All posts by alisterchapman

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Two PMW-F3’s used on 3D Cinema Commercial.

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Alister Managing the F3's on a Hurricane Rig.

I got back late last night from a big budget cinema commercial shoot where I was working with a pair of F3’s on a Hurricane Rig. All went very well and the DoP, (Denzil Armour-Brown)  was impressed by the F3’s. The overall light weight of the complete system really helped us when moving from position to position. We used a ton of Chapman grip equipment including sliders and dolly’s. I was responsible for the 3D rig, camera setup and alignment as well as assisting the DoP.
We shot using 2 sets of band new Zeiss Ultra’s, mainly at 32mm and 50mm (very nice) as well as some older and very heavy Arri 100mm macro primes. Our only small issue was that the follow focus motors were shifting the camera very slightly due to flex in the tripod base plate on the F3. You probably wouldn’t notice this at most normal focal lengths in 2D but in 3D small shifts are very obvious. So a stiffener plate for the base will be needed to prevent this (as well as general flex) or a pair of 15mm rails mounted to the top holes on the F3 body.

We were recording to a Nano3D (2 x Nano Flashes) as well as to a Mac workstation recording ProRes in the video village. The video village allowed for instant playback on 50″ 3D monitors in a blacked out tent for review and tech assessment.

It was an outdoor shoot in great weather. As well as the F3’s there was a second rig with a pair of Phanton HD Gold 35mm high speed cameras shooting 3D at 1000fps. So even thought the sun was shining brightly, many shots were done with 2 or 3 18kw lamps!!

Towards the end of day the F3 rig was tasked with shooting some blue screen and other effects shots and in effect I became 2nd unit DoP. The effects shots will be matted in to the finished commercial.
I’m under NDA so can’t talk about the subject just yet, or post any pictures that show the subject, but once the ad is released (2 weeks time!!) I’ll be able to post some grabs and more photos.

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Two PMW-F3’s used on 3D Cinema Commercial.

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Alister Managing the F3's on a Hurricane Rig.

I got back late last night from a big budget cinema commercial shoot where I was working with a pair of F3’s on a Hurricane Rig. All went very well and the DoP, (Denzil Armour-Brown)  was impressed by the F3’s. The overall light weight of the complete system really helped us when moving from position to position. We used a ton of Chapman grip equipment including sliders and dolly’s. I was responsible for the 3D rig, camera setup and alignment as well as assisting the DoP.
We shot using 2 sets of band new Zeiss Ultra’s, mainly at 32mm and 50mm (very nice) as well as some older and very heavy Arri 100mm macro primes. Our only small issue was that the follow focus motors were shifting the camera very slightly due to flex in the tripod base plate on the F3. You probably wouldn’t notice this at most normal focal lengths in 2D but in 3D small shifts are very obvious. So a stiffener plate for the base will be needed to prevent this (as well as general flex) or a pair of 15mm rails mounted to the top holes on the F3 body.

We were recording to a Nano3D (2 x Nano Flashes) as well as to a Mac workstation recording ProRes in the video village. The video village allowed for instant playback on 50″ 3D monitors in a blacked out tent for review and tech assessment.

It was an outdoor shoot in great weather. As well as the F3’s there was a second rig with a pair of Phanton HD Gold 35mm high speed cameras shooting 3D at 1000fps. So even thought the sun was shining brightly, many shots were done with 2 or 3 18kw lamps!!

Towards the end of day the F3 rig was tasked with shooting some blue screen and other effects shots and in effect I became 2nd unit DoP. The effects shots will be matted in to the finished commercial.
I’m under NDA so can’t talk about the subject just yet, or post any pictures that show the subject, but once the ad is released (2 weeks time!!) I’ll be able to post some grabs and more photos.

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Alan Roberts F3 assessment. Confusing Reading.

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Alan Roberts F3 assesment is now online: http://thebrownings.name/WHP034/pdf/WHP034-ADD68_Sony_PMW-F3.pdf

In the report Alan observes the aliasing that I have seen from the camera, in particular the high frequency moire, so no surprise there. But he also measures the noise at -48.5db. Now I don’t have the ability to measure noise as Alan does and I normally respect his results, but this noise figure does not make sense, nor does his comment that the camera has similar sensitivity to most 3 chip cameras. To my eyes, the F3 is more sensitive than any 3 chip camera I’ve used and it’s a lot less noisy. The implication of the test is that the F3 is noisier than the PMW-350. Well that’s not what my eyes tell me. Take a look at the noise graph Alan has prepared. The hump in the noise figure curves at 0db also appears to be dismissed as insignificant, yet it means a greater than 4db difference between what the curve implies the noise figure should be and the measured noise figure. It really doesn’t seem to fit and is very strange. Video amplifiers and processing are normally pretty linear with gain giving a consistent increase/decrease in noise that follows the gain curve. If you read off the noise figures from the graph, the F3 appears to have less noise at +6db gain (-49.5db)  than at 0db (-48.5db). So id we are to believe Alan’s test then we should be using +6db gain or -3db gain (-53.5db) but not 0db, sorry but that just does not add up and to dismiss the 0db noise bump as “not significant” is something I don’t really understand as too me it is significant. Either there is something very strange going on with the F3 at 0db, or there is something up with the test. I suspect the later, perhaps the individual camera had some odd settings, as my F3 is quieter (visually) at 0db than +6db. I would need to check it out on a scope back at home to verify this.

There are also assumptions made about the pixel size and sensor pixel count that are quite wrong. Alan suggests the sensor to be a 12 Mega Pixel sensor, this suggestion is based on Alan’s opinion that the F3 has similar sensitivity to a 2/3″ 3 chip camera, so therefore the pixel size must be similar and the bigger sensor means that it must have 12 MP, yet Sony have published that it is 3.3 mega Pixels (same sensor as FS100). 3.3MP equates to roughly 2422 x 1362 pixels, for a bayer sensor this is a little under the optimum for 1920 x1080 (IMHO) and may explain the aliasing as Sony are probably trying to squeeze every last bit of resolution out of the sensor.

Alans assessment of his zone plate results also concludes that the R, G and B resolutions are the same and that the sensor resolution must be much higher than 2200 x 1240. Well I would not call 2422 x 1362 “much” higher and if this is a bayer sensor (neither admitted or denied by Sony) then the G resolution should be higher than the R and B. So could this be a case of conventional conclusions about an unconventional sensor, or have Sony managed to completely wrong foot Mr Roberts?

An interesting finding was that detail at zero, frequency at +99 and aperture at +20 gives the least aliasing. This is quite different from my own findings and will need further exploration.

The F3 assessment is also missing the usual customary round up from Alan where he suggests whether the camera is suitable for HD broadcast or not. I’m really glad I got my F3 before reading the report as I have seen with my own eyes the beautiful clean images the F3 produces. I strongly recommend anyone considering the F3, but put off buy this report to take a look at the pictures for themselves before making any decisions.

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Alan Roberts F3 assessment. Confusing Reading.

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Alan Roberts F3 assesment is now online: http://thebrownings.name/WHP034/pdf/WHP034-ADD68_Sony_PMW-F3.pdf

In the report Alan observes the aliasing that I have seen from the camera, in particular the high frequency moire, so no surprise there. But he also measures the noise at -48.5db. Now I don’t have the ability to measure noise as Alan does and I normally respect his results, but this noise figure does not make sense, nor does his comment that the camera has similar sensitivity to most 3 chip cameras. To my eyes, the F3 is more sensitive than any 3 chip camera I’ve used and it’s a lot less noisy. The implication of the test is that the F3 is noisier than the PMW-350. Well that’s not what my eyes tell me. Take a look at the noise graph Alan has prepared. The hump in the noise figure curves at 0db also appears to be dismissed as insignificant, yet it means a greater than 4db difference between what the curve implies the noise figure should be and the measured noise figure. It really doesn’t seem to fit and is very strange. Video amplifiers and processing are normally pretty linear with gain giving a consistent increase/decrease in noise that follows the gain curve. If you read off the noise figures from the graph, the F3 appears to have less noise at +6db gain (-49.5db)  than at 0db (-48.5db). So id we are to believe Alan’s test then we should be using +6db gain or -3db gain (-53.5db) but not 0db, sorry but that just does not add up and to dismiss the 0db noise bump as “not significant” is something I don’t really understand as too me it is significant. Either there is something very strange going on with the F3 at 0db, or there is something up with the test. I suspect the later, perhaps the individual camera had some odd settings, as my F3 is quieter (visually) at 0db than +6db. I would need to check it out on a scope back at home to verify this.

There are also assumptions made about the pixel size and sensor pixel count that are quite wrong. Alan suggests the sensor to be a 12 Mega Pixel sensor, this suggestion is based on Alan’s opinion that the F3 has similar sensitivity to a 2/3″ 3 chip camera, so therefore the pixel size must be similar and the bigger sensor means that it must have 12 MP, yet Sony have published that it is 3.3 mega Pixels (same sensor as FS100). 3.3MP equates to roughly 2422 x 1362 pixels, for a bayer sensor this is a little under the optimum for 1920 x1080 (IMHO) and may explain the aliasing as Sony are probably trying to squeeze every last bit of resolution out of the sensor.

Alans assessment of his zone plate results also concludes that the R, G and B resolutions are the same and that the sensor resolution must be much higher than 2200 x 1240. Well I would not call 2422 x 1362 “much” higher and if this is a bayer sensor (neither admitted or denied by Sony) then the G resolution should be higher than the R and B. So could this be a case of conventional conclusions about an unconventional sensor, or have Sony managed to completely wrong foot Mr Roberts?

An interesting finding was that detail at zero, frequency at +99 and aperture at +20 gives the least aliasing. This is quite different from my own findings and will need further exploration.

The F3 assessment is also missing the usual customary round up from Alan where he suggests whether the camera is suitable for HD broadcast or not. I’m really glad I got my F3 before reading the report as I have seen with my own eyes the beautiful clean images the F3 produces. I strongly recommend anyone considering the F3, but put off buy this report to take a look at the pictures for themselves before making any decisions.

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Getting good SD from an HD camera.

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This a recurring question that I get asked about time and time again. The main problem being that the SD pictures, shot with an HD camera look soft. So why is this and what can be done about it?

Well there are several issues to look at. First there is camera optimisation. Sadly what works for HD doesn’t always work well for SD. Secondly there is the downconversion process. If your shooting HD and simply outputting SD using the cameras built in downconverter than you really don’t have many options but if your using a software downconverter you may be able to improve the results your getting.

Starting with the camera, what can you do? Well first off let me say that a camera optimised for HD will always be a compromise when it comes to SD. As the native resolution of HD cameras increases then the problem of getting good looking SD actually gets worse. The problem is that a good high resolution camera will normally only have a very small amount of artificial sharpening via the detail or aperture circuits, because in HD it will look nice and sharp anyway. SD cameras and the SD TV system with it’s inherently low resolution and soft pictures has always relied very heavily on detail enhancement to try and make the pictures appear sharper than they really are. When you take the minimal additional sharpening of an HD camera and downconvert it to SD it all but disappears, the end result is a soft looking picture. There is no easy fix for this, you can either add additional extra thick detail correction edges to the HD pictures, which risks spoiling the HD image or you can add additional detail correction in post production. On a Sony camera the thickness of the detail correction edges is controlled using the “frequency” setting. Setting this to a negative number will thicken up the detail edges, very often you need to go all the way to -99 to get an appreciable difference. As an alternative you can add extra sharpening or detail correction in post, after the downconversion process. This is the way I would go whenever possible as I don’t want to compromise my HD pictures for the sake of the SD images.

The second issue is the quality of the downconversion. A simple rescale from HD to SD rarely works well as it can create a lot of aliasing. Aliasing is the result of taking too much detail and trying to record or represent it with too few pixels. See this article for more on aliasing. Imagine a diagonal line running through your image.

Diagonal Line Sampled in HD
Diagonal Line Sampled in HD

If you sample it at a high resolution, with your HD camera then the line looks reasonably good as you can see in the diagram to the left.

Simple SD Downconversion
Simple SD Downconversion

If you then take that HD captured edge and simply scale it down to SD, you quarter the number of samples and the end result is a jagged, stepped line. Not pretty. In addition, if the line moves through the image it will flicker and “buzz”. This is far from ideal.

Same Line, Blurred Before conversion to SD
Same Line, Blurred Before conversion to SD

A better approach is to blur the HD image before down converting using a 4 pixel (or similar) blur, or to use a downconversion programme that will include smoothing during the conversion. The final image shows the kind of improvement that can be gained by softening the image before down conversion. The blur around the edges of the line soften it and make it appear less jagged. This will result in a much more pleasing SD image.  Next you then add in some detail correction to restore the apparent sharpness of the image and viola! A decent looking SD image from an HD source. In compressor to get a good downconversion you need to activate the advanced scale tools and use the “better” or “best” scaling options.

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Ultimate Documentary Production workshop. (3D as well if enough interest)

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Alister Shooting a Supercell Thunderstorm

I’m planning on running a Documentary production workshop and 3D workshop based on a Storm Chasing trip to the USA from the 4th to the 12th of June. The trip would be an excellent chance to really put your documentary skills in to practice and learn more about your cameras and workflow shooting a short film about the violent weather that hits Tornado Alley every spring. We can even shoot in 3D if that’s what people are interested in. I can provide a PMW-F3, lens kit and EX1R, but hopefully you would bring your own cameras and I can teach you how to get the most out of them. depending on the weather each day there would be a classroom session or practical on location session covering everything from sound and interview techniques, to camera setup and shooting tips. Will will do a lot of timelapse, make use of cache record (if you have it) and work in some very challenging lighting situations. Each member of the group will be given different roles to play as part of the “crew” each day so that they may gain a better understanding of the difficulties of each role. At the same time the idea is that each person will also create their own personal short film about our storm chasing adventure. With luck we should see incredible thunderstorms, giant hail and maybe even a tornado or two (I’ve been storm chasing for 12 years, it’s my speciality). The cost for this comprehensive and very exciting workshop will be $1800 USD per person for a place on the course. In addition to that each student will be responsible for their overnight accommodation. Typically we will stay in hotels/motels that cost approx $100 USD per night, so you should budget for approx $800 for accommodation bringing the total to $2600. We will depart from Denver, Colorado so you will have make your own travel arrangements to/from Denver. This will be a real educational adventure. The previous trips I have run to Norway for the Northern lights, Arizona for lightning and Tornado Chasing have been great successes with many people returning for more. We will spend a lot of time on the road, visiting many parts of the Mid-West. It will be fun and you should come away with improved video skills, a great short film, and amazing stories of adventure and excitement. Please use the contact form if your interested. Places are limited.

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Look how small the Gemini is!

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Gemini 4:4:4 recorder on Panasonic AF100

Just obtained a picture of a pre-production Convergent Design Gemini mounted on a Panasonic AF101. It really shows just how compact this device is. The LCD is 800×400 resolution and a very bright 800 nits, which is nearly twice as bright as an iphone or ipad! You have to remember that this is not just a monitor but also a 4:4:4 10 bit, uncompressed recorder! With a street price of less than $6k this will be the perfect match for the Sony PMW-F3.

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Lens Tests at F3 Dubai Workshop.

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Off to the airport to fly home in a minute, but I thought I would jot down some notes about the various lenses we were able to look at during the F3 workshop I ran here in Dubai. We had a set of the Sony PL primes, a Zeiss CP2, some Zeiss ZF.2 stills lenses, a Nikon 50mm and a Tokina 28-70mm ATX pro zoom. The stills lenses were all attached to the F3 using an MTF to Nikon adapter.

It was hard to see any difference between the Sony primes and the CP2, this was kind of expected. When comapring the PL’s to the Tokina zoom, the zoom was a little soft wide open at f2.6. Stopped down half a stop and it looked much better, but it needed to go down to f4 before it came close to matching the PL’s. Even then the PL’s had the edge, but then this is comparing a zoom to a prime. I would certainly have no hesitation over using the Tokina at f4 or more closed. The Nikon 50mm pancake, f1.8 was surprisingly good. Even wide open it produced a respectable image, stopped down to f2.8 it was a very close match to the PL’s. The Zeiss ZF.2’s were the budget stars of the show as even wide open these produced sharp, clean images with very similar bokeh and flare performance to the primes, very impressive performance.

Of course ergonomically the PL’s were better. Bigger focus rings, bigger iris rings and better focus scales. The CP2 impressed with it’s near 360 degrees rotation of the focus ring with very clear and accurate witness marks and wide distance spacing even approaching infinity. If I could afford a set of CP2’s that’s what I would buy, but I can’t. The Sony PL’s are good lenses, they don’t quite have the build quality of the CP2’s but they do represent excellent value for the money. If your budget won’t stretch to PL glass then the Zeiss ZF.2’s are about as close as you’ll get to a PL lens, but do watch out for the amount of telescoping when you focus the longer focal length ones. That can make using a matte box very tricky. I know my Nikon 50mm and Tokina 28mm primes work well. The Tokina 28-70 while not as sharp as the primes will still make a good all-round lens. All I need now is to get a nice 85mm and 135mm and I’ll be happy. Maybe a couple of ZF’s.