Studio Camera vs Ursa Mini

Hi,

We are in the process of building a new church facility, am with that, we are investing in new live production gear. Our control room will consist of 4K ready blackmagic studio gear to where we would only be the cameras shy of being a full blackmagic setup. We've been attracted towards the Live Studio Camera 4K as our camera choice with a b4 mount to attach an eng lens to each camera. Our volunteers are use to those type of lenses as we currently use them in our current SD setup. At a recent expo we talked with a couple of lens manufactures regarding this and they had mentioned that the b4 mount crops the image and darkens the image down about a full stop. We also talked with blackmagic at this expo and without really selling us on the Live Studio Camera, they kind of pushed us towards us the Ursa Mini. I'm wondering if anyone has experience with both cameras with an eng lens and any other opinions you might have. We have used the Ursa Mini in the ef mount configuration, so we have some experience with that camera, just not in a live "studio" setting.

Thank You

While I have no direct experience of this, I have seen mentioned on these and other forums that the Ursa Mini has a high latency that makes it unsuitable for live to screen use. I would recommend a forum search on the subject to check.

The Ursa Mini 4K PL camera will work with HD B4 lenses using rhe BM B4 lens mount, that replaces the PL mount. That said, it does not shoot in 4K using the B4 lens, as the B4 lens is a 2/3rds CCD lens, and the Bm4K is a Academy 35mm size sensor, much larger, and with the corrected B4 mount, Dian only cover the sensor in a HD window mode.

The BM Studio 4K camera is a S16 size sensor, and corrected B4 lens adapters to MFT (studio camera mount) are available, but the type you need is $1500 to 3K in cost, with the AbdlCine adapters being the best bargain, on sale now. A simple, non optically corrected B4 to MFT adapter is not going to work, you will have lots of CA (soft image ) from the lens until you stop it down to f/5.6-8. With the Studio camera you are also going to have to get a power adapter to the B4 lens to use the zoom servos (Ursan Mini PL has B4 lens power/control connection on camera).

The Ursa Mini setup will allow ATEM CCU control of lens Iris setting and zoom, but focus will need to be done by camera operator. The UM and Micro Studio camera can also be color balanced by the ATEM to match images form several cameras, as can the BM Studio cameras.

If you are using a projected screen in the church, then all three cameras have varying amounts of video delay, Micro Studio 1-frame, UM 2-4 frames, and the ATEM 1-2 frames. Not sure on the BM Stuido, but probably 1-2 frames.
DS

Does the Ursa Mini B4 mount adapter have optics in it to sort out the CA in the same way that you need an optical adaptor for the Studio Camera?

Stephen, the B4 mount for the Ursa Mini is not an adapter, but an actual mount, that replaces the PL mount on the Ursa Mini. Yes, it does have an optical block in it to both correct CA issues caused by using a 3-CCD lens on a single sensor non-prism camera, and it also,expands the image a little to fill the HD/2K window of the camera.

For what it's worth, we use 2 x Studio Cameras HD and 2 x Micro Studio Cameras, all in HD into an ATEM Production Studio 4K or older 1M/E, mostly covering conferences. We have kept costs to an absolute minimum by using all but one Panasonic MFT stills lenses, mostly second hand: 14-140 x 2, 45-175 power zoom, 14-42 power zoom, 100-300, plus a 12-35 available which usually stays on a Panasonic DSLM for interviews and general production. The only non-Pansonic lens is a Sigma 170-500 Nikon mount with a cheap mechanical adaptor for coping with huge hangar-like halls (close-ups at 50m). This lens suffers a large crop factor so the close-ups are very big, but quality is not great.

There are clear pros and cons with this setup. It is cheap and all MFT lenses' iris and focus can be controlled from the ATEM, as can camera gain and colour balance. Power zoom can also be controlled on the relevant lenses from the ATEM and we use those on a cheap Bescor (sold under a number of brand names) remote head, whose simple 7-pin DIN plug control cable we have adapted to run over up to at least 90m on Cat5. This gives us for instance a camera to use in the front row of a conference with no operator.

At the same time, we were very clear about the cons when going for this approach. Only the two 10x lenses have anything like the zoom range of a TV lens, which means you have to think differently. For instance, in a classic huge UN debating chamber we had a Studio Camera on stage with the nearest delegate about 3m away and the furthest 30m away, so we actually changed lenses to get a close-up of either, which is possible in those circumstances because it is a slow-moving debate and we could see which delegate was going to be called next by the Chair. If you want a wide and a close-up from the same position you have to put in two cameras.

The other big constraint is low light. All the lenses apart from the 12-35 are f4-5.6, plus the cameras are not as sensitive as a typical TV camera, so we run all the time at 12dB gain at least, if not 18dB, and in the murky UN chamber we had to wind up the gain further in the colour correction. This does increase the noise and is the biggest problem; luckily the UN job was only for webcast, plus the client was none too critical. In a couple of recent jobs I have simply made sure that I was in charge of lighting and put in up to 3.5kW of lighting on my own lightweight rig. The annoying aspect is the change of f stop as you change framing, so you have to rack the iris constantly, which is easy enough on the ATEM remote control, and which overrides (AFAIK) the camera iris control. The exception again is the Sigma lens which is irised manually, but it is intended to sit on a speaker close-up with stage lighting, so apart from the occasional change of framing there is little need to iris changes.

Also you cannot zoom in vision because the lenses lose focus (except possibly the 14-140 - haven't tested it fully), which is not an issue for conference use as we mostly use cuts and no zooms or dissolves - proceedings are slow enough already so I believe in keeping the coverage snappy or it could become soporific.

So, having worked for 30 years with long zoom TV lenses we have had to adopt a completely different way of working, and plan carefully. I know that there is much criticism of BM's studio cameras but they work for us.