Category Archives: cameras

Exposing when shooting S-Log.

The question over whether to deliberately underexpose or not with S-Log came up recently. I believe that you need to evaluate the entire scene when shooting S-Log and that the often heard “underexpose by a stop” methodology may have some issues. Here’s my take on the situation:

A couple of caveat’s first: Most of my F3 S-Log work has been in indoor situations as I have been tied to recording to various less than portable 10 bit recording solutions, so very often using a restricted contrast range. I’ve only owned S-Log for my F3’s for a short while now, so many of my earlier tests were on 3rd party cameras, some of these were beta cameras.

I have not fully tied down my workflow. I’m still investigating external recorders, everything from the Ninja, Ki-Pro, Sound Devices and of course Gemini. I’m leaning very heavily towards the Gemini as I do a lot of 3D and the Gemini LCD makes for a fantastic monitor.
Back to exposure, this is obviously going to be a slightly contentious area as there is no real “correct way to do it”. While I might not agree with pinning skin tones or anything else for that matter to one particular brightness range, that does not mean I’m right and anyone else is wrong, it is just a different approach and methodology. At the end of the day, if it works for you and gets the results you want, then that will be the way you should go, these things are not black and white, right or wrong.
A very un-scientific test that a did a while back was an eye opener for me. I was exploring the finite latitude of S-Log compared to the F3’s cinegammas. I did a couple of very quick shots, you will find them here: http://www.xdcam-user.com/2011/06/pmw-f3-s-log-and-cinegamma-quick-look/
When I filmed these two examples I was looking at dynamic range, I exposed in both cases with the bright whites of the back wall behind the girl just going into clipping so I could then see how far into the shadows I could still see useable detail. I was not concerned about getting the skin tone exposure correct. When you look at the raw S-Log it really looks pretty shocking and even I wasn’t sure how much I would recover from the highlights and the girl is a good stop overexposed. However after a very simple grade using only the colour corrector in FCP, I was able to extract a pretty good looking image and it’s amazing how much detail was actually retained in what looked like over exposed high lights.  The Girl’s skin tones which I’ve measured at over 85IRE came down very nicely without any issue. A proper grade in a grading suite would I’m sure improve them still further.
What this very crude test told me was that you have incredible flexibility over where you put skin tones, you can comfortably move them up and down in post by a quite significant margin. Also seemingly overexposed S-Log highlights will contain surprisingly large amounts of fully recoverable detail. In the same test I graded the Cinegamma material to try to recover the shadow detail that was lost by due to the reduced latitude. This involved attempting to pull up the shadow areas. While this was somewhat successful, what became very apparent was the way the noise increased quite dramatically, this is something I have been aware of since I started using Cinegammas many years ago, pulling levels up will increase noise.
So… when I expose with Cinegammas (as I have done for many years) I have always been very conscious of the noticeable effect on noise that trying to lift underexposed parts of the image has. Very often in the grade the limiting factor as to how far you can push the image has been down to the noise floor and noise effects. This has mainly been with Sony EX’s which have a 54db noise floor.
Now with the F3 with have a dilemma! S-Log gives us another +1.5ish stops of dynamic range, but at the expense of a +6db increase in noise due to the +1 stop increase in sensitivity associated with S-Log.
Lets say for example that we shoot a shot with a person and we under expose the face by one stop (one stop = 6db).
If we do this with with the Cinegammas and then grade the shot bringing the face up one stop then the noise will increase by 6db from the base noise figure of 63db giving a final noise figure of approx 57db (in the case of signal to noise, a lower number is worse).
If we do this with S-Log and then grade the shot bringing up the face by one stop then the noise will increase by 6db from the base of 57db giving a final noise figure of approx 51db.
So the S-Log image becomes twice as noisy as the cinegamma material and therefore depending on the footage, it is quite possible that you would actually be able to push mid ranges and shadows further with Cinegammas than S-log in an underexposed situation due to noise issues. The S-Log and Cinegamma curves are almost identical up to over 50IRE, so latitude performance under 50IRE is essentially the same. See the charts on this page: http://www.xdcam-user.com/2011/05/s-log-a-further-in-depth-look/
If I get some time at IBC I might see if I can set up some tests to show this in practice.
Now given that I have seen for myself how with S-Log skin tones can be pushed down just as much as up in post, I tend to try to evaluate the entire scene and consider how it will be treated in post before choosing how to expose. In particular I don’t want to expose so that the entire scene will end up being lifted by a significant amount, as noise will become a concern. This isn’t always going to be possible as there are many shots where highlights have to be protected, but I don’t believe that you have to set skins etc at any particular narrow brightness range, I tend to let skin ride somewhere between 45IRE and 70IRE depending on the overall scene.
If I can fit the contrast range of the scene into the 11.5 stops of a cinegamma then I will often use the cinegammas over S-Log because of the noise improvement. S-Log comes into it’s own where you have an extreme contrast range that needs to be captured. However at the end of the day you do still have to remember that the end display device is unlikely to be able to display more than 7 stops with any accuracy!
One tool I have found very useful is the BlackMagic HDLink box. I often use this to connect to a monitor as it has the ability to apply LUT’s very quickly. If you have a PC connected to the HDLink you can go in an modify the LUT curve in real time and in effect do an on-set grade. The HDLink is only $499 USD.

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Camrade CB Single III Camera Bag.

I was asked by my good friend Rene of Camrade to take a look at some of their new products. So over the next couple of weeks I’ll be looking at the CB Single III camera bag, the PMW F3 rain cover and a new PL lens adapter for the Sony FS100. First I’m going to take a look at the camera bag.

bag1-300x224 Camrade CB Single III Camera Bag.
Camrade CB Single III

I’ve had Camrade bags before and they have always lasted well, standing up to the knocks and bumps that go along with lugging kit all over the place. I was in the market for a new bag for one of my PMW-F3’s, so I was sent the CB Single III bag. From the outside this is a functional looking bag with a large mesh pocket on one side and further external pockets on the other side and at one end. It has a nice well padded chunky carry strap that is comfortable to use.

bag2-300x224 Camrade CB Single III Camera Bag.
Inside the Camrade CB Single III

The top of the bag opens up with a dual zipper system that gives you completely un hindered access to the bags interior. This is great for run and gun where you may need to quickly grab the camera from the bag and you don’t want to have to squeeze it out through a small opening. The interior of the bag has various dividers that are secured by velcro, so you can customise the layout to suit your needs. One of the dividers forms a clever storage box to one side of the bag. I’ve found this particularly useful with the F3 as I can safely store my Genus 4×4 Matte Box and a couple of DSLR lenses in here.

bag3-e1312127885429-300x224 Camrade CB Single III Camera Bag.
Opening the storage compartment shows moveable dividers

Then my batteries, other bits and bobs and the rain cover fit comfortably in the end compartments. This bag really works well with the F3 alloying you to get a complete basic shooting kit into one bag without the bag being too big or bulky.

It’s not perhaps the most fancy or sophisticated of bags, but in terms of practicality and functionality it works very well indeed. There is a strap in the main compartment to hold the camera secure if your really going to be bouncing it around. The base and sides of the bag are all semi ridged and have a good layer of shock absorbing foam in them. With one of these bags typically costing a very affordable $200 it really does represent good value for money.

My thanks to Rene for the sample bag. http://www.camrade.com/products-page/video/cambags/cb-single-iii1

In my next post I’ll look at the nice rain cover that Camrade make for the F3.

PMW-F3, Run “n” Gun, is it worth the effort?

For me early Summer means airshow season and there are a couple of events that I shoot every year. The first is Flying Legends at the Imperial War Museum site at Duxford and features vintage aircraft predominantly from the second world war. The following weekend is the Royal International Air Tattoo, one of the largest military air shows and is all about the latest fast jets and military hardware. For the last 3 years I have been tasked with shooting aircraft being prepared for flight at both shows and for this I have been using a variety of cameras, but almost always some kind of ENG type camera. I’ve used PDW700’s, EX1’s and EX3’s. This year however it was decided to try and use one of my PMW-F3’s in order to take advantage of the shallow Depth of Field and give the footage a higher quality, filmic look.

Of course using the F3 for a shoot like this brings many challenges and one of the reasons for using it on these projects was to discover exactly whether the trade off between ease of use and shallow DoF was worth it. Thankfully, producer Steve Connor (flying machinestv.co.uk) is willing to let me try new things on his productions.

So how was it? Well it was hard work compared to running around with an EX1 or EX3. You have to check, check and double check focus all the time and this slows you down a little. The other thing is the lens. A camera like the EX1 has a 14x zoom lens giving a great range of focal lengths from a good wide angle to a nice long telephoto. With the F3 your lens choices are currently much more limited. While there are some very nice zooms like the Optimo 24-290mm (12x zoom) these just are not practical for run n gun. The Optimo weighs a whopping 24lbs/11kg . The other alternative to PL lenses is to use a DSLR lens. One of my favourites is the old Tokina AT-X Pro 28-70mm as this does not telescope, has a nice big focus scale and proper iris ring, but it’s only a 2.5x wide zoom, not much use for longer shots. The upshot of all this is that you end up doing a lot of lens swaps going from a wide zoom to a longer one (Sigma 70-300mm in my case). In addition the DSLR zooms are varifocal so you can’t zoom during the shot as the focus will shift.

So… I’m running around with the F3 and a rucksack with a couple of lenses and my favourite Vinten 100 tripod, swapping lenses many times for different shots. There’s no one-push auto iris confidence check, no image stabiliser and the batteries don’t last as long. As I said, compared to an EX1 it was hard work. But, I was able to be creative. It was easy to introduce some nice foreground or background soft focus objects. To do gentle pull focuses and to generally get good looking shots as opposed to just getting ordinary looking shots.

When an aircraft is started things can get very busy. There are spinning propellors to be aware of, or dangerous jet blasts (not to mention the noise). Aircraft can taxi with no warning. At these moments I was able to stop down the iris a bit to give myself greater depth of field for a little bit focus tolerance. This is what I like about the F3. It’s got sensitivity to spare so you can pick and choose how much DoF you have.

By the time the second airshow (RIAT) came around I realised that constant lens swapping was costing me shots. So for RIAT I used a Nikon 18-135mm zoom. This 7.5x zoom gave a much better focal length range, but its a rather nasty lens in so much as it’s f3.5 – f5.6 so the aperture changes as you zoom and it’s not particularly fast. It also telescopes and extends a lot as you zoom in, so you can’t use it with a matt box. The focus ring has no scale and iris has to controlled using the MTF adapter iris control. So all in all not my favourite lens, but for this particular shoot it worked out quite well. One thing that did become apparent is that not having a super fast lens, on this particular type of project was not an issue. I could still get reasonable shallow DoF shots when wide and at f3.5. At longer focal lengths the DoF decreases anyway, so shooting at f4 or f5.6 still yields pleasing results.

The footage from the shoots does look good. It has a much nicer look to it than conventional ENG video. The shallow DoF adds a quality feel to the material. While I didn’t shoot as much as I would have done with a more traditional camcorder due to the extra time required for lens changes, focus checking and the need to use the tripod more often, what I did shoot looked better overall so a higher percentage of what I shot will probably make it into the final production.

So as for my original question.. was it worth the effort? Well I think the answer is yes. The F3 can be used for run n gun, but it’s hard work, however the results are worth the extra effort.

New Firmware for EX1R – v1.2 with Forward Planning MetaData.

Sony have released a firmware update for the EX1R. This includes a couple of minor bug fixes and introduces forward planning metadata capabilities to the EX1R. The PDW-700/F800 XDCAM HD camcorders have had forward planning metadata for some time now and the F3’s new firmware also allows for it’s use. It’s designed to allow the user the ability to upload clip naming data and other data to the camera quickly and easily prior to shooting by copying the metadata to an SxS card.

Clip names

User-specified characters can be displayed (MP4/AVI).

Planning metadata

Shooting with planning metadata is possible. • Planning metadata can be read from recording media inserted into a memory card slot. • The planning metadata to be read can be selected.

• Clip names based on names defined in planning metadata can be specified.

• Clip names can be specified in languages other than English.

• More shot marks can be added.

• Shot mark names can be specified in languages other than English.

• Shooting information can be reflected in planning metadata.

• Information contained in planning metadata can be viewed.

Picture cache recording

When recording was performed in picture cache mode (picture cache time: 13 to 15 seconds) with i.LINK output, the cache data in memory was sometimes not recorded. That problem was corrected.

Click Here to go to the download page. There are also minor updates for the EX1 and EX3 released June 11th 2011 with some extra SxS card compatibility added.

 

 

Motion “Judder” on the FS100 and other video cameras at low frame rates.

There have been a number of threads in various forums about the way the images from the new Sony FS100 appear to judder or stutter when shooting at 25P or 24P. Most of the complaints appear to be coming from PAL areas where shooting 25P is common. This is not an issue unique to the FS100, in fact motion judder is often more noticeable with video cameras than film cameras even though the frame rates and shutter speeds may be exactly the same. Why is this?

One of the key issues here and I believe a very strong clue to what is going on is that most complain that the issue is most pronounced in areas of high contrast.

Our visual system picks up edges and other areas of high contrast to detect motion, in areas of high contrast any non-smoothness of the images motion will be more noticeable. The higher the resolution/contrast or more precisely the higher the MTF of the camera system the more we will notice judder and stutter.  Just take fast motion in an Imax film as an example, it stutters like crazy.

The FS100 and similar high contrast/resolution cameras will appear to stutter at low frame rates more than a low contrast/low resolution camera. Edges in film are almost never instant changes from black to white, there is almost always some smoothing or dithering caused by the grain structure of film. So when you consider the FS100’s near complete lack of noise, which through it’s random nature will help mask judder and stutter and you have a worst case scenario. A camera with sharp edges and no noise.

Another strong contributing factor is the use of detail correction that adds a very definite, hard, non-motion blurred black or white edge around any areas of medium to high contrast, so unlike the very slightly dithered edges we would see in film we have instant light to dark or dark to light transitions occurring over a single pixel. In the case of a pan that hard edge is going to step uniformly from one position to the next, it won’t have any motion blur and it will increase edge contrast compounding the images judder as our visual system will notice these hard edges jumping from one place to the next.

The PMW-F3 although it uses the same sensor is less prone to this effect as it has a more sophisticated DSP and uses less detail correction and more aperture correction for image sharpening. Aperture correction blurs with motion as it is a type of high frequency boost and as you pan the camera the motion blur of the image reduces high frequencies so the amount of correction also drops thus helping smooth edges as you pan.

You also need to consider the results of watching 25fps video on a computer monitor typically running at 60hz. You will get judder as 25 does not go into 60 evenly, this helps explain why this “issue” is getting more airtime in Europe than in the US where 24P with pull up to 30P is common and of course 30P will display on a 60Hz monitor with no additional problems.

So in the case of the FS100 (or other cameras exhibiting this effect),  I would suggest turning off the detail correction circuits or at the very least reducing the detail level if you are shooting high contrast images or anything with a lot of motion. It would also be interesting to compare similar pans at different speeds with some gain added to see if that helps.

I don’t think this is, as claimed by some, to be camera fault, more likely a result of a very clean, detail corrected image. Even an EX1 or EX3 will do similar things if your detail settings are too high. It’s not unique to the FS100, just one of those things that can happen when you have sharp pictures. When I watched the Sony F65 4k demo film “The Arrival” I noticed a similar increase in motion judder compared to film, again I put this down to high edge sharpness catching my eye and making me notice the cameras motion more acutely. Ohh that F65 stuff looked stunning!

Night Flyers. Shot with PMW-F3 in Singapore

I’m currently in Singapore staying at Clarke Quay. Most evenings a group of radio control kite flyers from a local store (goflykite.com) bring out their illuminated kites and fly them in the local park. It’s very pretty and seemed an interesting thing to try and shoot with my F3. As I’m travelling light, trying (and failing) to keep within a 20kg baggage allowance, I don’t have a tripod and I’ve only got a couple of lenses, my trusty 50mm Nikon f1.8 and my Tokina 28-70mm f2.6 zoom. Most of this was shot with the Nikon lens at +6db. I really wish I had a tripod and a longer lens! I did a little bit of grading work here and there to balance out the very orange street lights a little.

 

Sonnet SDHC to SxS Adapter Review.

I recently reviewed the rather excellent Sonnet QIO I/O device that allows you to very quickly ingest material from SxS cards, P2 cards as well as SD cards to your computer. Along with the QIO I was sent a Sonnet SDHC to SxS card adapter to take a look at. Now I’m going to lay my cards on the table here and say that I strongly believe that if your going to shoot with an XDCAM EX camera you should be using SxS cards in order to get the best possible reliability. However as we all know SxS cards are expensive, although a lot cheaper now than they used to be, I remember paying £600 for an 8Gb card only 4 years ago!

So ever since the launch of the XDCAM EX cameras, users including me have been trying to find alternative recording solutions. I found that it was possible to use an off-the-shelf SD card to express card adapter (the original Kensington Adapter) to record standard frame rates on class 6 SD cards in the EX cameras.  However the SDHC cards stick out of the end of the generic adapters so you can’t close the doors that cover the card slots in the cameras. Following that initial discovery various companies have brought out flush fitting adapters that allow the use of SDHC cards. Then about two years ago Sony openly admitted it was possible to use an adapter in the cameras and released their own adapters (MEAD-SD01 and MEAD-MS01) as well as making some firmware changes that made using adapters more reliable. The key point to consider when using an SxS adapter and SD cards is that the media, the SD cards, are consumer media. They are produced in vast quantities and the quality can be quite variable. They are not made to the same standards as SxS cards. So I choose to shoot on SxS whenever possible and I’ve never had a single failure or unexplained footage loss. BUT I do carry a couple of adapters and some SD cards in my camera kit for emergencies. You never know when you might run out of media or find yourself in a situation where you have to hand over you media to a third party at the end of a shoot. SDHC cards are cheap and readily available. You can buy an SDHC card just about anywhere. I’d rather switch to SDHC cards than try to do a panic off-load to a backup device mid-shoot, that’s a recipe for disaster!

Sonnet-SxS-300x295 Sonnet SDHC to SxS Adapter Review.
Sonnet SDHC adapter for SxS Camera Slot

Anyway… on to the Sonnet SDHC to SxS adapter. It feels as well built as any other adapter on the market. It is mostly metal with plastic end pieces that are made from a nice high quality plastic. I have other adapters that use a very brittle plastic and these can break quite easily, but this one appears to be well made. The SDHC card slots into a sprung loaded slot in the end of the adapter making a reassuringly positive sounding click when it’s latched in place. Once inserted the SDHC card is slightly recessed into the adapter. This is good as it helps prevent the SDHC card from being released from the adapter as you put the adapter into the camera. It means that as you push the adapter into the camera you are pushing on the end of the adapter and not on the SDHC card like some other adapters I have used. To remove the SDHC card you simply push it quite firmly, further into the adapter until you hear another click and it then pops out far enough to be pulled out. This is certainly one of the better made adapters that I have come across.

To test the adapter I used some Transcend class 6 SDHC cards as well as some Integral Ultima Pro class 10 SDHC cards. I used the adapter in my PMW-F3 with firmware version 1.10 as some user have reported problems with other adapters and this firmware revision. I was able to completely fill the cards shooting using S&Q motion at 50fps or 60fps using long and short clips with lots of motion. This is I believe the toughest test for these adapters as the recording bit rate is close to 70Mb/s. I had no issues at all with either type of SDHC card and there was very little delay between finishing a recording and being able to start the next, a good indicator of the cards high performance. I also tested recording very long clips to ensure that there would be no issues when the camera breaks the recording into 4Gb chunks. Again, no problem.

So if you are going to use SDHC cards and an SxS adapter I would suggest you consider the Sonnet SxS adapter. It’s certainly cheaper than the Sony adapter. Sonnet are a large business with a wide range of products and a global distributor and dealer network, so you should have no problem finding a local supplier.

2x PMW-F3’s on my Genus Hurricane Rig.

Well I’m a happy chappy. Took delivery of my second PMW-F3 today so that I can shoot my 3D projects using a pair of F3’s rather than my EX1/EX3. Now I have a working lens converter that allows me to use standard 2/3″ broadcast lenses on the F3 the F3 is fast becoming my default camera for almost everything.  So the I took the decision to trade in my EX3 against a second F3. For lenses on the 3D rig I’m going to use DSLR lenses. Today I checked out my Nikon 50mm f1.8’s and these were just fine but my Tokina 28mm f2.8’s are un-useable as the lens optical axis shifts as you focus causing alignment errors, so I need to find some alternative wide angle lenses. I’d really like two sets of Zeiss PL mount Compact Primes, but that’s way beyond my budget. I might try and stretch to a couple of sets of Zeiss ZF.2’s, but I think that for the moment it’s going to have to be a case of building up pairs of lenses as I can afford them.

Replay XD1080 mini-cam.

replayxd1080-1-hero-300x221 Replay XD1080 mini-cam.
Replay XD1080 minicam

I like the Go-Pro, I also like the Sony MC1P, different tools for different jobs. The Sony MC1P has a built in screen on the end of an umbilical cable, so you can position the camera where you want it while viewing the pictures on the monitor. The Go-Pro can have a postage stamp size display clipped on to it’s back for framing, but this is next to useless when the camera is mounted in a tight spot where you can view it’s rear end.

Enter the Replay XD1080. This new POV camera (shipping at the end of the month) is small and compact, but the best bit IMHO is that it has an integrated HDMI output. This make plugging in a monitor, or recording to an external device like a NanoFlash nice and easy and makes this unit sound particularly versatile. In addition it will take an external microphone making it well suited to use in race or rally cars.

Looks like this will be a strong contender in the POV camera market. Only a few years ago minicams were few and far between and very expensive. Now we have lots of choice at great prices.