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Using shadows to date photographs (part 2)


In commenting on my first post about using shadows to date photographs Michael Smith asked a number of questions about the process. This post is a response to those questions (the questions are marked in italics below.)

When discussing our dating experiments at the University of New England and Regional Archives, I should first point out that I have the services of a most talented volunteer with a background in both history and information technology. This gentleman is Mr Michael Reed who is refining his expertise in the technique based on the book:

“Forensic Genealogy” by C Fitzpatrick ISBN: 9780976716006   (This book contains the CD to generate the math.)

Booloominbah and Nurse on Penny Farthing A1473 Booloominbah and Nurse on Penny Farthing

This is a sample image that we are going to work on.  The clothing and equipment gives us an approximate date range and then we have the exact location of the site. The question here revolves about whether we have enough information to judge the length of our shadows.


(1) Did you already know the date of the photos you tested?  i.e. Did you test first on known dates to see how accurate the calculations are?
We had an estimated date range based in information gained from details of the award of the Victoria Cross to Jackson and his service records. This placed us to within 18 months of the event. We then looked for shadow and applied the algorithm that produced a table of possible dates.  Then we were able to seek newspaper confirmation of the event.

(2) How many dates does the algorithm spit out? (I’m sure it varies but ball park)
The algorithm is basically a reverse sundial producing many dozens of possible dates over many years from the photo location and the length of shadow.

(3) Do you need to know where the photo was taken to get an accurate date.  We use a range of factors to identify dates in our photographic collection. This can be very time consuming and not always terribly accurate. And of course there are some where I suspect we will just never know.
The exact location of the photo is critical to the process. Without knowing your location on the planet, you cannot work out the location of the sun to get the date and time.

Finally, shall we see this written up in more detail in, say, a distinguished journal, at some stage?
I think that Michael Reed would be the potential author of any serious journal article generated out of this work. His understanding of the issue is complimented by his available time to experiment. I am just concentrating on just locating images that have both sun and location to give ourselves more practice at the technique.

Empire Day 1908 ALA22 Empire Day 1908

This is an example of a photo that would be more challenging to date using this technique although here the date is a given. This image ALA22 provides dating evidence in its titling. However, none of the buildings in this photo still exist. ALA22 does not have any real hint as to the location of north even though I know the city block where this was taken. I suspect that Michael would delve into the tree line in order to identify this. When using a sundial in reverse, you have to know exactly where it stands. I like this photo.

  • John Ruffels says:

    Hello William, Michael and Fiona,
    Kimberly O’Sullivan-Steward, Local Studies Archivist at Waverley Library forwarded this for my information.
    It was a revelation to learn known locations could afford set shadow lengths to produce a possible date-range for old photos.
    I am very interested in this subject, having provided some help to Peter Doyle of the Historic Houses Trust
    “City of Shadows ” books and exhibition. (Actually Police & Justice Museum).
    I have become interested in assembling a body of sympathetic fellow-enthusiasts to explore ways of identifying what one website describes as “Orphan Photographs”. Those vast collections of unidentified photos in archive collections and even antique store shoe-boxes.
    I was aware Nazi-hunters used characteristics of people’s ears as an identifier; and now we have shadow algorithms.I know there already books: but most are unsatisfactory.
    I am first anxious to find just how many natural “photo-sleuths ” there are out there.
    People who are very observant. And who can glean those all-important preliminary clues from which first steps in I.D.-ing a snapshot begin.
    For instance, how many people noticed in the above photo outside the pub, (the top photo) it is possible to see a clock face on the pub wall?
    I also have a question about the V.C Winner Recruiting Rally. Which soldier in the photo is Jackson V.C.?
    I have read his ADB entry and it says he lost “an arm” in France in June 1916! Not just a hand.
    It is of course, possible to narrow date ranges by observing fashions in dress, and possible seasons by the lack of foliage on visible vegetation.(See the creeper on the wall behind the cyclist nurse).
    Eventually, I would like to assemble a useful, comprehensive guide to ” snapsleuthing “.
    And I am sure there are a lot of people out there who can help me develop a methodology.
    JOHN RUFFELS ,Waverley, NSW.

    August 16, 2009 at 9:59 pm
  • Fiona Sullivan says:

    Hi John,
    Thanks for your comment. I agree “Snapsleuthing” can be a lot of fun! Unfortunately, it’s not something that we have a lot of time to do due to the size of our collection. However, since State Records has started publishing photo’s on flickr ( two users (beachcomberaustralia & lifeasadaddy) have been helping out by adding date and geographical information as well as exploring links with other photographic collections. The internet is opening up so many new opportunities for the use of collections. Paul Hagon from NLA used images of railways stations State Records had geo-tagged and uploaded onto flickr to create this now and then mash-up . In another aside I don’t know if you caught the earlier link from Bob Meade showing some first rate detective work on a civil war photograph I’ll leave my colleagues from the University of New England to weigh in on the W. Jackson question.

    August 18, 2009 at 9:41 am
  • Bob Meade says:

    I think that there is a very interesting discussion with practical example of using the Sun’s known azimuth and shadows to date, or rather put two photogrpahs in order of being taken at this blog post by Errol Morris:

    But beware, that blog post is number three in his series and the whole series demands plenty of time to digest.

    September 28, 2009 at 2:13 pm
  • Bob Meade says:

    Also, should anyone be interested, I will be giving a brief talk about “Snapsleuthing” or being a history detective through photographs at the Common Ground event at Sydney’s Powerhouse Museum this Saturday evening, 3rd October.

    See details here:

    “Snapsleuthing”. I love that word that I’ve just seen here. I’ll use it in my talk I think.

    Paul Hagon will also speak at the same event.

    September 28, 2009 at 2:18 pm
  • Anthea Brown says:


    Thanks for adding the link and your plug to the Common Ground event. I can see dating shadows and ‘snapsleuthing’ becoming a theme!

    September 28, 2009 at 3:20 pm
  • JOHN RUFFELS says:

    Hello Fiona, Bob and Anthea,

    I have been frantically engaged in other areas, so have only just got back to this site.

    My apologies for my seeming to ignore you all.

    I am particularly aggrieved at having missed the Common Ground talks at the Powerhouse last October.

    Thanks for the links, Bob, and Fiona, especially to the U.S. ones Bob. Much very interesting work done there.

    As you all suggest, there is a vast field involved in

    And yes, I hope, if nothing else, my coinage of
    “Snapsleuthing” catches on, then I will have made one contribution to an area I am only just realising the vastness thereof.

    And yes Fiona, the Internet is an ideal tool for opening this area up.

    But what a shame Archivists and Curators have too little time to allot to translating one-dimensional images into three dimensional stories – the Civil War photos and the Australian ones show its potential.

    Perhaps with Face Recognition technology and Google’s satellite images of buildings, the process might be simplified and made more economical.

    JOHN RUFFELS, Waverley.

    February 7, 2010 at 6:25 am
  • harry4history says:

    John Ruffels,
    For information on Jackson VC, contact Harry Willey, Scone

    September 24, 2010 at 4:43 pm
  • John Ruffels says:

    Extremely abject apologies Harry4history.
    For my rudeness in not acknowledging your useful contact tip.
    I’m horrendously occupied elsewhere just now, so I’ll pop back later and contact Harry Willey of Scone.

    April 3, 2011 at 7:17 pm
  • Harry Willey says:

    Contact requiredwith John Ruffels, ABD Website have just altered thier page on Jackson after I was eventually able to convince them of the mistakes they had made.
    My two years at UNE as a mature aged external student paid off.

    June 20, 2012 at 5:26 pm
  • John Ruffels says:

    Attention Harry Willey:Thank you very much for telling me the ADB entry for Jackson (V.C.) was incorrect. Congratulations on being accurate! Just goes to show how useful this whole exercise is. Not just for sleuthing clues in snaps, but also for questioning, when things don’t tally.(My usual apologies for tardiness.I am sorry).Yes your two years at UNE really did pay off.

    September 25, 2012 at 6:26 pm
  • harry Willey says:

    Thanks John. The AD of B have just corrected information they had on cameron, Donald (1877 – 1950. This did not take the time and effort in having the Jackson story corrected.

    October 24, 2012 at 2:21 pm