Switching base ISO mid recording in Cine-EI is causing some metadata issues in Resolve and perhaps other applications, so I strongly recommend you do not switch the base ISO mid shot.
DaVinci Resolve now reads the metadata from footage shot by the FX6 and FX9 in the Cine-EI mode to automatically add the correct exposure offset. So, shoot at 800 ISO base with the EI set to 200 and Resolve will add a -2 stop offset to the footage so that it looks the same as it did when you shot. Shoot at 800 ISO base and 3200 EI and again the correct +2 stop offset is applied.
However if you shoot at 800 base ISO, perhaps with 800 EI and then half way through the shot change the base ISO to high and 12,800 ISO, perhaps with 12,800 EI Resolve gets a bit confused. It will use the new base ISO but the original EI and as a result from the point where you switch base ISO the footage will look extremely under exposed.
So, if you must change the base ISO, it is better to stop recording, switch base and start recording again.
Tag Archives: Base
Chart of Sony Dual ISO Base Levels
Here’s a handy chart of the base ISO levels for Sony’s cinema line cameras including Venice, the FX9, FX6, FX3 and FX30 as well as the A7SIII and A7IV. The new Sony FR7 is the same as the FX6. I’ve include the base ISO’s for both S-Log3 and S-Cinetone. If you use other gammas the base levels may be different to the S-Cinetone base level, so these values should only be used for S-Cinetone and S-Log3. You can click on the image for a bigger version or left click on it to download it.
As explained above there is a difference in the way the dual ISO functions work between the FX6/FX3/A7SIII and the other cameras. Venice, the FX9 and FX30 have sensors with two distinctly different sensitivities. These cameras offer near identical performance at either the low or high base ISO. Sony call these cameras “Dual Base ISO” as in most cases the two base ISO’s can be used in exactly the same way depending on which best suits the light level you are working at and a near identical image produced.
The other cameras (FX6, FX3, A7SIII) probably have a dual gain sensor plus additional processing to deliver their 2 distinctly different sensitivity ranges. The result is that there is a more visible increase in noise at the high range (compared to the Dual Base ISO cameras) plus a very slight reduction in dynamic range. However, the noise level in the high base setting is significantly lower than you would have by adding gain to get to the same level and the upper base sensitivities are very usable and allow for shooting at very low light levels.
For more information on Dual Base ISO sensors take a look here: https://www.xdcam-user.com/2019/11/what-is-dual-base-iso-and-why-is-it-important/
Base ISO Levels for the FX9
First of all. Unless you are actually using a lightmeter to determine your exposure, in custom mode it is far, far easier to use dB of gain. 0dB is always optimum and each time you go up 6dB the picture gets twice as bright (one stop brighter) and the noise doubles. ISO is in most cases nothing more than a rating to use in conjunction with a lightmeter to get the right picture brightness, it will not tell you how much noise you have or whether the camera is at it’s optimum setting. So don’t use ISO just because “ISO is cool and make me sound like I know what I’m doing, it makes me a cinematographer”. This isn’t a film camera, no matter how much you dress it up it is a video camera and dB tells you exactly what it is doing.
Because different gamma curves produce different brightness images the ISO rating will change depending on the gamma curve being used, this isn’t a sensitivity change, it’s an optimum brightness change. Because of this, even when you are at 0dB gain (the native setting) when you switch between different gammas the ISO rating changes. In addition because you have two different base sensitivity modes on the FX9 there are a lot of different base ISO’s (all of which are 0dB gain). I’ve prepared a table of the different base ISO’s.
In addition if you are not careful it’s possible to end up using too much gain to achieve a certain ISO as many ISO ratings can be realised at both Hi and Low Base sensitivity. You don’t want to be at 2500 ISO in Low Base for example, you would be better off using High base. The table below should help you understand when to switch up to High base from Low base. If you use dB gain, then it’s easy. More than +11dB – switch up. Don’t forget in dB mode you can also go down to -3dB.
Vocas Sliding Base Plate System.
Let’s face it, camera base plates are not really very exciting things. But they are very necessary additions to most peoples kit, especially for any of the full size super 35mm digital cinema cameras. From Red’s to F55’s to FS7 etc, they will almost always need some form of base plate at some point.
So what’s different about the Vocas sliding system?
A complete Vocas sliding base plate system comprises two main parts. The first bit attaches to the camera and that will be either a generic flat camera mounting adapter plate or a custom camera mounting plate for cameras that don’t have flat bases, for example the FS7 or Venice where the adapter follows the curve or shape of the bottom of the camera.
The second part is a shoulder mount, shoulder pad or tripod plate or generic flat mounting plate that the camera adapter smoothly and securely slides onto.
One of the first benefits of this system is that you can easily alter the position of the camera relative to the base plate or shoulder pad. This makes balancing the camera on your shoulder or on a tripod much easier. A large red level locks the two sliding parts securely in place and there is a safety release catch that must be pressed if you wish to separate the mounting plate from the base plate, so they can’t come apart by accident. However if you need to move the camera forwards or backwards relative to the mounting plate all you need to do is release the large red locking lever.
Another benefit of the system is that it is very quick to reconfigure if you need to. For example many cinematography accessories are mounted using 19mm rails rather than the lightweight 15mm rails often used with ENG or smaller rigs. Perhaps you have been shooting handheld where a lightweight 15mm setup works better. Using the Vocas sliding system you can have a light weight base plate with a comfortable shoulder pad, 15mm front and rear rails that will clip in and out of a VCT style quick release tripod plate attached to the camera for your handheld shots. Then when you need to go to a bigger lens perhaps and 19mm rods, you simply slide off the 15mm base plate and slide on the Vocas 19mm plate. Quickly transforming the camera into a heavy duty rig that will then attach to an Arri style tripod plate. Need to keep the 19mm rods but now need a shoulder pad? Well that’s easy too as there is a matching shoulder pad for the 19mm base plate. It’s all very quick and very easy.
It also means that if you have multiple cameras all you is a mounting plate on each of your cameras then you can use the same base plate on all your cameras just by sliding it on and off as needed, or swap between lot’s of different types of plates depending on your needs.
If you don’t need a base plate with rods etc and just need a quick way to mount your camera to a tripod then there is also a basic tripod adapter that the camera can be slid directly onto. This gives you a really secure, quick release, low profile mounting system that is free from the wobble that often plagues other quick release mounts. It’s ideal for crash cams, car mounts and car rigs. Or for those situations where you just need something quick and compact. This would also help keep the weight down for use on gimbals or perhaps a stedicam. Need to go back to a shoulder mount or full tripod rig with rods, just slide the camera off the tripod plate and slide it on to your preferred 15mm or 19mm shoulder plate.
Nice touches on the VCT type base plates are the adjustable height rod mounts and also an adjustable tensioner for the rear mounting spigot. Normally on a VCT base plate the rear spigot doesn’t do a great deal to add stability to the system, it just helps to loosely locate the base plate. However Vocas have added the ability to put some tension on to the rear spigot to help pull the camera down onto the VCT plate. This can greatly decrease, if not eliminate the wobble and flex that is all to common with these quick release plates.
Another really nice touch is that the attachment screws for the mounting plate and an allen key for adjusting the height of the rod mounts can be stored inside the base plate so you should never loose them.
Any downsides? Well yes, any 2 part system like this is going to be a little more complex with more parts and a bit more metal than a basic fixed mounting plate, so the sliding base plate ends up a touch heavier than the equivalent fixed position base plate. It’s not a big difference, but it does add a bit of weight. However in most cases I believe it’s worth it. Especially if you are swapping between 15mm and 19mm systems frequently. Being able to quickly and easily re-balance the camera when handheld and you change lenses is very nice.
If you have more than one camera it makes it easier to share different mounting systems between them. So while the initial cost may be a bit more, in the long run you only ever need to add new mounting adapters to keep using all the different base plates you have with extra cameras or new cameras.
As always with Vocas products the quality of the engineering is first class. The parts fit together beautifully. Only high quality materials are used and the finish is very nice. So if you are looking for a really nice base plate for your camera – or cameras – do take a look at the Vocas sliding system. It’s really very well thought out and something that will last for a very long time.
Disclosure: I have a good relationship with the guys at Vocas. I had been shown this system at various trade shows and it looked interesting, so I approached Vocas for the loan of a review system so I could write this article.
Vocas PMW-F5 and PMW-F55 Shoulder Rig. Really Nice Stuff.
I’ve been using various shoulder mounts for my F5 over the last year. They have all worked well for me. But at CabSat in Dubai I was lent a Vocas shoulder mount and handles to use with one of the F55’s I was using on the Sony booth.
Now, I’ve come across Vocas many, many times before, they are not new players in this arena and thier products have always looked to be well thought out and well made, but when I put the F55 rig on my shoulder and my hands wrapped around the beautifully carved wooden handles I just fell in love with it. When you use a camera day-in, day-out, how it feels in your hands or on your shoulder is really important and it’s amazing how a great shoulder rig can make using a camera a much more enjoyable experience. A bad rig will make using the camera a miserable chore.
So what is it about the Vocas rig I like so much? First of all it’s a fully modular system so you can buy just the bits you want or need. Many of the parts will work with other systems. Initially I just got the shoulder mount and hand grips, but after using these for a short while I realised I also wanted to replace the existing top plate and somewhat uncomfortable carry handle that I had been using with the Vocas one, so I added the top cheese plate and carry handle to my rig this week.
The thing that got my attention when I borrowed the rig back in March was the comfort of the handles. The carved wooden hand grips were developed in association with Cam-A-Lot, one of the larger high end cinematography rental houses in Europe. So they know their stuff and know what camera operators want. The design is simple but beautifully executed, a carefully shaped handgrip with an Arri style rosette. The top of the grip has a notch/extension that your thumb wraps around making your grip really secure, this won’t slip out of your hands by mistake. You don’t have to hang on to these handles, your grip is secure even with very light pressure. Your fingers wrap around smooth grooves in the front of the grip and it’s hard to explain, but it just “feels right” and wood is much nicer to hold than plastic or rubber (Vocas also make leather hand grips).
The hand grips are then attached to some extension arms and these arms then attach to the base plate. Again the design of the arms is really simple, but sometimes simple is really effective and these arms are really really light, yet very, very stiff, the quality and finish of the alloy used is excellent. You can join any Vocas arm to any other Vocas arm to create different angles and lengths and there is a range of different arms of various lengths and offsets to choose from. I’ve ended up with one short straight arm and one longer offset arm. Using these two arms I can configure the rig several ways.
Using just the short arm I can place the right hand grip up alongside the lens for a very secure and very comfortable single handed ENG style shooting rig. There is no need for the strap that you have on the hand grip of an ENG lens. The wooden grips are so easy to grasp and so secure that you just don’t need that extra strap around the back of your hand. I could use the longer offset arm, mounted on the right side and offset to the left to place the hand grip under the lens for an alternative single handed rig.
By using the short arm on the right, angled down and the longer offset arm on the right angled down I can create a two handed rig. One thing I did find is that if you mount the single arm sections that I have on the rosettes on the shoulder mount the handles are quite close to your body. If you prefer your hand grips a little further away from your body you have a couple of options. Either double up on the arms joining two together to make a longer articulated arm, or do as I did and add the 15mm rail bracket that has a rosette at each end to mount the handles from the rods (Vocas also do a 19mm system). The rail bracket has a very neat quick release catch, so it’s a breeze to fit.
But what about the shoulder mount that all this is hanging from? The one I have is the Vocas standard PMW-F5 and F55 base plate. Now, this doesn’t look anything special, but looks can be deceiving. This very comfortable base plate weighs only 600g. That’s quite a lot lighter than my previous base plates and lighter than the Sony equivalent. It’s a VCT-14 compatible plate so snaps in and out of the very common Sony quick release plate quickly and easily. If you don’t want VCT-14 compatibility the silver part with the VCT wedge in the picture above can be replaced with a flat plate for mounting directly on to tripods or other mounting systems.
The base plate can be slid forwards and backwards relative to the camera body to help you achieve perfect balance. The mounting screws run in a slot with deep shoulders that make the plate very ridged and secure. The comfortable soft shoulder pad can also be moved forwards and backwards within the base plate giving you further flexibility. On the sides of the base plate are a pair of Arri style rosettes and at both the front and rear there are holes for the usual 15mm rods.
Moving on to the top of the camera….. The comfort of the carry handle is so important, especially when the camera is rigged up with weighty accessories and heavy batteries. The last thing you want is blisters on your hands from a bad handle. So after experiencing the comfort of the hand grips I decided to add the Vocas top cheese plate and handle.
The handle has a very nice wooden grip insert which makes the camera very comfortable to carry. You also get a pair of posts to take a standard Sony shoulder strap. Oh Joy! Sony take note: please include provision for a shoulder strap on all your cameras, they are very useful! The top cheese plate is well… a cheese plate with lots of mounting holes for all your accessories. It’s very slightly raised from the top of the camera body to avoid inhibiting any cooling of the camera. The handle takes a mounting bush for the F5/F55 viewfinder that can be placed either at the front of the handle or on the rear. This is handy for film style shooting from behind the camera rather than to the side. You can also use a pair of 15mm rods attached to the handle that run above your lens if you need to mount a Matte Box from above or add extra items like follow focus motors. Integrated into the handle is a pair of cold shoes for accessories such as a camera light. If you have a very heavy lens, like perhaps the new Canon 17-120mm or a Cabrio then the handle can be mounted facing forwards to get better balance.
The last part of the kit is the optional side cheese plate. This serves two purposes. The main one for me is to protect the rather vulnerable viewfinder connector that sticks straight out from the side of the camera body. With a list price of just 95 Euros, this is a really wise investment (if you don’t use a cheese plate etc why not get one of my plastic viewfinder connector protectors that I sell on ebay). The other purpose is to provide yet more 1/4″ threaded mounting points on the side of the camera. I think it also looks cool! A small observation is that the rather flimsy connector still protrudes beyond the cheese plate by about 15mm, so bash it into a door frame walking through the door way and you could still damage the end of the connector. So I’m going to add a 1/4″ bolt to one of the threaded holes in front of the connector. This will stick out a bit and further protect the connector from damage.
So while a shoulder rig might not be the most interesting part of your camera kit, it is one of the most important. It’s what connects you to your camera, or what connects your camera to your tripod. If it isn’t comfortable, your camera will feel awkward. A bad rig might compromise your shots or shooting style, so getting the right rig is important and I can highly recommend Vocas as a supplier of shoulder rigs and associated support equipment. If you get the opportunity, do try the wooden hand grips. They are a bit more expensive than most plastic or rubber based hand grips, but they are just so nice to hold. Using this rig is a delight, I love my PMW-F5 and this rig makes it very easy and comfortable to use.
FYI. The Matte Box is one of the new Alphatron Matte Boxes. A review of which will be on-line very soon. It’s nice! The follow focus is an Alphatron ProPull, a great little compact follow focus with adjustable end stops for fast focus pulls. The lens is a Samyang Cine Prime. Based on a DSLR lens but with pitch gears and smooth aperture adjustment. Great image quality and T1.5.
Bottoms Up! New Base Plate Assembly for the PMW-F3 from Transvideo.
A package arrived in the mail from Transvideo the other day. In it was one of their rather nice base plates for the PMW-F3. This plate isn’t simply a plate that it is attached to the bottom of the camera. It is in fact a complete replacement for the bottom end of the PMW-F3. Transvideo are best known for their superb high end monitors, robust, built to last monitors you often find on movie sets as they they offer a range of highly accurate calibration tools and fully calibrated displays not found on many lower cost monitors. In addition Transvideo’s 3D monitors are the monitors of choice for many 3D productions and stereographers as they offer special monitoring options that allow for very accurate measurement of 3D offsets and geometry. This new base plate is a bit of a departure from Transvideo’s normal product lines. I suspect it’s come about because Transvideo’s 3D expertise led them to realise that one of the PMW-F3’s biggest issues for 3D is that the standard base plate isn’t particularly stable which can adversely affect alignment when used on a 3D rig.
This is a problem not only for 3D but also for use with long and heavy lenses as the camera can wobble and flex on the tripod. The two 1/4″ threads on the F3 are far from ideal and the third thread at the back of the camera is offset from centre making it hard to use. By replacing the original very thin base plate of the camera ( it is is really, really thin) with this much more robust base plate you spread the loads imparted on the tripod mounting points across the entire bottom end of the internal chassis of the F3, not just the 4 teeny tiny screws that hold the sony tripod mount in place. Fitting is very easy, 8 small screws are un-done to remove the original Sony base panel, which simply lifts off and then the new Transvideo plate, complete with beautifully CNC machined cooling slots simply attaches in it’s place. Now my F3 has a perfectly flat base with both 1/4″ and 3/8″ threads (hooray!!) as well as a large number of M4 threads towards the outside. Now I can fit standard Arri accessories without having to fudge together different plates and screws to make them fit.
Frankly this is how Sony should have done this in the first place, but well done to Transvideo, now my F3 is really starting to feel like a proper camera. The only very minor down side is that you loose your serial number plate as this is attached to the original Sony part. The fit is superb and it looks great too. The list price is €265.00. 10/10.
As well as the base plate I also received a little finger tab that attaches to the Sony PL mount. this little wing tab makes it much easier to remove and attach PL mount lenses as you can grip the lens with one hand and push the tab with you thumb to release the locking ring. It’s only a small thing but it makes the F3’s PL mount much more user friendly.
For more info on Transvideo products, click here.
Juice Designs EX1R base plate. Curtis does it again!
I had one of Juice Designs base plates on my EX1 and it was fantastic. It never came off the camera and gave me the confidence that any loads exerted on the base of the camera were spread over the entire EX1 base rather than the weedy single 1/4″ screw hole on the bottom of the EX1. When the EX1R arrived things were somewhat improved as now instead of one weedy 1/4″ thread there are two weedy 1/4″ threads. Great you think, two is better than one, but the little postage stamp sized plate that has the tripod mounting holes is attached to the EX’s chassis by 4 teeny tiny screws. These have a tendency to work loose over time and can break quite easily if over stressed. If you really load up the tripod mount you can fracture the casting or worse still the chassis of the camera. If all that isn’t bad enough the other issue I have with my EX1R in particular is that the tripod mount casting is very slightly proud of the base of the camera, so when its on a tripod (or my 3D rig) it wobbles about quite a bit as there is only about 1 square inch of metal in contact with the tripod. Clearly none of these are desirable and that’s where the Juice designs base plates come to the rescue. The EX1 version is attached to the base of the camera in four places. The obvious 2 are the normal pair of 1/4″ tripod threads. The other two are a couple of small screws that normally hold some of the plastic camera body parts on to the chassis. By spreading any loads across much more of the base of the camera the tripod to camera interface will be much stronger. In addition the camera is now rock solid on my tripod and 3D rig. If anyone is thinking of using an EX1 or EX1R on a 3D rig a base plate like this is not an option, it is absolutely essential!
The base plate is machined from a single piece of aluminium and anodised black. It is clearly a well though out design with nice curves that make follow the contours of the camera, indeed it looks like it really is park of the camera. It even has small recesses in it to clear some of the lumps and bumps that are on the base of the EX1R. At the rear of the base plate there is a small cut out area that allows you to add an optional bolt on accessory arm or “wing”. You can use the arm to attach devices such as the NanoFlash or Radio Mic receiver. The arm is supplied with a cold shoe mount which can be attached in a variety of positions making it very flexible indeed.
It took just minutes to fit the plate. It comes with all the screws that you need plus a couple of allen keys. You will need a small jewellers screwdriver to remove two small screws from the base of the EX1R. This is a high quality product that should help protect you investment and make the camera more stable, so highly recommended. See Juice Designs web site for more information.
