All posts by alisterchapman

PMW-F3 S-Log and Cinegamma quick look.

Hello from hot and steamy Singapore. I’m at broadcast Asia doing some presentations on the PMW-F3, FS100 and 3D. On the Sony booth they have a PMW-F3 with all the options installed including S-Log and what also appears to be the 3D link firmware (mission for tomorrow – investigate 3D link). So I decided to quickly grab a couple of test shots with both S-Log and Cinegamma 1 to see how much of a difference there was. I was only able to record to the internal SxS card, but the results were quite enlightening. This was all done very quickly, so it’s not particularly scientific or accurate, but it does prove beyond any doubt that S-Log brings a significant boost to the dynamic range compared to the cinegammas. I estimate it gives you between 1.5 and 2 more stops to play with. Given that the F3 is already tested and shown to have around 11.5 stops with the cinegammas, this means that the F3 with S-Log is in the 13 to 13.5 stop range, very impressive indeed.

The shot is a pan from the darker side of the Sony booth to the very bright camera set. Exposure was set using the bright end of the shot and setting the iris so that the hotspots  in the image were just below clipping, the idea being to look at what was going on in the shadows to get a feel for the dynamic range. Click on the images below a couple of times to get to the full resolution version if you want to see that.

Cinegama 1 Bright Part
S-Log, bright part, un graded.
S-Log bright part, graded.
Cinegamma dark part.
S-Log Dark Part

What’s most striking is the difference in the shadow areas in the S-Log footage. Given that the peak white exposures were roughly the same (108ire) there is a huge difference in the darker shadow areas with much more information in the S-Log. It also surprised me just how well the bright part of the S-Log clip graded. Do remember that these clips were taken from recordings on the SxS cards, so they are 8 bit, 35MB/s.

I’ve put together a sequence of these clips for Vimeo. Click Here to go to the video on vimeo. The final test that I did, which you will see in the vimeo clip is to try to grade the shadow areas of the Cinegamma to bring them up to match the S-Log. The result was nowhere near as pleasing as the S-log as lifting the blacks introduces a lot of extra un-wanted noise and it still does not have the contrast range of the S-log.

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 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.

Can you see the difference between a 8 bit and 10 bit camera output?

The question is can you see a difference between a camera with a 10 bit output and one with an 8 bit output? This is being asked a lot right now, in particular in relation to the Sony FS100 and the Sony F3. The FS100 has an 8 bit output and the F3 is 10 bit.

If your looking at the raw camera output then you will find it just about impossible to see a difference with normal monitoring equipment. This is because internally the cameras process the images using more than 8 bits (probably at least 10 on the FS100, the EX3 is 12 bit) and then convert to 8 or 10 bit for output so you should have nice smooth mapping of graduations to the full 8 bit output. Then consider that most LCD monitors are not able to display even 8 bits. The vast majority of monitors have a 6 bit panel and even a rare 8 bit monitor wont display all 8 bits as it has to do a gamma correction at 8 bits and this results in less than 8 bits being displayed. 10 bit monitors are very rare and again as gamma correction is normally required there is rarely a 1:1 bit for bit mapping of the 10 bit signal, so even these don’t show the full 10 bits of the input signal.  So it becomes apparent that when you view the original material the differences will not normally be visible and often the only way to determine what the output signal actually is is with a data analyser that can decode the HDSDi stream and tell you whether the 2 extra bits actually contain useful image data or are just padding.
Where the 8 bit, 10 bit difference will become apparent is after grading and post production. I wrote a more in depth article here: Why rendering form 8 bit to 8 bit can be a bad thing to do. But basically when you start manipulating an 8 bit image you will see banding issues a lot sooner than with 10 bit due to the reduced number of luma/color shades in 8 bit. Stretch out or compress 8 bit and some of those shades get removed or shifted and when the number of steps/shades is borderline to start with if you start throwing more away you will get issues.

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.

DCP Creation Software

Do you ever need to create a DCP (Digital Cinema Package)? Very often the only way to get a DCP put together has been to get a specialist company to do it for you. DCP creation software has been available for some time but it is normally expensive. There are various methods described on the internet that use different bits of software to do different aspects of DCP creation, but these are tricky to get right. This package however looks much more straight forward to use:  DCP Builder. The best bit is that it is completely free.

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.

Playing with lenses: 2/3″ Broadcast lens on PMW-F3.

OK folks. I wanted to see just how well a 2/3″ broadcast lens would work on an F3, but don’t have $5.5k to fork out on one of the Abel adapters. So with a bit of head scratching, a few, lowish cost lens purchases and a few hours in the workshop I cobbled together my own adapter. At first I tried a 2x magnifier but this didn’t quite give me full sensor coverage and was soft out in the corners. With a little more work I took the magnification up to 2.5x and I have clean corners. I’m really pleased with the performance, although one lens element needs changing for a higher quality element to combat some softness when the iris is fully open.

My old Canon J16x8 f1.8 becomes a 24 to 320mm f4(ish) par-focal lens which is actually quite handy. Next step is to make up a power cable for the lens so I can use the zoom servo.

I’m considering trying to find a manufacturer that can make these up for me properly, the converter should cost a lot less than $5.5k