Home Made Photogrammetry Studio Setup

Home made light tent

Making your own light studio is a great way to improve the quality and consistency of lighting which goes a long way to improving the accuracy of photogrammetry. It doesn’t need to be expensive either. I was able to make mine for less than £30. You can pick up a cheap light tent kit from Amazon for less than £70 if you don’t want to make your own, but where’s the fun in that?

Here is a list of what you need ..

  • Cardboard box (get double-walled for extra strength)
  • Tape (masking tape for paper and something strong for box)
  • Tracing paper (roll or A3 pad)
  • 3 x desk lamps with daylight bulbs (I got these from Wilkos for £8 each)
  • Lazy Susan or other tuntable
  • Black matt paint for background

Home made light tent

It’s pretty easy to put together. Tape the box closed, then cut holes out of the front, top, left and right sides. Tape the tracing paper over the top, left and right sides. Paint the back of the box black and you’re done!

This results in even light around the subject when used in conjunction with a macro ring flash for the front light source as shown in the photo below …

macro bone skull broken

This is a great improvement over my previous setup..

Photogrammetry Setup

With the addition of a tripod and macro rail, I’m now all set up ready to take more and more photogrammetry shots.

Elephant Drawning

Drawing an Elephant – It’s going to take how long ?!

I was so pleased with my Cheetah drawing, I went straight into the next one without thinking too much. I had gotten into a groove doing fur textures with lots of small brush strokes in the same direction. It was all about following the flow of the body. As soon as I started this elephant drawing I knew I had taken on an entirely different beast and there was no going back!

Based off another excellent photo by Mike Haworth from howieswildlifeimages.com I could see so much opportunity in the texture and lighting that I wanted to express.

I used the picture as a base layer in Photoshop, so I could check my initial sketch wasn’t too off. Personally, I don’t like to trace directly over a picture and I feel it loses some of it’s spirit in translation when I do. In this case, I had it as a back up for when I got lost in marker placement and proportions and used it as a guide to get back on track.

I continued to number my sketches ### of 366 as a reminder that I was planning to sketch every day. The initial sketch above was 030 of 366. Starting with the eyes (well, one eye) the initial progress was fine and I developed a criss-cross technique for filling in detail on the trunk ..

I soon realised while filling in that dark area under the eye that when it came to the ears, I would need to try something different. A simple pencil brush was not going to get the detail and texture I wanted without getting too scratchy. I had been collecting ImagineFX magazine for a while and have accumulated quite a range of Photoshop brushes over time. One particular set from artist Saejin Oh – https://saejinoh.blogspot.co.uk/2014/09/jinbrush-2014.html is really nice and has a good range of different textures I wanted to play with.

After a bit of freestyle experimentation, I was able to block out the ears very quickly by comparison with the other details ..

We are now at 40 of 366 by the way. The rest was a continuation of my pencil technique, noodling details while getting a feel for the wrinkles, textures and lighting as I drew. Another 18 sessions later and I had finally completed 058 of 366 …

I’m really happy with how he turned out, especially once I balanced some lighting and contrast at the end. I’m planning on doing the same as I did with the Cheetah and mount a print of him onto wood.

The sad part is that even though it is 50/366, I never did any more drawings for 2016. Various aspects of life/work and a change of home meant drawing took more of a back seat for the rest of the year (by back seat I mean forgotten). Will I draw again in 2017? Almost certainly! Mixed in with photogrammetry and whatever other projects I have time for. Until then, here is a timelapse of the entire 12 hours condensed into 12 minutes!

 

Romanesco Broccoli Photogrammetry

Romanesco Broccoli

Romanesco Broccoli – A Tale of Two Halves in Photogrammetry

I recently took part in a challenge set by the Sketchfab community to use photogrammetry to scan in a piece of fruit or vegetable to put in a 3D Cornucopia, more comonly known as the Horn of Plenty. I chose to scan a Romanesco Broccoli because it is complex, and interesting while still an easy shape for photogrammetry to pick up – at least so I thought!

I wanted to capture the whole veg which meant taking 2 sets of photos, one from the top and the other with the broccoli turned over to show the underside.

I used a newspaper base to rest the broccoli on which is extremely helpful to the photogrammetry software in working out camera alignment. The broccoli itself, while detailed, is also very regular which makes it hard to pick out unique features.

For this scan, I was able to borrow a Canon 7D camera which gave me a whopping 24 Megapixels to play with rather than my usual 6! I used the same lens though (my kit 18-55mm), so the gains were not as great as could be with decent glass.

No focus stacking was done for this shoot and I used natural light and a ring flash. The camera was also mounted on a sturdy tripod, rather than my usual ghetto lego balancing act.

The resulting photos were very detailed and clean but on close inspection a little soft which I mainly blame the lens for.

ISO was set to 100, Shutter speed was 1/5 sec. and F-stop was f/13.

I have made the photos available to the public for on Dropbox here .. Dropbox Download Be warned, it’s a fairly large 448MB download!

Agisoft Photoscan

With all my 95 shots taken, it’s time to go into Agisoft Photoscan and see how it gets on…

Firstly, I tried without any masking to see how it gets on with camera alignment straight from the can. The resulting alignment was a little off and I could see it straying in the point cloud. This was probably down to the background throwing off the alignment.

Next, I manually masked out the background in every shot to tell Photoscan to focus on the foreground and include the good bits of newspaper print.

This gave me decent alignment of all cameras and an accurate looking cloud of points…

Once all the dense cloud and mesh generation was complete, my first thought was to do the mesh alignment in Zbrush and combine them there. I don’t know why I didn’t try it in Agisoft first, perhaps it was unfamiliarity of how best to go about it and I was at least familiar with Zbrush.

Unfortunately, the route into Zbrush proved no good. I spent a lot of time cleaning and aligning each half manually, but when it came to dynameshing, Zbrush crashed constantly and I couldn’t get a clean re-projection. I abandoned the Zbrush route and researched how I should have done it in the first place.. inside Agisoft.

Normally, you would let the software try to align the point clouds itself, but due to the fractal nature of the broccoli and the fact I didn’t have a lot of overlap in my meshes, it could not get an alignment without the newspaper. I decide to use a 2 step process using markers. First I picked out 4 points along the edge to allow the software to align the 2 chunks pretty closely. Then, by flipping between the 2, I was able to more accurately plot some more markers at various points around the rim…

From here, alignment was more accurate and I was able to re-generate a mesh from the 2 dense point clouds with a fair amount of accuracy. I then decimated the mesh to a more CPU friendly 700,000 faces rather than the original 14 million!

I wanted to try some nice rendering techniques, so took the model into Maya by Autodesk. I’ve been using this package professionally since it was Alias Wavefront, so am totally happy using it. The decimated geometry was fine to use as it was. The place I wanted to work a little further was in the texture. I wanted to use a sub surface scattering shader in my render, so needed to do a little work on the texture in Photoshop first. I used the colour to create 2 additional textures to represent the deeper layers of colour..

The resulting render looked like this ..

Romanesco Broccoli

I did a turntable render too …

.. and you can see the final model and download it in Sketchfab here …

Overall I was pretty pleased with how it turned out. I learned loads about combining two sets of scans into one mesh and the pitfalls involved. In hindsight, I’d allow for more overlap in the meshes and paint some small bright dots on the broccoli, so I could align more easily. A Romanesco Broccoli is too fractally (made up word) to be able to pick out unique features.

All the best – Stu

Cheetah Sketch

Cheetah Drawing Framed on Canvas

Last year, I decided up up my game with digital sketching and spend more time on a single picture ramping up the detail as much as my tablet would handle.

I found some beautiful African animal photos on Mike Haworth’s site – https://howieswildlifeimages.com/ and asked his permission to use his photos which he kindly agreed to.

It’s rare for photographers to make such high resolution images available on the net, so this picture could be cropped to a closer framing while still keeping enough detail to use as reference.

Once cropped to a framing I liked, I did a quick sketch to get proportions correct and a basic layout of features..

Cheetah rough sketch

I can then use this as my base layer in Photoshop and start noodling the detail. This step takes the longest! Starting with the eyes and using the photo side by side as reference, I worked my way around following the flow of fur and adding details over several sessions on my commute to work.

Cheetah sketch WIP

The main brush I use is a 4 pixel pencil brush and hundreds and thousands of little strokes later I get this …

Cheetah Sketch

All in all, it took about 20 sessions and 9 hours to get to this point. The final image is 3508 pixels by 4961 pixels which is A3 size at 300 dpi

I did a timelapse video of the entire process which you can see here …

However, this is not the end of this particular journey. I wanted an actual print so I sent off my digital sketch to be printed on 12″ x 16″ canvas. I was very pleased with the result from http://www.justrolledprints.co.uk , they provide an excellent and reasonable service – highly recommended.

The next stage was to construct a frame.. I put together several pieces of wood salvaged from the beach, cut to size and sanded down the face, filled the gaps and varnished it..

Wooden Picture Frame

The final touch was to stipple oil paint around the sketch directly on the canvas to match the tone of the varnish and glue the final piece onto the front. Here is the final result …

Cheetah Drawing Framed on Canvas

and here is mounted on my wall at home ..

I plan on doing many more of these kind of pictures, perhaps into a series of African wildlife.

Focus Stacked Reverse Lens Macro Photogrammetry

Introduction

Well that title is a mouthful! I’d like to talk about Photogrammetry. This is a technique to construct 3D models from a series of photographs. My particular take on it is to do this with small objects like a Hamster Skull! Hence the phrase Macro Photogrammetry. Now I don’t have a lot of money for this, so to do cheap Macro Photography, you can put the lens on your camera back to front with the help of an adaptor ring, now we get Reverse Lens Macro Photogrammetry. The problem with macro photography is you get a very shallow depth of field, so here comes the technique of Focus Stacking! Focus stacking means taking a series of photos in exactly the same place, but changing the point of focus slightly in each photo. You can then combine the photos in a program which takes the sharp bits of each photo and blends them together into one image and that’s how we get to Focus Stacked Reverse Lens Macro Photogrammetry!!

campbells-dwarf-hamster-phodopus-campbelli-skull

Hammie’s head is tiny! His skull measures a mere 28mm long. He also has some really challenging details such as thin pieces and deep sockets, so he will be a good test of the process.

Let’s look at each aspect in detail..

The Photogrammetry Process

Photogrammetry at its core is making 3D objects from 2D photos. It uses complex maths that I won’t even pretend to understand, but if you can get your head around what the program needs, you can supply it with good quality photos that yield accurate results (and look awesome).

How does it work?

You give the photogrammetry program a photo of something. It looks at the entire image not knowing what it is at all, what the program is looking for are details it can match with other photos. These will be areas of pixels which have high contrast or unique patterns.

photogrammetry details

It will look for thousands of details like the ones above ..

Photogrammetry trim point from agisof photoscan

As you can see, it will look for points even in blurred areas and this is where errors can creep in. It is a good idea to either mask off the blurred areas or eliminate them in the first place.

Once it’s analyzed all the photos for matching details, the program then tries to work out where the camera was when each photo was taken. If will use EXIF data such as focal length from the photo to help with the calculation if it can. You can even supply calibrated camera data that has been pre-calculated beforehand.

Here is what a camera aligned screenshot looks like …

Agisoft PhotoScan Aligned Cameras

Once you have the aligned cameras, the program can then use this information to go back through the photos and look at finer details and cross-compare with others to generate a dense point cloud in 3D space. This cloud of points can then be used to generate a 3D model comprised of many vertices and faces (in the order of millions for some objects). Then you can project the photos back onto the model to give it texture (colour detail). I’ll go into more detail on the steps within Agisoft Photoscan later.

The end result is a 3D model you can edit, rotate, analyse from every angle or even 3D print it out!

Equipment Needed

So what do you need? – a camera, obvs. That’s it really, you can use any camera, your phone etc., but the end result is entirely dependent on the photos you take, so there is a little more equipment that will go a long way to helping the process..

I’m doing this on the cheap, so my choices are based on what I have already or can get at a reasonable price..

Camera – I’m using my old Canon 300D DSLR I’ve had for 13 years. It cost £700 at the time, but you can pick one up second hand for less than £50 these days. I wouldn’t recommend it as it’s only 6 megapixels, but as a DSLR I have a lot of control over shot settings and lens choice. For photogrammetry, megapixels do matter but so does sensor size, so go for the best you can afford. These things get pretty expensive fast!

Lens – I’m using the 18-55mm kit lens that came with my camera. For sharpness, I’d recommend a prime lens (fixed focal length) a 50mm prime would work for most. For macro, I’d go for Canon’s 100mm Macro lens. Again, money is a big factor here.

Remote Trigger – In order to minimize vibrations, it’s really handy to have some sort of means to be able to press the trigger without touching the camera. A cable release is simple and effective if your camera supports it. You will be taking a LOT of photos, so it needs to be accessible. I bought a cheap one for £4.48 from Amazon, here is a link (opens in new tab) – Amazon – Remote Shutter Cable

Reverse Lens Adapter – For cheap macro, you need an adapter ring that screws onto the filter thread of your lens and allows you to mount it in reverse I got mine from Amazon for £7.19, here is a link to it – Amazon – Reverse Lens Adaptor Ring

Lighting – The more even, diffuse lighting you can get around your subject the better as it will avoid harsh changes in shadows as you rotate the subject which will throw off the photogrammetry. I used a couple of desk lamps to set the main lighting either side of the subject. What really helps here is a ring flash as that will boost the light straight from the lens and helps get rid of shadows. Again, I’ve gone for the el cheapo option which works well enough for my purposes. Amazon to the rescue again! – I got mine for £21.11 – Amazon – Macro Ring Flash

Note: All these Amazon links above are affiliate links, which means I get a little bit of money if you buy anything from Amazon after clicking the links. Better you know up front.

Turntable – You need to be able to smoothly rotate your subject without knocking it in order to cover every angle. I’ve gone for two options here. The first is a Lazy Susan we had in the house already which works great for larger specimens. The second is a bit more custom as I made it out of my sons Lego. The Lego version rotates sideways like a lathe which is really handy for getting all angles with the camera. You have to remember to rotate the final photos by 90 degrees before putting them through the photogrammetry software though as it assumes you are moving around the subject in the up/down axis.

Photogrammetry Setup

Tripod – It is essential your camera is steady while taking shots, so a worthwhile investment is a sturdy tripod. However, as I’m going cheap again. I built a base from more stolen Lego (sorry son) and an elastic band to hold the camera steady. It works well for the lathe orientation as the camera only needs to move from side to side. If using the Lazy Susan rotation, a tripod would be preferable (although I did manage it with a Lego tilt mechanism)

Total cost so far (at todays price for camera) – £82.78

Software

There are a few free photogrammetry programs out there (VisualSFM + Meshlab, Autodesk 123D Catch). However, none come close to Agisoft Photoscan – http://www.agisoft.com/ It really is the best and most easy to use for the price. It has a 30 day trial and currently costs – £144 at Brexit exchange prices.

If you are going to do Focus Stacking, then I’d recommend Helicon Focus – http://www.heliconsoft.com/ It does a great job, better than Photoshop and is really fast too. Current price is – £24 for a 1-year license or £92 for unlimited

Computer

I’m also assuming you have access to a computer to do this all on. A fast CPU, lots of memory and a good graphics card will all help speed up the process. I’ve tried it on a £300 home built PC and a £7k beast, the more you spend, the faster things get processed.

Workflow overview

Right, so you’ve got this far. You have your camera, computer and software. Now what? Well you need something to capture. I’m focusing on bones at the moment because my eventual aim is to scan in an entire skeleton and re-articulate it in 3D and animate it. Bones are also ideal because they are not shiny or hairy or leafy or made of glass or metal or plastic or alive and moving – all of which are hard to capture using photogrammetry. You also want something with a lot of surface detail or colour variation as smooth surfaces are also difficult to capture.

Once you’ve decided on an object, you want to mount it so it rotates about it’s longest axis showing as much of the entire object as you can without it falling over. I use Blu-tak to hold non-precious (and light) subjects in place. Bear in mind you may need to capture the object in two or more orientations and merge the meshes together later.

Think also about the background, it will ideally be plain and a different colour to the subject. Also useful is some sort of base plate like newspaper or irregularly patterned matt surface which can provide some really helpful key points for the software to lock on to.

Taking the pictures

Once you’ve got your subject chosen and ready, it’s time to go through a few settings in readiness for your photo session..

Camera Settings

So, your camera needs to capture the image with as little noise or blurriness as possible. In photography, there is the holy triangle of ISO, F-Stop and Shutter speed which result in a perfectly exposed picture. We need to control each of these to get to that lovely exposed picture with minimal blur or noise. Everything will be manual, so expect a few test shots to get the right settings.

ISO – set to the lowest you can for your camera, usually 50 or 100. Lower means less noise = good for photogrammetry.

F-Stop / Aperture – The higher the number, the greater the range of depth of field, so the more of the subject is in focus. Sounds great to go for the highest you can, right? Unfortunately, there is also this thing called diffraction. The smaller the aperture (higher F-Stop number), the more like a pinhole the lens gets until it gets to a point where everything is a little bit blurry like trying to look through scrunched up eyes. A good general rule of thumb to avoid diffraction is about F11 to F16

Shutter speed – The last thing in the holy triangle you have some control over to get the right exposure! Unfortunately as the other two are at their worst setting for getting light onto the sensor in favour of sharpness, the shutter speed is going to be quite long. This is why everything must be solid and still. You can help this by getting more light on the subject, but more on that later.

Try some test shots at different angles to get the right shutter speed for best exposure. Use the histogram feature! Avoid too much contrast or burnt out highlights.

White Balance – If your lighting and subject matter colour is consistent, you can get away with leaving this on automatic. Otherwise fix it to a sensible temperature setting that works for most angles.

RAW or Jpeg – Normally, I’d recommend shooting RAW because Jpeg will introduce compression artifacts. I chose to shoot Jpeg for practical reasons of space and speed of capture, just make sure it’s on it’s highest setting. Shoot RAW if you can.

Focus – Set to manual and adjust for each shot to get as much in focus as you can. If you are going to focus stack, you’ll be taking several shots at different focus points.

Lighting

Ideally you’ll have some good natural white photography lights shone through a diffuser to give your scene a bright, even light. However, I’m using what I have to hand so a couple of desk lights will have to do. Position one on each side of your subject, if you have a third you can shine overhead, even better. If the lights are bright enough, shine them through a piece of tracing paper or tissue paper which will help diffuse the direct light. Or you can point the light in the opposite direction and bounce it off some white card. There are many ways you can set this up, but the minimum is two light sources either side and preferably a ring flash.

The ring flash will be your key light source as it will give a much needed boost at picture taking time. If you have the battery power, some ring flashes can be set to continuous light mode. The great thing about the ring flash is the light is even all the way around the lens and really helps remove shadows. As my lens is reverse mounted, the ring flash can’t screw onto the lens filter, so I had to stick it on with blu-tak.

Another option is a bright, overcast day and shoot outdoors, but bear in mind clouds can cause subtle variations you cannot control.

Stability

Any knocks, vibrations or movement are going to result in blurry photos which are useless for photogrammetry. Make sure your camera is on a sturdy base (even if it’s made of Lego). Use the cable release. If your camera has a mirror lock up feature, use that to reduce shutter vibrations. Don’t leave your hand on the turntable or anywhere where you breathing is going to cause things to move (the subject or the camera). Remember your shutter speeds are likely to be long, so vibrations get magnified.

Rotating

Think about the process of taking the photos, it’s best done in one big session with the lights consistent. First, position the camera side on and square to the subject. Take your shot. Rotate subject 5-10 degrees, take another shot. Repeat until you’ve done a whole 360 degree rotation. Then move the camera to a new angle and repeat. Do this for as many angles as to cover all nooks and crannies

Focus Stacking

If you are going to the added effort of focus stacking, when you set up each shot start with your point of focus at the farthest point behind the subject then after each shot, focus slightly further forward. Try to overlap the points of focus to get as much coverage as possible. Once, you’ve done a full set of focus point, then rotate and do it all again! And again! And again!

Here is an example of an entire photo shoot including focus stacking …

Processing the Photos

Focus stacking

This technique really helps gets maximum detail out of your macro shots, but at the cost of adding another layer of processing which risks losing valuable lens information that can be used by the photogrammetry program.

I’m using Helicon focus stack on default settings as it seems to work well with minimal fuss. All my source photos are in one folder, I manually select each batch of photos from the folder and drag it into Helicon for processing. Any photos which are under exposed are not included for processing, you can see them appear in the video above where the flash has failed to fire.

They have a great tutorial on the workflow on their site – http://www.heliconsoft.com/helicon-focus-workflow/

Once stacked, you should have a clean set of photos ready for the next step.

Image adjustment / Rotation

The way I rotated this particular skull is set perpendicular to the ground like a lathe. While this makes it more convenient for camera placement and accessibility, it breaks some basic assumptions that the photogrammetry program makes about orientation. In order to fix this, you need to rotate all your images 90 degrees to pretend the object is static and you are moving around the subject with your camera at 90 degrees (portrait) which is the basic assumption the photogrammetry program is making.

If your photos are slightly under exposed, you can lift out some of the details by applying some careful basic adjustments like levels. However, bear in mind you are adding another layer of processing that might confuse the photogrammetry program. If you do decide to make adjustments, make sure the same amount is done on every photo to maintain consistency.

Masking

Another useful step is to mask out any background that you don’t want included. This can be done from inside Agisoft Photoscan, but if you have access to a program like Photoshop, you can automate the process especially if your background was a consistent colour not used elsewhere like a green screen.

For my example, I chose not to mask the background.

Agisoft Photoscan Workflow

Now that we have done the hard work of getting the best source photos we can, here is where the nitty gritty of generating a mesh comes in and (hopefully) the hard work will pay off!

First step is to import all our clean photos using Add Photos in the Workflow menu.

Then we need to mask the background of each photo using the in-built selection tools to define areas to ignore. This step can sometimes be skipped if you have a clean background.

Next is to align the photos, this is where PhotoScan works out where each camera is and creates a sparse cloud of points to represent the mesh. This stage is where you can tell if your source photos are any good for the program. The default settings should be sufficient, but if you have the PC power, it can be useful to up them by a factor of 10. Turn on constrain features by mask if you have masked out the background in each photo.

Once done, have a good look around the mesh cloud to see if it looks like the object you captured. You can tell if it’s getting mis-aligned as it will look less defined than you expected (or even inside out or overlapping). You can also look at the camera placement and you should have a clear idea if it looks right or not. There is not a great deal you can do about it other than take photos again using a different base plate, orientation or lighting or it could be down to the object itself. Sometimes changing settings or masking can help, but not always.

Agisoft PhotoScan Photo Alignment Wide

You can clean up an alignment after by selecting any points that are clearly in the wrong place and deleting them. It can also help to do a Gradual Selection from the Edit menu using default Reprojection Error settings and delete the selected points. Then do an Optimize Cameras in the Tools menu to refine stray points and resulting calibration.

Once you are happy that everything looks ok, it is time to build the Dense Cloud. This process looks in finer detail at every aligned photo and uses the newly worked out camera data to calculate what the actual mesh looks like. Before you build the Dense Cloud, check the position and size of the bounding box, so that incorporates the whole mesh. If you have a fast enough PC with enough memory (try it and see to guage if you have), use Ultra High settings as it will take the maximum resolution of photos as reference.

The remaining steps are to build the mesh and generate the texture. These are fairly self explanatory. Once the mesh is generated, you get a real sense of which parts worked and which didn’t …

Agisoft Photoscan Dense Cloud Mesh Textured

 

Results!

After all that, we can view the mesh and examine all the lovely detail with any luck. I am somewhat happy with the results of my example skull. You can see the overall shape and detail. There are holes in the mesh where there were not enough overlapping photos, especially near the base. If I were to re-shoot, I’d use a slightly smaller base plate, so I can get in closer.

The grain you see all over the mesh is most likely due to my camera being so old and low resolution, I’d love to try it on a better camera next, but the expense is going to escalate fast.

I’ve uploaded my model to Sketchfab, so you can take a closer look yourself …

Sketchfab Model of Hamster Skull

Click link to go to Sketchfab Model -> https://skfb.ly/XH7O

Summary

On the whole, I’ve learned a lot just to get this far with my example. Hopefully, my ramblings will help others take their own models further.

The only things I’ve not done with this example is to create a second version capturing the skull from a different base, which I can then combine the two meshes and remove both bases. I’d also take this into a 3D modelling package like Zbrush to clean up and optimize further, but maybe another time!

Future work will involve trying to get hold of a better camera and decent macro lens. These I believe would vastly increase my detail and help eliminate noise.

Further reading

If you’d like to learn more from various other sites on the web, here are a few I have visited to gain my knowledge so far…

This fantastic video series on using Agisoft Photoscan and merging 2 meshes together…

Great PDF and blog on techniques for Photogrammetry – https://dinosaurpalaeo.wordpress.com/

Posts by Stu Pond on Photogrammetry – http://paleoillustrata.blogspot.co.uk/

Some great articles by Dr. Peter Falkingham on free Photogrammetry software – https://pfalkingham.wordpress.com/2016/09/14/trying-all-the-free-photogrammetry/

Paper about using Focus Stacking and Photogrammetry – http://zookeys.pensoft.net/articles.php?id=4346&display_type=element&element_type=4&element_id=411&element_name=

Paper about using automated system for capturing photos – http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0094346

 

That’s it and have fun! If you have any questions or comments, please do get in touch.

Stu

Giraffe sketch live

Giraffe sketch

I had the good fortune to pay a visit to Marwell Zoo. Naturally, I took along my trusty Wacom Companion for a spot of live sketching. My chosen subject for the day was the Graffes. They have a fantastic enclosure at Marwell with lots of space and a warm shelter. Luckily, they were all inside feeding at the time.

I approached the edge and got into position. No sooner had I got there, one giraffe came right over to me and leaned over the fence right up to my face! I stroked her nose and she licked my hand, nearly getting my Wacom pen with her prehensile tongue!

With formal introductions made, I started to sketch for 45 minutes. I did not focus on one particular giraffe, but rather took in all their general details as they moved around. Sketching live animals is much harder than using photos. You have to constantly observe and work fast, going back to areas once the opportunity arises.

Here is the result …

Giraffe sketch
Live drawing of the giraffes at Marwell Zoo

I also put together a video timelapse of the entire process, so you can see how I worked into the details after a loose initial sketch…

Pet Portraits

Pet Portrait of Bessie the Dog

I’ve been refining my sketching process and this is the latest result .. a pencil sketch of my beloved pet dog, Bessie ..

Pet Portrait of Bessie the Dog

I am available for commissions if you would like a sketch of your pet as a portrait either in digital format or printed and framed. Please get in touch via email (stu@hogton.com) to discuss your requirements and prices.

Many thanks,

Stu

Giraffe Sketch Timelapse

Giraffe

Back in the game for #dailysketch as I’ve been a bit sporadic these past 3 weeks due to lots of stuff going on and burning the candle at both ends. Typically I’ve been falling asleep on the train rather than sketching.

Today, I completed my Giraffe sketch ..

Giraffe
Giraffe Sketch

.. and if course a Timelapse on YouTube ..

60 Days of Sketching

Sketch every day for a month

60 Days ago I made a commitment to sketch every day. I set very loose targets, I didn’t tell myself how long for or what subject, I just had to make sure I sketched something. This was made easier because I had just got hold of a Wacom Companion 2 and like anyone with a new toy, I was itching to try it out.

This was day 1 ..

Viking concept sketch
Day 1 of #dailysketch

.. and this is day 60 ..

Amur Tiger
Amur Tiger

I think the results speak for themselves! I quickly realised I had forgotten how much I loved drawing animals and that set the theme for most of my drawings. Most were started and finished in one session, usually on the train on my way to work. Some I spent a bit more time on, the Tiger being the longest as it took 10 days of sketching to finish it.

Here is a YouTube video of all the sketches one after another ..

That represents about 40 hours of my time spread over 60 days. Doesn’t sound much does it? Anyone can do it and I bet you’ll see results after 30 days, let alone 60. Those 40 hours could’ve easily been spent playing Skyrim or Civilization or watching films. I made a concious choice to make sure nothing like that was on the Wacom Companion to distract me. I am a terrible procrastinator. I have been avoiding doing this for 15 years! Living in fear of my own art. It is liberating to finally be creating rather than consuming. I suggest you all try it for 60 days.

Amur Tiger Timelapse Sketch

Amur Tiger over 10 days

I love drawing big cats, and to celebrate sketching every day for 60 days, I spent the last 10 days working on this Amur Tiger from a picture I took at Marwell Zoo back in 2006.

Amur Tiger over 10 days
10 Days of Tiger Sketching

.. and the final result ..

Amur Tiger
Amur Tiger

I also recorded a timelapse of the entire sketching process which you can see on YouTube …