2009-12-31

Short manual slider

Winter Solitude from Martin Koch on Vimeo.

How long should your slider be? I bet in 99% of all cases you'll just need a short one. Consider this. A rather common 10 mm/s move uses up 100 mm rail per film second. You'll be able to show a pretty long 40 seconds move with a 500 mm rail and 100 mm carriage. In practise the majority of your dolly moves will be under 10 seconds long so a 500 mm rail will be more than sufficient.

The following is a version of the "ZaZa" Slider described in this great dvxuser thread.

My new short manual slider consists of:

  • One 500 mm long Igus DryLin W WS-16-60 rail.
  • One 150 mm long WW-16-60-15 HKA carriage with manual clamp.
  • One cheap Velbon PH-368 fluid head.
  • One Manfrotto 357 universal sliding plate for quickly mounting the slider to a tripod.
  • Two blocks of wood for low slider moves.
  • Four M10 or 3/8" bolts with washers for the end stops.
  • One 3/8" or 1/4" bolt for mounting the fluid head.

A 100 mm long carriage would be more than enough but I had to choose the 150 mm long carriage because the manual clamp doesn't fit on the short carriage. Nevertheless I still can do more than 30 seconds of slow 10 mm/s moves. Plenty enough for me.

The total cost for the complete manual slider is 220 EUR incl. VAT (120 EUR for the Igus parts + 40 EUR for the fluid head + 50 EUR for the universal sliding plate + 10 EUR for small parts). Please note that Igus seems to have different prices for different countries so your total costs can vary from mine. The whole assembly is heavy, rock solid and will work with much larger camcorders than the HF100.

The 8 mm diameter holes in the 16 mm diameter rails are perfect for a 3/8" thread and nearly perfect for a 10 mm thread. I bought the 3/8" UNC tap and 3/8" UNC bolts from RS-Components. Single 3/8" UNC bolts are available from Rosentaler-Schrauben.at.

Smooth manual slider moves are not hard to do after some practise. Nevertheless I couldn't help to try an enviroment friendly, absolutely silent, gravity driven automatic slider version. I bought the rope roll with ball bearings (pulley) some time ago from eBay. I suggest you do a Google product search for possible suppliers.


video

As it turns out this is also useable to add movement to shorter timelapse shoots. 0.3 mm/s are no problem.

Optional with larger equipment a block and tackle system could save weight.

Without deflection of the rope you can go as low as table height with this system

2009-12-21

Canon BP-827 Fully Decoded Compatible Battery

This 2900 mAh third party battery is fully compatible with the HF100 and other Canon cameras i.e. It can be charged in the camera or with the original Canon charger and it shows the battery level on the camcorder display. This battery will power the HF100 three times longer than the battery that came with it.

The original Canon BP-827 battery currently has a street price of $125 / 120 EUR.

2009-07-09

DIY camera motion control

Hows about moving your HF100 like a pro?

DIY camera motion control from Martin Koch on Vimeo.
The system consists of a ready-made IGUS DryLin W rail system and a small stepping motor which is controlled by an Arduino interface board. Once the controller program is loaded the system works stand alone. It can be powered by a battery and can be controlled by a simple power switch because the programmed task starts automatically each time the Arduino board is powered on. It's possible to horizontally move loads (camera + mounting head) of up to 6 kg (13 lbs) with the system described below.
Here's what you need:

Slider

1000 mm long Igus DryLin WS 10-80 rail.
Costs: about 50 EUR / m
Ready-mounted Igus DryLin WW 10-80-15 sledge.
Costs: about 30 EUR
The maximal possible length of movement equals rail length minus slider length (the WW 10-80-15 sledge is 150 mm long) so the usable length will be 850 mm ( 1000 mm - 150 mm).

The Igus order number for a complete system with 1 meter long rail and 150 mm sledge is WK-10-80-15-01, 1000 (the first number is the rail diameter in millimeters, second is the rail width followed by length of sledge, number of sledges and rail length).
The DryLin-W railsystem is a maintainance free, self lubricating linear guide system. It is available in three rail diameters: 10, 16 and 20 mm.

Official Igus procedure for aligning the carriage (needs to be done once).
1. Loosen all carriage bolts - (don't remove - just loosen a few turns)
2. slide carriage back and forth to allow bearings to align themselves
3. Tap the center of the carriage to "bump" the bearings into place
4. With downward pressure on carriage tighten the bolts again a few turns at a time (alternating them - i.e. do NOT crank one down and then do the other ones)

Alternatively you could also use the narrower 10-40 system but the savings are minimal. Or for a super strong version for long rails or cameras that weigh more than 3 kg (1.5 lb) use the 16-60 system. Read this thread at dvxuser.com for more info and inspiration. (a 10-40 version is shown in post #336 on page 34). Post #475 shows how to move along an arc.
You can order directly from Igus. They have offices around the world. More info at Drylin-W.de
This is about all you need when you move the camera manually. You can also build a hand cranked version if you wish. I went a step further and motorized the whole assembly.

Controller board

Arduino Duemilanove (or Arduino Uno see update below) or Arduino Nano USB I/O controller board. Visit arduino.cc for more information and where to buy it.
Costs: Arduino about 25 EUR, Arduino Nano about 50 EUR.
The current (as of 2009) Arduino is called Duemilanove which is italian for "2009". It is meant to be used with a "shield", an interface board that sits on top of the Arduino.

I used the Arduino Nano. It offers the same features in a smaller 30 pin package that can be used just like an integrated circuit. You need an USB to USB mini cable to program it. Such a cable came much likely with your digital camera.

Software

Download and install the Arduino software for Windows, Mac OS X or Linux.
Costs: free.
Copy and paste the following Arduino sketch into the developing enviroment and download it to the board. Make sure to choose the correct board under Tools>Hardware. If you use an Arduino Nano replace the digital output numbers with the ones in the comment. Once downloaded the Arduino executes the sketch on its own. Every time power is turned on or the tiny reset button is pressed the sketch starts.
/*
Move an unipolar stepper motor
Version 2.0 with simpler, leaner code
2010, Martin Koch
http://canon-hf100.blogspot.com/
----------------------------------------

Use a 12 V, 0.16 A to 0.5 A unipolar (6 wires) stepper motor

If you use the Arduino Nano assign these digital output numbers:
#define D0 2
#define D1 3
#define D2 4
#define D3 5
*/

// Arduino digital output numbers
#define D0 13
#define D1 12
#define D2 11
#define D3 10

int rpm = 30; //revolutions per minute (keep below 100)

void setup() { 
 pinMode(D0, OUTPUT);
 pinMode(D1, OUTPUT);
 pinMode(D2, OUTPUT);
 pinMode(D3, OUTPUT);
 delay(1000);

//Choose number of steps by trial and error 
//so the slide runs the whole length of the DryLin W rail
 for (int step=0; step<9000; step++) {
   moveMotor(step); 
   delay (150 / rpm);
 }
 motorOff();
}

void loop() { 
// run again and again (not used)
}

void moveMotor(int step) {
 switch (step % 8) // Half steps (step modulo 8 ensures 0 to 7 cycles)
 {
  case 0:   //1000
  digitalWrite(D0, HIGH);
  digitalWrite(D1, LOW);
  digitalWrite(D2, LOW);
  digitalWrite(D3, LOW);
  break;
  
  case 1:    //1100
  digitalWrite(D0, HIGH);
  digitalWrite(D1, HIGH);
  digitalWrite(D2, LOW);
  digitalWrite(D3, LOW);
  break;
  
  case 2:    //0100
  digitalWrite(D0, LOW);
  digitalWrite(D1, HIGH);
  digitalWrite(D2, LOW);
  digitalWrite(D3, LOW);
  break;
  
  case 3:    //0110
  digitalWrite(D0, LOW);
  digitalWrite(D1, HIGH);
  digitalWrite(D2, HIGH);
  digitalWrite(D3, LOW);
  break;

  case 4:   //0010
  digitalWrite(D0, LOW);
  digitalWrite(D1, LOW);
  digitalWrite(D2, HIGH);
  digitalWrite(D3, LOW);
  break;
  
  case 5:    //0011
  digitalWrite(D0, LOW);
  digitalWrite(D1, LOW);
  digitalWrite(D2, HIGH);
  digitalWrite(D3, HIGH);
  break;
  
  case 6:    //0001
  digitalWrite(D0, LOW);
  digitalWrite(D1, LOW);
  digitalWrite(D2, LOW);
  digitalWrite(D3, HIGH);
  break;
  
  case 7:    //1001
  digitalWrite(D0, HIGH);
  digitalWrite(D1, LOW);
  digitalWrite(D2, LOW);
  digitalWrite(D3, HIGH);
  break;
 } 
 return;
}

void  motorOff() {
   digitalWrite(D0, LOW);
   digitalWrite(D1, LOW);
   digitalWrite(D2, LOW);
   digitalWrite(D3, LOW);
}
There's also an Arduino stepper motor class available but I prefered to write my own stepping motor control code just for fun. To cut noise the motor is operated in half step mode so it doesn't offer the full torque but the ULN2803A interface allows to connect twice as strong motors.

Stepping motor

Small 12V unipolar (6 wires) stepping motor with maximal 0.5 A per winding.
Costs: about 30 EUR.

My stepping motor needs just 0.16 A per winding and offers a force of just 70 mNm (0.070 Nm = 0.62 Pound-force inches). Nonetheless it is still able to horizontally pull loads up to 6 kg (3 lb). I bought it from RS-Components. The part number is 440-436. In order to fit my interface I had to rearrange the wires. To loosen a wire in the type of connector shown above use a needle to press in the latch from the front then pull out the wire. The wire easily clicks in place at the new location. If you use the same motor the wire arrangement in the plug should be B brown, E brown, A white, F blue, C red, D yellow.

Interface

1 ULN2803A integrated circuit, prototyping board, connection pins, wire
Costs: A few Euros.
The interface is as simple as it can get. Make sure to connect the stepping motor wires as shown in the schematic.
Schematic for Arduino board

Schematic for Arduino Nano board


This board also shows a 5 V relais (orange part) that is used to trigger a still camera.

Battery

A small maintainance-free 12 V lead battery with about 2 Ah is inexpensive and sufficient for hours of continuous operation.
Costs: about 20 EUR.

You'll also need a lead battery charger

Assembly

The most silent solution is to use a nylon rope to pull the sledge across the track. It works in one direction only but by turning the whole assembly by 180° its easily possible to move in the opposite direction.
The usual camera move is from left to right just as we read. It tells the viewer that everything is alright. If you want to disturb the viewer move the camera from right to left.

The rope bobbin can be made on a lathe.

The whole assembly is not completly silent but silent enough to be usable. The noise of the stepper motor is cut significantly by using rubber mounting bolts.

Ideas

If you don't mind the noise (e.g. music video) you can also use a d.c. motor with gear assembly. The Arduino board offers pulse width modulation (PWM) control to set different speeds.
The Arduino board also offers analog and digital inputs so you can wire a potentiometer or switches to set different speeds.
The possibilities are endless and it's fun to play with the Arduino system. I recommend the book "Getting started with Arduino" for an easy start.
Here's an example video: vimeo.com/5535135

Update March 9, 2010: I updated the Arduino sketch above with a simpler and leaner version that does the same.
Update November 20, 2010: There's a new Arduino UNO available which replaces the Arduino Duemilanove and works the same.
Update February 15, 2011: If you use the Arduino UNO it's best to built the interface circuit on a ProtoShield that can be plugged directly into the Arduino.
Update June 19, 2011: As far as I know Igus doesn't sell directly to individuals any longer but they offer ready-made sliders with predrilled 3/8" hole at Amazon.com.

The image from Amazon above shows that you need 8 bolts to properly fasten the plate to the four linear bearings.

Do you want an even leaner code? Well I recently learned how to use the Arduino stepper library with an unipolar stepper motor. It's way simpler to use than I thought and although I haven't tested the code below I post it to give you an idea how little code is neccessary using the Stepper.h library included with the Arduino software download:
#include <Stepper.h> //include the function library
#define STEPS 200 //1.8 deg motor (200 steps per revolution)
#define D0 13 // Arduino digital output numbers
#define D1 12
#define D2 11
#define D3 10
Stepper stepper(STEPS, D0, D1, D2, D3); //create the stepper

void setup() 
{
  stepper.setSpeed(30); //set speed to 30 rpm
  delay(1000); 
  stepper.step(200); //move 200 steps = 360 deg in one direction
  delay(1000); 
  stepper.step(-200); //move 200 steps = 360 deg in the opposite direction
}

void loop() 
{}

2009-06-04

ClipWrap 2 allows native AVCHD playback and editing on a Mac

ClipWrap 2.0 lets you quickly rewrap individual .MTS files into QuickTime .MOV files that can be played back in the QuickTime player or imported into Final Cut. But see yourself:

Note that Version 2 of ClipWrap is not available yet but it should come this summer (2009).

Hehe, I know this chicken in the YouTube clip above.

2009-05-10

H.264 encoding formula

Kush Amerasinghe, an engineer at Adobe has written an interesting primer on H.264 compression called "H.264 for the rest of us".
In this easy to understand paper he presents a very useful formula for estimating the video bitrate needed:

Bitrate [ kbps ] = Width * Height * fps * Motion * 0.07 / 1000

Width, height: Pixels
fps: Frames per second
Motion: Low = 1, Medium = 2, High = 4

Quote from the paper:

Low motion is a video that has minimal movement. For example, a person talking in front of a camera without moving much while the camera itself and the background is not moving at all.
Medium motion would be some degree of movement, but in a more predictable and orderly manner, which means some relatively slow camera and subject movements, but not many scene changes or cuts or sudden snap camera movements or zooms where the entire picture changes into something completely different instantaneously.
High motion would be something like the most challenging action movie trailer, where not only the movements are fast and unpredictable but the scenes also change very rapidly.

Example for a 25 fps video:
Low motion: 1280 x 720 x 25 * 1 * 0.07 / 1000 = app. 1500 kbps
Medium motion: 1280 x 720 x 25 * 2 * 0.07 / 1000 = app. 3000 kbps
High motion:1280 x 720 x 25 * 4 * 0.07 / 1000 = app. 6500 kbps

2009-04-08

Getting a grip on the HF100


Such a handle bar improves your handheld video shooting because it allows to have a firm grip on your HF100. It has wings like the SteadyWing the professional black of the Fig Rig and the balls from the SteadyGrip.

I wanted a good looking solution and found a 350 mm wide and 10 mm thick black anodized bow handle at norelem.de. I also ordered other parts from them. You can find the part numbers in the drawing above. Since the 40 mm balls have a M10 thread and the handle a M6 one I also ordered two 10 mm / 6 mm Helicoil thread adapters. Unfortunately the thread adapters didn't fit. I found out that a normal M10 thread is M10 x 1.5 while those Helicoil adapters are M10 x 1.25. My solution made on a lathe is shown below.

The Quick Change Adapter is mounted from above using a M6 bolt with countersunk head. This required cutting a M6 thread in the middle of the handle bar and countersinking the adapter. Alternatively the Quick Change Adapter can also be fastened through a 6.5 mm hole from below using a 1/4" screw.

For mounting the balls I drilled a piece of M10 threaded rod and cut a M6 thread into it. There are also ready-made M10 to M6 thread adapters available.

Another interesting solution "to get a grip" on tiny camcorders like the HF100 is the Foddis Pico.

2009-03-24

My new lens hood for the HF100

This lens hood is made by Mennon. It's available in black or silver and is mounted on a 37mm filter. It even comes with a cap. I ordered it from EnjoyYourCamera.com in Germany.

Mennon also produces a screw-in lens hood with 37mm thread that fits the camcorder directly without the need for a filter. But since an UV or IR blocking filter also protects the lens I strongly suggest to use one.

Note that such a wide lens hood blocks the iAF sensor, the LED light and the flash. Since I don't use any of these that's not a problem for me. I don't film fast moving objects and I don't want the camera to change focus too quickly therefore I'm fine with the slower contrast auto focus through the lens.

2009-03-21

Better sound with the Sennheiser MKE 400

I neglected audio for a long time. The built-in microphones are not bad but a good external microphone sounds better.

I've chosen the Sennheiser MKE 400 because of it's small size and good reviews. It records directional mono sound and is powered by a single AAA sized battery which allows about 300 hours operation time.

The MKE 400 recordings have much less noise and sound more transparent and natural but somewhat "thinner" with more treble and less bass. But listen for yourself:


Canon HF100 + Sennheiser MKE 400 from Martin Koch on Vimeo.

I used two HF100 for this comparison. Both camcorders where about 1.5 m (5 feet) away. Wind cut was off. Both HF100 where manually set to the same audio recording level (green indicator at the -12 dB mark)*. The MKE400 was set to "+" in order to have the same sensitivity as the built-in microphones. I recommend the "+" setting since the first amplication stage is the most critical and the preamp in the MKE 400 is most likely of higher quality (less noise) than that of the HF100.

Note that the MKE400 doesn't fit into the Mini Advanced Accessory Shoe of the HF100 without some sort of adaption. The simplest solution is to file the 18 mm wide plastic foot of the MKE 400 microphone to a width of 16 mm as shown in the photo above. By doing so you are able to slide the foot into the Mini Advanced Accessory Shoe plus you can still fasten the microphone securely on any standard flash shoe.

Ready-made adapters are available too. I found this Hague shoe adapter and this adapter at Adorama or DM-Accessories. By using such adapters you will also have extra distance between the microphone and the zoom lever of the HF100. Without there's a chance to touch the microphone while zooming which would produce unwanted noise.

Caution: If you make your own adapter use plastics material inside the mini accessory shoe since a short cut at the electrical contacts will damage the camera. Or stay clear of the electrical contacts like this adapter made of aluminum.

What's about the Canon DM-100 accessory microphone? It has no connection problems and it has two important advantages. First there's no audio cable since the electrical connections are made inside the Mini Advanced Accessory Shoe. It also doesn't need an extra battery since the power is supplied via the HF100. A big plus.

So despite all these advantages why didn't I order it? Because it's strange that you can't find a detailed description of this microphone on Canons website or in the HF100 manual. Very strange. I finally found an DM-100 review at amazon that reveals the technical data. E.g. 100 - 10,000 Hz in shot gun mode doesn't sound too convincing. The frequency response in stereo mode remains Canons secret. If Canon would be proud of their product they certainly would offer more information or even sound samples. Somehow it looks like another overpriced accessory. Unfortunately I had no possibility to actually try it out. You can see the DM-100 up close and personal in this clip:

Sennheiser on the other hand offers all specifications including a polar pattern diagram at the their website. The MKE 400 is also smaller than the DM-100 and it can be used on other cameras. I'm very pleased with it.

Of course the Sennheiser MKE 400 is a compromise between size and sound quality. There are better, fuller sounding microphones (Rhode make good ones) but all are much larger than the Sennheiser and will not fit as well to the HF100.

What's about stereo? It depends on what you're filming. You may want stereo in a wide angle shot of a large orchestra or of a car passing by in the distance but most of the time it will be a single sound source and narrow field of view so mono will be sufficient. The MKE400 is a directional microphone designed to isolate a single sound source so mono makes sense.

*To set equal audio levels on two cameras play a continuous, constant tone. I looped a 660 Hz sine wave recording using the QuickTime player.

2009-03-13

Wired control for the HF100

Professional camcorders often have an optional controller unit which allows to control the camcorder while having the hands on the video tripod. If you also want this luxury with your HF100 you might find a solution by the user "Modellbahner" at the Slashcam.de Forum interesting. Remote sensor and wireless control are simply connected by an audio fiber-optics (TOSLINK) cable.

The photos above are form the forum entry.

2009-02-25

.MTS file preview in OS X Finder

The $6.99 HD Quick Look plugin by shedworx.com allows a thumbnail preview of the first frame of .MTS AVCHD files in the OS X Finder.

They also offer VoltaicHD which allows conversion of standalone .MTS files to other QuickTime video formats without the need for the entire AVCHD file structure.

2009-02-23

HF100 Red Saw Tooth Fix for Final Cut Pro and Express

Copy and paste the green text below into a plain text editor

scriptid "Red Sawtooth Fix" //DO NOT LOCALIZE 
filter "Red Sawtooth Fix"; 
group "HF100 Fixes"; 

// Blurs the V channel in YUV a little bit

InformationFlag("YUVaware") 

code 

float colorSpace; 
colorSpace = kFormatYUV219;

BlurChannel(src1, dest, 0/renderres, 1, 0, 0, 0, aspectof(dest));  
BlurChannel(src1, dest, 0/renderres, 0, 1, 0, 0, aspectof(dest)); 
BlurChannel(src1, dest, 0/renderres, 0, 0, 1, 0, aspectof(dest)); 
BlurChannel(src1, dest, 1/renderres, 0, 0, 0, 1, aspectof(dest)); 

Save the text file as Red Sawtooth Fix.txt in
/Library/Application Support/Final Cut Support/Plugins if you use Final Cut Express or
/Library/Application Support/Final Cut Pro System Support/Plugins if you use Final Cut Pro

Restart Final Cut Pro or Express and look for the filter in the "HF100 Fixes" folder under the Video Filters menu

Apply the filter to any HF100 clip with red color in it and enjoy smoother reds.

HF100 Sawtooth Artefacts in PF25 mode.

I think I got it. There's no need to switch to interlaced recording for better image quality. I somehow understood Adam Wilts review (see previous post) as if the HF11 records better images in interlaced mode. But that was a misinterpretation. What Adam Wilt says is: if you compare progressive recordings of the HF11 to real progressive recordings of a professional camcorder the HF11/10/100 looks less good because of the sawtooth artefacts shown above. A real progressive recording camcorder will not show these artefacts. If he compares interlaced recordings of both camcorders the difference is very small though.

The 1:1 details shown above come from a slowly moving HF100. The progressive recording shows these red sawtooth artefacts because of the interlaced color coding. But the interlaced recording also shows these artefacts plus the typical interlace combs. So if you need progressive frames shoot in PF25 mode and live with the artefacts. I'm glad I don't have to deal with all this annoying deinterlacing stuff.

I don't understand how this interlaced 4:2:0 color coding stuff works but at least now I see the disadvantage of progressive frames recorded in an interlaced format .

Here's an Wikipedia article on chroma subsampling

2009-02-22

Detailed HF11 Review by a Pro

The HF11 has a bit rate of 24 mbits/s, otherwise it's identical to the HF10 and if you forget the internal storage its also identical to the HF100. I just found this review of the HF11 "NTSC" model by Adam Wilt. Its a very interesting read and it becomes quickly clear that this man is a professional who uncovers details I haven't found anywhere else.

One interesting thing is that Mr. Wilt prefers the interlaced recording quality over the progressive one because of the interlaced 4:2:0 color encoding. Take a look at the hummingbird’s head shot on page two of the review. I've seen those red sawthooths in my progressive recordings but couldn't explain why they are there. Now I know.

I think I'm going to take a second look at recording interlaced with my HF100. I knew it doesn't record real progressive frames but I was not aware of the interlaced color encoding.

Update: There's no need to record interlaced if you don't want to. See my next post.

2009-01-06

Canon HF S100 is the better choice


Canon HF S100

  • 1/2,6" sensor
  • 1920 x 1080 Full HD
  • 24 Mbps data rate
  • SDHC-card
  • 43,5 - 435mm lens
  • Fiter thread: 58mm
  • April 2009
  • 1300 EUR

Some "Pro" features like manual focus, custom button and wheel, zebra pattern or manual sound level control. Interesting although it would require a new wide angle adapter.

UPDATE: According to this German review the larger sensor area doesn't improve anything for video. Only photos benefit from the higher pixel count. Despite the larger sensor the low light performance didn't improve and the video resolution is in fact lower than that of the HF10/100! They measeured this three times!

2009-01-05

HF200 is going into the wrong direction

Canon will offer new HF20 and HF200 models in spring 2009. FullHD and 24 mbits/s but 17 per cent smaller with an even smaller 1/4" image sensor! Imagine this almost microscopic sensor size. Crazy!