Yesterday, after a rather excruciatingly long flight, I arrived in Armidale. I’m spending two weeks here with the FEAR Lab, doing some modelling work. I’ll obviously report on that, but for now I just want to dump a bunch of photos on you.


This is a shot from my stopover in Sydney, where I went through immigration and – surprise! had to stand in line again for customs. Well, quarantine….. which makes a lot of sense, seeing how Australia has a flora and fauna totally separated from much of the rest of the world. Therefore, they do a quick check of what people and luggage they want to check in detail at the customs check, and that caused a line to form. This little incident made being on a totally different continent quite real for me.

Oh, and as you can see, all of Sydney easily fits under an A-380 wing ;)


Unsurprisingly, a totally different fauna also means totally different birds. So far, I’ve only seen one species of bird that I’ve seen before outside zoos – unsurprisingly the European starling. Other than that Armidale is full of Australian magpies (Cracticus tibicen), above on the antenna of my hotel, who make their ubiquitous presence very well heard all over town. Being used to corvids making “koww” of “cawh” sounds, it is weird to hear a bird that looks just like one imitating a flute, from which they got their German name of Flötenvogel (flute bird).


I also saw several kookaburras, Dacelo novaeguineae. This one flew in and sat on the playground equipment in a park while I stood a few meters away.


A red wattlebird (Anthochaera carunculata) – I heard a lot of them, and saw several.

and lots more – for two hours of walking around town(!) I photographed a surprisingly large number of taxa.

Posted in Aves, Maniraptora, Theropoda | 2 Comments

Theropod Thursday 53: Snow White

Last Monday, work took me to the Weltvogelpark Walsrode (wikipedia). It is really weird that I haven’t been there before, and I was determined to make the most of this visit, despite a so-so weather forecast. The Weltvogelpark is a huge one, the largest bird park in the world both in number of species and land area (claims wikipedia), and it has only birds (no, not even guinea pigs somewhere), as opposed to many other bird parks. You’ll get Theropod Thursday-ed to death here with photos I took there, but today I want to focus on a handful of birds I saw that that have one thing in common: they are white.

Let me warm you up with a bird that is mostly white – in the photo below I managed to “hide” the dark head in an underexposed background ;)

Madagascar sacred ibis

This is Threskiornis bernieri, the Madagascar or Malagasy sacred ibis. Looks a bit ruffled, which is not surprising. Monday was a stormy and rainy day, with some hail thrown in for fun, too. The next bird doesn’t look ruffled, and doesn’t have any non-white feathers.


Can you guess the species? Or at least the genus?

OK, more info may help you……


recognize it now? It good old Corvus corone, the Carrion crow! An albino one, to by sure, as the red eyes show. Real albinism, a total lack of the pigment melanin, is much rarer than just a reduced amount of melanin, a condition called leucism. Leucistic animals (including humans) typically have enough pigment in the iris to make it not totally translucent, and so we do not see the blood vessel rich retina.


Yep, an albino! And if this bird doesn’t deserve the name Snow White, maybe this one does:




As you can see, this peacock (Pavo cristatus, I guess from the head shape and the other animals running free in Walsrode) is leucistic, but not an albino. The eyes are black.

So that’s two really rare things here: an albino crow and a leucistic peacock – in one place. But Walsrode has much more to offer than just freaks (as I threatened above). Today, I’ll wrap up the post on white birds with one that is completely white except for its beak and the tips of a handful of feathers: the coscoroba swan (Coscoroba coscoroba). Walsrode has a pair, and while one of the was sitting on the nest, the other was quite a show-off. Clearly, the intent was to keep us sufficiently impressed so that we would stay away from the nest. The coscoroba isn’t the biggest of swans, but its ego is certainly not too small.








Posted in Aves, Dinopics, Dinosauria, Theropoda, Weltvogelpark Walsrode, Zoos | 1 Comment

Theropod Thursday 52: pulling a leg! Erhm….rather: pulling a tail!


Hungry I am. An aardwolf (Proteles cristata), too. A hungry aardwolf. Yep, that’s it. A hungry aardwolf. Now get me my food. Now!

This is the elusive critter that David Hone, my esteemed colleague with plenty of zoo experience, and I totally missed seeing during our legendary winter visit. Legendary for me, as it made me aware of how much cooler a zoo the Tierpark is than I was previously taking note of. Dave kept repeating “I’ve never seen this animal before!” The aardwolf was the one animal that we really wanted to see but didn’t. And on my many other visits to the Tierpark – I place I practically live at during summer weekends – the aardwolf stayed elusive. I did see it, but generally just as a furry blur popping out of one hole in the ground and into another one.

So imagine my delight when the Tierpark, under the new director Dr. Knieriem, started announcing the feeding times of some of the animals, and included not only the echidna but also the aardwolf on this list! Obviously, I dragged my children there at the appointed time, 2:15 p.m. And lo and behold, the elusive aardwolf put in an appearance! He came out of his hiding place when fodder was presented and greedily gobbled it up.



But, waitamoment!” you say. “What’s this to do with Theropod Thursday?

Well, here goes:


A hooded crow (Corvus cornix) is paying a visit. And not a polite one, as we will quickly see.

Aardwolves feed mostly on termites, so the Tierpark feeds them a pretty yucky looking protein-rich slurry. And believe me, crows love anything protein-rich. And crows being crovids, some of the most inventive birds, they come up with ways to make you, me, and aardwolves involuntarily share that yummy protein cocktail.




and pull!

Hm, ain’t nothing happening. Well, let’s do this again.



Now, corvids have a pathological obsession with tail pulling. They just can’t help themselves! See here. If it’s got a tail, that tail’s gotta be pulled!

Still no effect? Here we go again!




Oh wow, finally there’s a reaction!



and so, finally, the poor crow that risked life and wing got the deserved go at the trough!

To be honest, I don’t believe the aardwolf minded the tail pulling very much. He simply had had his fill, and thus would have wandered off anyways.
To end this on a more theropodish than mammalian way, here’s a Hooded crow proudly strutting around.


Posted in Aves, Dinosauria, Mammal pic, Mammalia, Maniraptora, Theropoda, Zoos | 1 Comment

Photogrammetry tutorial 9: Quick and dirty!

Over the course of previous tutorials and in my paper with Oliver Wings I’ve given quite a bit of advice on how to photogrammetrize objects properly. Today, I’ll address the other end of the spectrum: how to approach photogrammetry unprepared and without proper equipment. Oliver and I mentioned a minimum kit in our paper, but what if you’re really stuck with just a digital camera? What can you do with everyday materials to improve your results, and how do you approach the entire thing?

First of all, you really need to know how to handle your camera. If you have a tripod and control over the lighting, it is easy to take in-focus and well-lit images. But if the light is low, comes from one direction, and you must hand-hold your camera, then it becomes important that you know with which lens at what zoom setting you can reliably take good photographs with what ISO settings. There’s one thing that will help you a lot that usually I’d strongly recommend against: use flash! Yes, you read that right: it is better to use a flash, even your camera’s internal flash, than take blurry photos. (If your camera doesn’t have an internal flash, then it is a top notch DSLR and I can’t believe you don’t have a whole shitload of equipment with you). There’s an important thing to do when you use your internal flash, but I’ll save that for later when I talk about the process of photographing a specimen.

One thing to remember is that your zoom lenses will allow shorter exposure times / lower ISO / smaller apertures if you use them at a low extension length. So do consider stepping closer to the specimen rather than zooming in. As long as you do not go into the ultra-wide angles or use a fisheye, your models should turn out just fine. And if your modelling software happens to be Agisoft Photoscan Pro, you can even use a fisheye lens, as the program has a feature that allows dealing with fisheye distortion.

Another issue with q&d photogrammetry is usually the inability to use a turntable or optimize the background. Normally, you’ll want to use a background that doesn’t offer any features for the software to detect. However, given the lower quality of images you are wont to achieve, using a feature-rich background can actually be a boon! Normally, you’ll always want to aim for one-chunk model creation, where you toss all images into one chunk, even if the specimen was moved versus the background in between. Instead, now try to use a highly structured background, such as a colour ad newspaper page! And once you’ve finished shooting the specimen from one side and move it by flipping it over, use a different feature-rich background! This way, the background can be included in model creation and thus help with alignment, but doesn’t cause images to align based on the background that were taken with different specimen positions.

Let me explain step by step:

  1. Put specimen on a double-wide newspaper page with colour adverts, or some other crazy stuff. Persian rug or whatever.
  2. Clean, as far as possible, the area around or use additional newspaper etc. to hide anything that would be in the picture.
  3. Shoot images from all around.
  4. Remove specimen and all stuff you used to cover the table.
  5. Place different newspaper – maybe even something totally different like a tablecloth.
  6. Return specimen in different position (flipped over).
  7. Shoot images from all around.

Now, you can use multi-chunk alignment with points-based chunk alignment, as nothing but the specimen is there to make the chunks match each other. Granted, it may not work, but you can always resort to manually placed markers.

OK, now is the time to say that bit about using the internal flash. Obviously, in an ideal world, you have brought a ring light (usually LED) or ring flash, but let’s assume that you haven’t. If you point your camera at the specimen you’ll usually hold it upside up, so that the flash is above the lens. And in normal conditions, whether outside or indoors, the majority of the light will come form above. This means that you naturally get a darker, less-lit underside of the specimen, and that you add to this effect by having the flash light slightly from above, too. So, fix this: flip your camera upside-down! It sounds stupid, and it can be cumbersome, but having the flash under the lens gives you an extra 10% or so of surface you capture well-lit, right where it matters: on the outward edge of the specimen, where you want to find many good points to match one chunk to another.

What else? For one thing, do try out unusual camera programmes! Many DSRLs and even cheap point&shooters offer HDR modes. These modes take several images at different ISOs (usually) or exposures (better but rarer), and combine them into one image that is more evenly lit than any normal photo. As this post direly needs a photo now, here’s one – a HDR mode photo I took with my Canon EOS 650D of the AMNH’s Tyrannosaurus mount.

AMNH T. rex

AMNH T. rex

Oh well, it’s a cool mount, so two photographs instead of one ;) Notice how there are no black shadows and no white-outs? That’s the power of automated HDR. Sadly, the 650D does this via ISO variation, and that includes high ISO values, leading to a lot of noise in the image. But still: these images align and produce dense point clouds much better in Photoscan than normal, hand-held ones would. So, no tripod? Try the HDR mode! If you run Magic Lantern on your camera, you can do better, varying the exposure, not the ISO, too.

Anything else? Consider making a makeshift turntable from a sandbox or so for small specimens, or just using a smooth board on a smooth table. Use white pieces of paper or white shirts to reflect light onto specimens. And so on – happy digitizing! :)


Posted in AMNH, Digitizing, Dinopics, Dinosauria, How to, photogrammetry, Theropoda, Tyrannosauridae, Tyrannosaurus | 5 Comments

Photogrammetry tutorial 8: scaling “with hindsight”

Recently, I mentioned in passing that I took some photographs of specimens at the AMNH in New York so that I could better scale models I had calculated from photographs taken during my previous visit. Here’s how that worked out, with a step-by-step explanation.

Here’s one of the models again, as calculated before, without a proper large scale bar.


If your name is Jaime H., click for a larger version ;)

This is a model of the Khaan mckennai holotype IGM 100/1127. It has only some 17.5 million polygons. Still, a nice model! Obviously, given the advances in the photogrammetry software that happened since I previously calculated the models, I could simply have re-run them from scratch, just with the new images added. In fact, I am doing that also, to compare the results. But with a calculation time of 183 hours for the alignment and 75 hours for dense point cloud generation – and that is for ONE of the models – it is a major task. If I can avoid it, that’s an option nice to have. I just recalculated on of my models, and that has 279 million points in the dense point cloud. So, “only” 17.5 million here, but a model that I certainly do not wish to re-calculate, as it is good enough for the vast majority of purposes.

So, how to proceed?
First of all, I created a new chunk in the project file, and added my new photographs with the big scale bars into it. I ran alignment, obviously at ‘High’ accuracy. Then, I added markers on my scale bars in the photographs:


Obviously, the surroundings have changed. And if you look closely you will note that the specimen itself has changed a bit, due to further preparation work. However, the by far largest part of the area photographed has stayed the same. Therefore, it is now possible to align the two chunks to each other via points. And then I merged the chunks, which retained the already-calculated model.


This is the chunk with the old photos, showing the alignment. And here’s the two chunks aligned and merged:


Note that I set the alignment photos to “inactive” so that they are shown in a different colour.

Now, I just updated the merged chunks using two scale bars created from the four markers – and done!

OK, that’s it! And now, to tease certain colleague a bit more, another view of the model. This time without colour, so that the high quality is more apparent:






Posted in AMNH, Digitizing, Dinopics, Dinosaur models, Dinosauria, Khaan, Maniraptora, Oviraptorosauridae, photogrammetry, Theropoda | 7 Comments

Attempts at macro photography of minerals

Software for photogrammetric 3D reconstructions pretty much doesn’t care what scale the photographs are that you feed it. As long as there are pixels and EXIF data, all is fine. Without EXIF it requires a bit of fiddling; see for example the wonderful Paluxy river trackway 3D model in this paper. Wish I’d done it! I had played with the idea, but Peter Falkingham was so much more obviously the guy to do it… well, anyways. Software doesn’t care about scale, so you can feed in satellite images or macro images – it will calculate ahead. I did some macro photogrammetry before (here and here), but in both cases I loaned the macro lens only for that specific purpose. However, I wanted to play around with the lens a bit for straightforward macro photography, too. Now, I finally got around to that.


Markasite FeS2 and Lostlabelit (maybe Cerussite PbCO3 ?
I’m too lazy busy to check right now)

The lens in question is one of the coolest toys in this field you can imagine: a Canon MP-E 65 mm! What’s so cool about it is that, although it seems, from its name, to be  regular 65mm macro lens, it is in fact a 5:1 lens! Yes, you read that right: 5x magnification! You can go all the way from 1:1 to 5:1! Most macro lenses go from 0.5:1 to 2:1 or so.


Vanadinite Pb5(VO4)3Cl

The huge magnification does have its drawbacks, though. For one thing, the lens does not have autofocus. When you see it in action, it becomes immediately clear, why an autofocus would not really be a good idea. The dinky 65 mm’s 98 mm total length turn into a whopping 300 or so mm (I didn’t measure) – this lens is longer when used at 5x magnification than many a good tele! And focusing via the focus ring and changing magnification is the same thing – therefore, I tend to set magnification first, then move the whole camera or the subject until it is in focus.


Anapaite Ca2Fe2+(PO4)2·4H2O


Bornite tarnish Cu5FeS4


Calcite CaCO3

Overall, this lens quite clearly is not for the noobs and lazy out there! I count among the former, but I did have a lot of fun with it. It makes many of my at first glance boring minerals and crystals look really impressive, and the effort is tolerable. And it is surprisingly cheap (well, kinda) at currently slightly over 1000 €! As a colleague wrote on Facebook, he gets better results photographing microfossils with this lens than with the Senckenberg’s dedicated equipment that costs 40x as much.

Posted in macro, photography | Leave a comment

Absurd Addendum to Gut Check

Yesterday, I posted some pictures that I took with a fisheye lens. As mentioned, one has to be hellishly careful not to get into the picture by accident. Well, I mentioned lying down on the floor…….



Note the camera under Diplodocus‘ belly.

Also, I took an unintended selfie. My tripod head allows tilting the camera down to 90°, and up to 45°. If I want to tilt it any further, I need to reverse it: take it off, loosen the screw that fixes the holder plate to the camera, turn the plate around 180°, then fasten the screw again and set the camera back onto the tripod. I did this without turning the camera off, and because it was in liveview mode, where you can release the shutter by touching the liveview screen, and because I happened to brush against the screen when I set the camera back into the bracket….. well, the camera was, due to the rotation, pointing in the exact opposite direction of “upward at Giraffatitan;)


There you go, critical looking palaeontologist with Elaphrosaurus. Needs a shave ;)

Posted in FUN!!!, photography | 2 Comments