just make sure that the scale bar is positioned close to
> you specimen (i.e., not along the border of your field of view, where you
> can get aberations) and in the same vertical plane as your specimen (to
> prevent parallax-focus issues). You also want to make sure the scale bar is
> in focus.
>
> I often use a macro lens to get get large images of small specimens. In
> these lenses, the focal depth is dramatically reduced. (This is true for
> regular lenses, too.) The key in both is to use the aperture-priority
> setting (sometimes with different names in different camera models.) The
> aperture setting (sometimes called an f-stop of f-number) allows you to
> change the focal depth of your images. (Large f-numbers, such as f/16 use a
> very small aperture but allow a "deep" field of view; small f-numbers, such
> as f/2 have larger apertures and shallow fields of view.) This is important
> so that parts of your specimen close to you are as much in focus as parts
> away from you. The downside of a large f-number is that it takes more time
> for your camera to compensate for the reduced light passing through the
> aperture, which means the shot takes longer. If you are holding the camera
> by hand, it's essentially impossible to get a well focused image because of
> the camera shake. So a camera/photo stand is critical. (Another downside is
> that some lenses produce less focused images at extreme f-numbers, so you'll
> need to play with your camera and set-up to find the optimal settings to get
> sharp images with "deep" fields of view.)
>
> Finally, although a photostand is large and cumbersome (and not something
> you'd expect to travel with), it is very helpful for trying different
> settings, playing with different lighting scenarios (another important
> factor that can be critical in making a "flat" image of a non-flat specimen
> look non-flat), and especially for getting sharp focus (whether using large
> f-numbers of not.) (Lighting is also important when playing with f-numbers
> because a brightly lit specimen can be blanched by too-much lighting, even
> if relatively dim, if the aperture is open for a few seconds.) Most museums
> have photostands available if you ask. They're a critical tool if you are
> serious about photographing specimens.
>
> (As an aside, most copystands use incandescent lighting, which can get
> incredibly hot when turned on for a batch of specimens! The only copystand
> I've seen that uses non-incandescents is a rather pricey model by Bencher
> that uses flourescent, but is well worth the price, in my opinion. Although
> it's not a traveling model by any stretch.)
>
> Finally, depending on the f-numbers you use, you might consider using a
> remote switch (or a computer program that speaks to the camera), which can
> allow you to "click" the camera to take the picture from a distance, further
> reducing the camera shake on the camera which is the enemy of a sharp focus.
>
> Best wishes,
> Phil
>
> On 10/23/2012 12:27 AM, morphmet_modera...@morphometrics.org wrote:
>
>
> ----- Forwarded message from Sive Finlay -----
>
> Date: Sun, 21 Oct 2012 10:17:26 -0400
> From: Sive Finlay
> Reply-To: Sive Finlay
> Subject: choosing a digital camera for collecting landmark data
> To: morphmet@morphometrics.org
>
> Dear all,
>
> I'm starting a new PhD project studying convergent evolution in Malagasy
> tenrecs (Tenrecidae). I want to compare morphological similarities among the
> skulls and limbs of tenrecs and convergent species (moles, shrews, hedgehogs
> etc.)
> I'd be very grateful for advice on which cameras and/or lighting set up
> would be suitable for photographing museum specimens for later analysis
> using landmark data.
> I'll be travelling to different museums so ideally I would like equipment
> which is easily portable and can be re-assembled to create consistent
> photographing conditions.
>
> Any tips or advice on which equipment might be suitable would be much
> appreciated.
>
> Thanks
>
> Sive Finlay
> sfin...@tcd.ie
>
> --
> Sive Finlay
> IRC EMBARK Initiative Postgraduate Scholar
>
> Macroecology and Macroevolution Research Group
> Zoology building
> School of Natural Sciences
> Trinity College Dublin
>
> sfin...@tcd.ie
> http://www.tcd.ie/Zoology/research/ncooper/people.php
>
>
>
> ----- End forwarded message -----
>
>
>
>
> --
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> Phil Novack-Gottshall
> Assistant Professor
> Department of Biological Sciences
> Benedictine University
> 5700 College Road
> Lisle, IL 60532
>
>
> pnovack-gottsh...@ben.edu
> Phone: 630-829-6514
> Fax: 630-829-6547
> Office: 332 Birck Hall
> Lab: 107 Birck Hall
>
> http://www1.ben.edu/faculty/pnovack-gottshall
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
>
>
>
> ----- End forwarded message -----
>
>
>
>
>
>
> ----- End forwarded message -----
>
>
> =============================================================
> Dr. Richard E. Strauss (806) 742-2719 (voice)
> Professor, Biological Sciences (806) 742-2963 (fax)
> Texas Tech University rich.stra...@ttu.edu
> Lubbock, TX 79409-3131
> < http://www.faculty.biol.ttu.edu/Strauss/Strauss.html>
> =============================================================
>
>
>
> ----- End forwarded message -----
>
>
>
--
NO DOCX, XLSX AND PPTX, PLEASE!!!
COAUTHORS AND CONTRIBUTORS, PLEASE, FOR SHARING FILES, CONVERT THEM IN
DOC, XLS (UNLESS LONGER THAN 256 COLUMNS) AND PPT
Dr. Andrea Cardini
Researcher in Animal Biology
Dipartimento di Scienze Chimiche e Geologiche, Università di Modena e
Reggio Emilia, l.go S. Eufemia 19, 41121 Modena, Italy
Honorary Fellow
Functional Morphology and Evolution Unit, Hull York Medical School
University of Hull, Cottingham Road, Hull, HU6 7RX, UK
University of York, Heslington, York YO10 5DD, UK
Adjunct Associate Professor
Centre for Forensic Science , The University of Western Australia
35 Stirling Highway, Crawley WA 6009, Australia
E-mail address: alcard...@gmail.com, andrea.card...@unimore.it,
andrea.card...@hyms.ac.uk, andrea.card...@uwa.edu.au
Webpage: http://sites.google.com/site/hymsfme/drandreacardini
Datasets:
http://ads.ahds.ac.uk/catalogue/archive/cerco_lt_2007/overview.cfm#metadata
Editorial board for:
Zoomorphology:
http://www.springer.com/life+sciences/animal+sciences/journal/435
Journal of Zoological Systematics and Evolutionary Research:
http://www.wiley.com/bw/journal.asp?ref=0947-5745&site=1
Hystrix, the Italian Journal of Mammalogy:
http://www.italian-journal-of-mammalogy.it/
----- End forwarded message -----
----- End forwarded message -----
