This one keeps coming around again and again and it’s not well understood by many.

When the standards for HDSDI and connecting HD devices were originally set down, almost everyone was using interlace. The only real exception was people producing movies and films in 24p. As a result the early standards for HDSDI did not include a specification for 25 or 30 frame per second progressive video. However over time 25p and 30p became popular shooting formats, so a way was needed to send these progressive signals over HDSDI.

The solution was really rather simple, split the progressive frames into odd and even lines and send the odd numbered lines in what would be the upper field of an interlace stream and then send the even numbered lines in what would be the lower field. So in effect the progressive frame gets split into two fields, a bit like an interlaced video stream, but there is no time difference (temporal difference) between when the odd and even are were captured.

This system has the added benefit that even if the monitor at the end of the HDSDI chain is interlace only, it will still display the progressive material more or less correctly.

But here’s the catch. Because the progressive frame split into odd and even lines and stuffed into an interlace signal looks so much like an interlace signal, many devices attached to the PsF source cannot distinguish PsF for real interlace. So more often than not the recorder/monitor/edit system will report that what it is receiving is interlace, even if it is progressive PsF. In most cases this doesn’t cause any problems as what’s contained within the stream does not have any temporal difference between the odd and even lines. The only time it can cause problems is when you apply slow motion effects, scaling effects or standards conversion processes to the footage as fields/lines from adjacent frames may get interleaved in the wrong order. Cases of this kind of thing are however quite rare and unusual.

Some external recorders offer you the option to force them to mark any files recorded as PsF instead of interlace. If you are sure what you are sending to the recorder is progressive, then this is a good idea. However you do need to be careful because what will screw you up is marking real interlace footage as PsF by mistake. If you do this the interlaced frames will be treated as progressive.  If there is any motion in the frame then the two true interlace fields will contain objects in different positions, they will have temporal differences. Combine those two temporally different fields together into a progressive frame and you will see an artifact that looks like a comb has been run through the frame horizontally, it’s not pretty and it can be hard to fix.

So, if you are shooting progressive and yet your external recorder say’s it’s seeing interlace from your HDSDI, don’t panic. This is quite normal.

If you are importing footage that is indicated as being interlace, but you know it’s progressive PsF into most edit packages you can normally select the clips and “interpret footage” or similar to change the clip header files to progressive instead of interlace.

So, I’ve just spent 3 days demoing the F5 and F55 and the BVE show in london. It’s actually been a great learning experience for me as even though I have been lucky enough to have shot with the cameras several times already, at BVE I was asked to show all kinds of different modes and setups. Many of which I have not used myself. In doing so I came across a  few anomalies in the way the menus work, a few what Sony might call “features”. Anyway I thought I would start to list them here in case anyone else gets stuck, or perhaps more importantly as a reminder to myself of how how to get around the features. As I come across more I’ll add them here. The cameras are shipping with firmware that is in development. There are some bug fix firmware releases coming very soon (maybe even the next few days) and we can expect many small updates over the coming months as more feedback makes it’s way back to Sony. Over all everything works, but there are a few peculiar things that might trip you up. These notes are to the best of my knowledge correct at the time of writing, but may become out of date as new firmware is released.

Remember that if your shooting 4K 4096 x 2160 the aspect ratio is 17:9, so you might want to add a 16:9 framing marker from the viewfinder marker menu.

Understand the difference between the “System”, “Base Setting” modes. Make sure you read and understand page 32 of the manual. There are two key modes, Cine EI Mode and Custom mode. Cine EI mode locks the camera into Exposure Index, S-Log2 mode. You need to be in this mode if you want to shoot raw on the R5, in fact you can only select this mode if you have an R5 attached. You cannot change the ISO in this mode. When your in this mode your gain is indexed, that is, the camera always records at the base ISO (1250 on the F55 and 2000 on the F5). I assume that in later firmware you will be able to index the ISO, ie change the ISO of the LUT’s and metadata to fine tune your dynamic range.. The colour Gamut is S-Gamut. Only the colour temperature can be changed

In Custom Mode there are colour gamut two sub modes. The two modes are Normal and S-Gamut. S-Gamut offers a wider colour gamut than the normal colour gammut. In either mode the colour temperature and gain can be adjusted as can the gain/ISO. However in S-Gamut you can only choose between the 3 preset white balance settings of 3200, 4300 and 5500. If you want to dial in your own white balance or set a manual white balance (done in the camera menu) you have to be in “Normal” mode. A common reason for not being able to change the gamma curve (gamma options greyed out) is having the camera set to S-Gamut as this locks the camera to S-Log2.

In order to record raw with the R5 set “Shooting Mode” in “Base Setting” to “Cine EI,” and “Main Operation” in “Base Setting” to “RAW” of the System menu.

To output 4K using HDMI you must have the camera set to 4K 4096 x 2160. Then you have to go to the video output menu, output page and first turn off the 4K SDI output. Once you turn off the 4K SDI output you will then see the option to turn on the 4K HDMI output. You won’t see the 4K HDMI option until you have turned off the 4K SDI.

MLUT’s are only available when in Cine EI mode. In Custom mode, even if you select S-Log as your gamma curve, you won’t get any MLUT’s. You have to be in EI mode and have MLUT’s activated for the viewfinder or one of other outputs to get the MLUT options.  You only get the MLUT options in the menu when the camera is set to Cine EI.

Exposure Dissparity between XAVC S-Log2 material and raw. I need to try to get to the bottom of this one. Some of my raw material ends up looking hugely overexposed compared to the S-Log2. Anyone else seeing this? It all looks fine in the viewfinder when I’m shooting, but the raw looks over exposed while the S-Log2 is OK. So far it’s always graded back to sensible levels. 

 

So here it is, my own F5 and R5 all ready to go with from front to rear: Genus Elite matte box,  Samyang 35mm T1.5 lens (watch this space I have some exciting lens news coming soon). Genus Superior Follow Focus, MTF FZ to Canon adapter, Element Technica Micron bridge plate system and Micron top plate and handle. The viewfinder is the Sony L350 3.5″ LCD finder. Docked on the back is the R5 raw recorder and it’s all powered by a LiTH  150SI compact 150Wh battery. Still waiting on the AXS media 🙁 so no raw shooting just yet, the media should arrive later in the week.

I’m running a workshop at Advanced Media in Dubai this weekend (2/3 March 2013) as an introduction to the new Sony F5 and F55 cameras. The two day workshop will introduce the cameras, provide advice on the use of 4K and raw, look at various workflow options and provide plenty of hands on time with the cameras. Full details here.

I’ve used many different camera support systems over the years utilising both 19mm rods and 15mm rods. The newer, lighter cameras, especially the most recent Super35mm cameras really don’t need 19mm rods for most applications, so for these I’ve been using 15mm rods. I have a large container full of different camera brackets and support plates. Some are better than others. Most work OK and do what they are supposed to do, but even though they are all built around the 15mm diameter, 60mm spacing rod standard there is no real continuity of design or interchangeability amongst the camera support plates. You buy the bits for one camera and that’s the only camera it fits.

I’ve seen and used elements of the Element Technica Micron system before at various trade shows and events and I’ve always know it to be well made and well thought out. So when asked if I would like to try some of the components out on my own cameras I said yes. The Micron system is based around the same 15mm rods, 60mm apart standard of just about every other 15mm bracket or clamp on the market. The big difference though is that this really is a very well thought out integrated modular system. Parts from the bracket for one camera will normally work via a simple adapter, riser or shim plate on another. The same shoulder pad fits all the mounts and cleverly snaps on and off magnetically in most cases.

The key part is the Micron Bridge Plate. This is an adapter based on the Arri Bridge plate system but scaled down to a size more appropriate for todays lightweight cameras. The bridge plate attaches to the camera via an adapter plate or shim plate that ensures that the 15mm rods are at the correct height relative to the lens. This means that even when swapping from camera to camera your matte box or other 15mm rail accessories will all be at the same, correct height. It also means that if you have several different cameras (as I do) that you can use the same bridge plate on any of them. All you need is the correct shim or adapter plate for each camera.

When mounting on a tripod the bridge plate is slid on to a Micron dovetail rail, again this is a scaled down version of the original Arri dovetail. Using the dovetail allows you to quickly and easily balance the camera even if the centre of gravity of the system is a long way from the cameras centre. It also means that if you have several cameras fitted with the micron system swapping between them is simply a case of sliding them on and off the dovetail. When swapping lenses if you need to re-balance the camera you simply slide it along the dovetail. A small lever on the bridge plate turns about a quarter of a turn to lock everything very securely in place while a small spring loaded stopper prevents the camera from accidentally sliding off the dovetail.

The quality of the machining and the finish of the materials are excellent, this system exudes quality. The fit between parts is extremely precise and this means that there is very little flex or wobble. As a result even though the rods are only 15mm they are incredibly ridged and secure. This means that they will work well supporting all but the very heaviest of lenses. The rods supplied with the mounts are some kind of turned, very hard chrome alloy, incredibly stiff, but still remarkably light weight.

As well as the base plate parts the Micron system also includes a range of camera top plates, handles, lens supports, viewfinder brackets and adapters. The same handle fits all of the micron range and the view finder brackets etc. attach to the same handle. The handle, called the “Manhandle” is covered in mounting threads as well as one fore-aft and one side to side mounting for a 15mm rod. If you have a Sony F5/F55 then you can add a mounting spud that accepts the Sony viewfinder mount on the ManHandle.

If you have a Sony F3 you can even get a replacement side panel that removes the hand grip and zoom rocker and replaces it with an incredibly tough and sturdy side panel covered in mounting holes for accessories.

The F3 top plate allows you to remove the original F3 handle and rear viewfinder, replacing them with a sturdy cheese plate style top. Like this the F3 no longer feels like a cheap camera, it transforms it into a robust film making tool. Oh, if only Sony had done this with the F3 in the first place. Now I can mount my external recorder on the side of the camera securely and rigidly. If you choose you can use just the top plate and keep the standard Sony side plate with hand grip.

Even Sony’s new PMW-F5 and PMW-F55 cameras are already supported. There is a custom shim plate for the F5/F55 that puts the bridge plate at exactly the right hight and then adds mounting points for the shoulder pad. For the top of the camera there is a top plate that adds even more mounting points than already supplied by Sony as well as giving you the option to use either the standard Sony handle or a Micron Manhandle. A “spud” adapter then accepts the Sony viewfinder bracket.

I am very impressed by this system. The main reason is because it is a system, it’s not just a random collection of mounting plates and brackets but a decent modular system. The ease of balance with the dovetail, the amazing rigidity along with the beautiful quality makes the Micron system stand out from the crowd.

So, some of you may have already seen my short write up about my recent trial of the JVC HM650. Well I have now spent some more time with the camera and gone through the rushes in more depth. I have to say I am impressed.

Who’s it for? First of all lets consider where this camera sits in the wide world of cameras and who it is aimed at. It’s not designed to compete with the currently highly fashionable large sensor cameras. It’s not a camera aimed at high end productions. The JVC HM650 is aimed fair and square at journalists, news agencies and low budget documentary production. It’s priced to sell and sell it will as it does offer very good value for the money.

The HM650 really is a very clever camera, packed full of features that make it a great choice for news shooters. It has multiple codec and recording options, great for when you need to pool or share media. It has WiFi and 3G/4G connectivity via a USB host port where you can add wireless dongle. Brilliant for uploading material via ftp or (via a future firmware update) streaming your footage live. It has a 23x zoom lens, so it offers both a wide angle field of view for press conferences, color shots and GV’s as well as a long telephoto range for capturing those distant stories behind the police lines or security barriers.

3x 1/3″ 1920×1080 Sensors.

The HM650 has 3x 1920×1080 cmos sensors that perform very well. The images from the camera are nicely rounded. Remembering that this is a 1/3″ camera and considering it’s price point, the pictures are very nice. My test shoot on the Watercress Line, a preserved steam railway, took place on a beautifully sunny winters day. Days like this are challenging for any camera. Brilliantly bright blue sky but with deep, dark shadows thanks to the low sun. Throw in dark, sooty trains and any camera will have a tough time.

In addition when the sky is as blue as this in winter colours can look bleak and lack interest. The HM650 did a very capable job in these tough conditions. Colour reproduction was very accurate, maybe tending towards pink in the highlights a little bit, but never the less pleasing to view. Dynamic range is good for a 1/3″ camera. You don’t have the massive dynamic range that some of the new big sensor camera offer, but I didn’t feel that I was being excessively restricted in what I could shoot by a lack of dynamic range. At a guess I would estimate around 9 to 10 stops. Being a CMOS sensor the camera does have a small amount of skew and suffers from the usual rolling shutter issues. However, the engineers at JVC have realised that a camera like this is going to encounter a lot of flash photography. So they have added in camera flash band reduction which can be turned on and off in the menu. This is very effective, leaving only the very narrowest dark band across the image, but it doesn’t work in all modes or when you have the shutter switched on.

Perhaps more important than dynamic range alone is the way a camera handles over exposure. Some cameras do a terrible job with highlights suddenly going into nasty, ugly clipping with weird hues getting added to the over exposure. Non of that here. Over exposure is very well handled with a pleasant transition from non clipped to clipped. The camera is a little “videoish” but really not bad at all for a 1/3″ camera. I expect some of the “videoish” look can be dialed out through the comprehensive camera process page of the menu and next time I get a look at the camera I’ll take some time to go through this in more depth.

The one thing that did catch my eye was the lack of noise. In fact at times there was so little noise that the images looked a little plasticky. Clearly there is a lot of noise reduction going on in camera. The majority of modern cameras use noise reduction circuits to decrease the appearance of noise. These circuits, while reducing noise can introduce other image artefacts. One of the most common of these is image smear. On a static scene you won’t see this but move the camera or have something move through the shot and the motion can look slightly blurred. I did see a higher than average amount of this on the HM650. Don’t panic! JVC are aware of this. Not only are they aware of this, but they already have a fix (or at least useful improvement) in the pipelines. There will be a firmware update for the camera in the coming weeks that will fine tune the noise reduction to reduce the smear. This will almost certainly mean a little more noise in the pictures, but from what I’ve seen so far I think a little extra noise will actually improve the way the pictures look.

23x Zoom Lens

 

The 23x zoom lens is very nice to use. I’ve been using prime lenses a lot recently and it really was liberating to have a beautifully smooth zoom lens with such a long range. Slow creeping zooms are possible, although it is quite hard to get a completely seamless transition from a static shot to a zooming shot when using the zoom rocker, there always appears to the very slightest of jumps as you start or end a zoom.

This is no worse than most cameras in this class. Focussing manually uses the large focus ring. This is of the round and round, un-calibrated variety but it’s quite snappy and responsive. There is a separate ring for the zoom control as well as iris. It was nice to have a full size iris ring, even if it isn’t calibrated rather than a silly knob or dial. Just to the rear of the lens you have one push buttons for exposure and focus as well as switches to choose between auto focus and auto iris. These are well positioned and easy to use and I often took advantage of the iris button to quickly set my exposure which the camera did very accurately in most cases.

Viewfinders and Audio.

 

OK, so we have nice pictures, how do you see them. Well there is a nice 3.5″ LCD panel up on the handle as well as a small electronic EVF on the rear of the camera. The LCD is nice and clear and you can adjust the peaking (via the menu’s) to aid with focussing. The EVF is a small 0.45″ LCD panel with good resolution, but it’s small size means it’s hard to see critical focus. Many handycam camcorders suffer from this same issue. All the design effort goes into the LCD and the EVF’s often appear to be an afterthought. It’s not that the EVF is unusable, it’s just a bigger screen would be nicer.

Audio is as you would expect these days. A built in stereo mic plus a pair of XLR inputs with mic and line levels as well as phantom power. There are two small dials for setting the audio levels up on the handle of the camera. When the LCD screen is open you have access to all the audio controls and the dial. Close the LCD and just the lower part of the audio dials sticks out at the bottom of the handle, so you can still adjust the audio levels, but now there is some protection against accidental knocks and bumps. One extra bonus with the HM650 is an additional mini-jack input on the camera body for use with radio mics etc. This makes it easy to switch between say a handheld mic on the XLR’s and a radio mic without having to unplug anything, this is a nice touch.

SD Card Recording.

At the rear of the camera there are two slots for SD cards. The HM650 records in  a variety of codecs including Mpeg2, H264 and the AVCHD version of H264, so you have a choice of codecs. Bit rates go up to 35Mb/s. When using Mpeg2 you can choose between using either MXF. MP4 or.mov as the file wrapper. So Mac users will most likely use .mov and Avid users MXF. If your an XDCAM EX user then you might choose MP4. The 35Mb/s mpeg 2 codec is the same as the one used by Sony in the XDCAM EX cameras, so the workflow is well sorted and the footage support by all the major edit applications. Having the files wrapped in .mov’s (as opposed to the XDCAM EX MP4) removes the need to do any re-wrapping if you use Final Cut Pro and this is a real time saver. For the highest image quality you can use what JVC call UHQ (ultra high quality) mpeg4 avc h.264 which should offer better quality than the Mpeg2 or AVCHD modes, although I didn’t get a chance to really put this to the test. The HM650 can even record Mpeg2 to one of the SD cards while also recording AVCHD on the other card, all very clever stuff. Apparently the HM650 has an additional set of image processing circuits compared to the HM600. This extra processing power is what makes it possible to add the wifi and wireless features. As I said, in the future you’ll be able to stream live footage over an internet connection with the HM650. For now you can connect the camera to the internet using a wireless adapter and use ftp to transfer files from the camera to an ftp server. I didn’t have time to go through all of these advanced features, but if your doing TV news I can see this being a very handy camera to have.

With so many features the menu system is quite complex. It’s not hard to use, but there’s a lot of stuff in there so finding some things can take a bit of hunting. You can use a little thumbstick on the LCD panel or the playback controls on the cameras body to navigate through the menus. If you want to adjust the way the pictures look there is a comprehensive setup page where you can adjust the detail, matrix and gamma settings. There’s only one memory for these settings so no multiple picture profiles to choose from as with some other cameras, but the range of adjustment is good.

Conclusions:

Overall the HM650 is a good little camcorder. The build quality appears very good and the camera is well balanced and easy to hold. The pictures are good and comparable to most other 1/3″ pro camcorders. Where it really excels though is the feature set. A big zoom ratio, great codec and recording choices, flash band reduction, 15 second memory cache, the use of low cost SD cards and it’s streaming and internet connectivity. I’m quite sure that the HM650 will be very popular with journalists, reporters and news organisations as well as anyone else that need the ability to stream live or upload material quickly and easily. Nice one JVC.

I’m going to spend some more time with the HM650 to look at the paint and setup settings as well as the new firmware with improved noise reduction.

I’ve been loaned a JVC HM650 to take a look at. I used it at the weekend to shoot some steam trains on a local heritage railway line. This is always a challenging subject and the bright sunny skies on Sunday made it very tough. Black, smokey trains agains a brilliant bright sky is tough on any camera. Reviewing the rushes today I have to say that the camera does produce a nice picture. It’s not a PMW-200 or F5, but then it isn’t the price of either of those, it’s considerably cheaper. Having spent two weeks shooting with prime lenses on an F5 it was really nice to get back to a video zoom lens. The 23x zoom range of the HM650 gives great flexibility and would be a real boon to anyone shooting sports or event videos. I’ll be posting a much more detail review in due course but so far I am impressed. The build quality is really first class (something JVC have always done well) and the camera feels good and solid. It’s quite large for a 3x 1/3″ camera, but that makes it easy to handle and operate. Image noise, sensitivity and dynamic range are what you would expect for a pro level camcorder with 3rd inch HD sensors. JVC have perhaps been a little too aggressive with the noise reduction algorithms and this does result in a little bit of smear in the images but I have been told that there will be a series of firmware updates for the camera to address small issues such as this. Personally I’d rather see a little more noise in the pictures and have less smear. The problem is that the otherwise very clean and noise free pictures really show up the smear when you pan or move the camera. A slightly nosier picture would to some extent hide any smear. Most modern cameras use noise reduction to help clean up the images, so many cameras suffer from smear, it’s not unusual these days. Out of the box the pictures are also in my opinion a little over sharpened and this also tends to draw your attention the smear as the picture softens as you move the camera. This is not a big deal though as the HM650 has a good range of controls for adjusting the image quality including detail correction, gamma and matrix settings. A few small tweaks to these really helps improve the image quality. If your brave you can even dial in your own custom looks for different shooting applications.
The HM650 uses the same codec as the Sony 35Mb/s XDCAM cameras, only JVC allow you to choose whether to have the video wrapped in a straight forward quicktime .mov file or in a MXF file. The footage is recorded on to SD cards (two slots) which really helps keep life very simple as most modern laptops have SD card slots and SD card readers are two a penny. The HM650 is very similar to the HM600, picture quality is the same for both cameras but the 650 adds some clever tricks and extra wiFi connectivity for streaming etc. More about that in my full write up.
Based on my brief time so far with the HM650 it is a very serious contender in the low to middle end of the pro camcorder market. It’s very easy to pick up flaws in the images of a camera, especially when you’ve been spoilt by the images from a high end large sensor camera like the F5. But I have to put things into perspective. The HM600 and HM650 are cheaper cameras for different applications. I’d be happy to use one as a B camera to a broadcast shoulder mount camera or as a run and gun companion to a large sensor camera. The pictures are overall very pleasing and when you factor in the flexibility of that massive 23x zoom range the HM650 does appear to punch above it’s weight. A more in depth review and write up will follow soon.

Well here is a little teaser from my trip to Norway to shoot the Aurora. Over 24,000 still frames were shot with the Sony Alpha A99 and NEX5. Over 4 hours of video rushes shot on the PMW-F5, Action Cam and A99. All in all an extremely successful trip and some really great material to use in my short film that will be released a little later in the year. Quite a few people have been asking about how the cameras performed, I will write it all up as soon as I get time. The F5 really surprised me. Some of the footage has really blown me away.

Not so much the sensitivity (I think the F3 is slightly more sensitive) but the really incredible dynamic range. Take a look at the fire frame grab. You can almost feel the heat from the fire! The richness of the image speaks for itself and this is ungraded. For interviews against the brilliant white snow the dynamic range really helped. I was really lucky to come across some traditional reindeer herders up on the arctic plateaux.

It was one of those un planned situations with the very real risk that the herders would have to dash off at any moment, so no setup, just grab the interview asap. The cameras broad dynamic range was a real help and the interview looks perfectly OK, even though I’d rather have used a reflector for a little fill and sparkle in the guys eye’s.

Anyway here’s the video clip, mainly time-lapse from the Sony Alpha A99:

 

I’ve been a little quite the last couple of weeks because I’ve be preping and now shooting the Aurora up in Norway. Last night we had an incredible show, bright Aurora’s all night. The only problem was the temperature….. -30c, -22f. I did experience a couple of small issues with the cameras throwing up errors once they fully cooled down (they were outside for 8 hours), but despite the very harsh conditions all the cameras produced some incredible images. I got real-time footage of the Aurora with the PMW-F5 without having to resort to the slow shutter.

I got stunning timelapse sequences with the NEX5N and Sony A99. As I write this the temperature is -32c and forecast to get even colder tonight. The cameras are all outside snapping and time lapsing away as the sun comes up and turns the snow and ice brilliant orange. I can’t wait to share the video clips and images, but that will take a while as so far I have shot over 8,000  still frames and a couple of hours of video.

I’m not sure I fully understand the obsession with using the shutter set in degrees on video cameras. For years video cameras have used fractions of a second to display the actual shutter speed. Very simple, tells you exactly how long the shutter is open no matter what your shooting frame rate. Basic film cameras use a fixed rotating shutter. This is a disc that will have half of it cut away to allow light to fall on the film. If a full circle is 360 degrees then half of this is 180 degrees, hence the commonly used 180 degree shutter. As these basic shutters are fixed then if you changed the film cameras frame rate then the shutter speed changes too. The shutter speed will always be half of the frame rate. More advanced film cameras have shutters where you can adjust the amount angle of the shutter opening, sometimes to as much as 270 degrees, but often only to an angle less than 180 degrees.

When you use degree’s your having to continually make a mental calculation of your shutter speed in fractions of a second to ensure that you don’t run into phase issues with your lighting etc. Why do this? With a video camera, if you use fractions of a second you know exactly where you are. I know of many film cameramen, myself included that found degrees to be a nuisance with the shutter speed changing all over the place depending on frame rate and angle. Fractions of a second are far easier to work with. For example, to avoid flicker from artificial lights (in particular florescent office lighting) when shooting in 50hz areas use a shutter speed that is a multiple of 1/50 and in 60hz countries use a fraction of 1/60, no matter what your frame rate. Try figuring out what angle you need to shoot 24p in a 50hz country (the answer is 1/172.8). Degrees is a hangover from film days that is seen as fashionable because it make you sound like a cinematographer, but this is fashion for the sake of fashion, not because it makes sense or is a better way to work. There is no difference in the way the shutter functions within an electronic video camera whether you use degrees or fractions, it’s just a different way of describing the same thing (unless you have a high end camera like the f65 with a mechanical shutter). If you want to mimic a film camera with a 180 degree shutter then all you have to do is halve the frame rate, so 24p = 1/48, 25p = 1/50, 30p = 1/60. Very simple.  Then if you need to match the local mains frequency simply use the next highest mains multiple. So if shooting 24p in a 50hz country use 1/50th or shooting 24p in a 60hz country use 1/60th, much easier to figure out than degrees.