FS7: New Sony F7 XDCAM 4K Super 35mm Camcorder

[cuervo]

So many variables involved for anyone to really make a pronouncement on the best format to use. And even if you could, nothing ever stays the same, things change, things move along. The ENG/news gathering folks love the smaller sensors because DOF is not important, but, being able to carry, shoulder and shoot the smaller optics are certainly an important consideration. Another criteria would be rugged reliability to withstand being slapped around in the field and still come back able to dependably acquire.

Having said this, two caveats come to my mind. First, anything made inexpensively( hate to use the word cheap, but, plastic does come to mind) is not going to withstand the rigors of daily, 24x7, jostling around in the back of a news gathering van. Second, 4k really isn't in everyone's livingroom, yet. If and when this DOES happen, 1/3 inch sensors are going to really be hard pressed to produce 4K resolutions. For the times that are coming, s35 is the answer. In fact, it's been said that to really deliver 4k content, a 6k sensor is what's required. So, even more resolving power needed from those sensors. Not out of line with the s35 footprint, but, not in the cards for a 1/3, or probably even a 1/2 inch sensor.

I'm with you, Mitch. Give me a robust platform, with lots of adaptability, and you're on the right track. PL mount, variable capture DI's, modular systems able to update modules and keep the foundation platform, able to be uilt up into a number of different configurations. are where things are headed. And I'll add the observation that a programmable FPGA/CPU keeps obsolescence at bay, able to update via firmware when technology advances. While $20-30K looks expensive, amortized out over 5 years looks a lot cheaper than a new $10k camera every 18 months.And I would venture to say that the business end of newsrooms take a close look at hardware expenditures. Go visit an newsroom, sometime. Take a close look at how beat up those older JVC cameras look, and they still work, and they're still on the job. Something, I would opine, that an FS700 or FS7 could never stand up to.And as a side note, it must drive Sony crazy having to maintain firmware and hardware for a legacy of cameras, not to mention what that must cost them in operating expenses.

 

[harddrive]

A J20 might be impossible for S35 if it has to be fast as the same time, ........

True..... but does such a lens have to be as fast?

Before you hit the "reply" button to tell me how stupid that remark is (which it seems to be... on the face of it!) then hear the complete argument, I'll say again what I put in another thread.

If camera A gives the same performance (s/n) at ISO 2000 as camera B at ISO 500, then isn't it irrelevant if you use (say) an f5.6 lens on camera A, or a f2 lens on camera B? Their low light performances will be equivalent.

And (*with all else equal*) this is the situation here. For a given size of lens front element, it may be f5.6 if the lens is engineered for s35, but f2-2.8 if engineered for 2/3". But (and I stress with all else equal) a bigger sensor will be inherently more sensitive (bigger photosites).... so for performance it's back to square one - the two combinations should be equivalent. (And that's true for dof as well - smaller f stop/bigger sensor, the two cancel out.)

Which optically is what happens when using a B4 lens with an adaptor.

One fly in the ointment - above I stressed the "all else equal", and practically the aspect that will likely be different is the 2/3" camera will be 3 chip, the s35 single chip. Practically, this gives the 3 chip camera an advantage of about a stop, regardless of relative sensor sizes. It also assumes the s35 camera is either with a 1920x1080 chip, or is 4k used in 1080 mode - but just because a camera is capable of 4k, doesn't mean it has to be used as such. For news, it's not likely to be.

Accept all that, and with the right ergonomics, there is no technical reason why an s35 camera with B4 lens and adaptor shouldn't rival a conventional 2/3" camera in terms of performance/size/weight/zoom range. True, (because of the single chip nature) it will have a one stop disadvantage - but same would be true of single chip 2/3" such as the HPX600. Some might think the flexibility of being also able to use fast primes (to gain even better low light performance than a 2/3" combo, and/or shallow depth of field) on occasion is worth that.......

 

[Viddovation]

I know lots of news shooters who are using cameras like the F5 and F55. In fact, the Newsshooters themselves (as in the website), Dan Chung and Matt Allard, both use Super-35 sensor cameras for their work every day. And there are plenty of others. Not all "news" work is spot news, with a reporter live on the scene. In fact, most of it isn't. The vast majority of it isn't. There is plenty of work where the form factor of an FS7 or an F5/F55 would be very useful.

Sony is not stupid. The biggest advances and most models have been coming in the S35 sensor arena. Sony clearly sees the future as 4K yet has not released a 4K 2/3" camera. They are selling a LOT of product in the S35 sensor market. There is a lot of use for these cameras.

I easily beleive the F5, F55, and FS7 have appeal to ENG shooters, but I don't beleive they have significant penetration in the majority of news outlets. I easily beleive there is appeal for marketing and promo pieces to be shot in S35, and I know a Nashville affiliate that uses the Blackmagic line of cameras for it's promo pieces. I would willingly beleive the documentary style longform news shows like 60 Minutes would jump on the F5/F55 look and workflow, but I have a very hard time beleiving that these S35 cameras really can or will replace 2/3 ENG cameras in news shops.

Indeed, many news stories are not spot news. But at least in the shops I've seen there tends to be a promo department, an investigates department, a sports department, and a general photo pool. Each photo pool shooter is assigned a camera, and they have it with them always, even take it home with them, so they can always be dispatched. Even if a particular photo pool photog is generally given the feel-good pieces, he may very suddenly be expected to cover spot news if he's the person who can be dispatched the fastest when the spot news occurs. This means he must carry a spot news camera at all times.

Perhaps in Top 10 markets there are more specialists, but at the top 30 level, this is what I see.

4k is certainly the future, but the news stations will go into it kicking and screaming. I worked a Top 30 CBS affiliate as they made the HD transition. They upgraded the transmitter, the studio, and the promo department first, then waited nearly 3 years to transition the general photo pool from Beta SX with linear tape-to-tape editing to HD tapeless. And you bet your rear end, for those three years they were transmitting in HD from the studio they ran huge promos about being high def, even though every field package and live shot was SD.

The same will happen with 4k eventually - shops will upgrade the studio and transmit facilities first, and the field cameras last.

S35 optics are problematic for spot news. Shallow focus, zooms are either huge and heavy or have a slow aperture... all in all, poor for night based ENG work. And 4k requires more photosites, reducing sensor light sensitivity. So there are reasons we haven't seen 2/3 4k cameras... they aren't really in demand.

As for the argument that ENG cameras and S35 cameras both have setup time for spot news... An experienced ENG op has the button locations memorized, and many of these settings can be flipped while literally walking or running, without even looking at the camera. Final iris adjustments can be made in mere moments. An ENG camera can be powered and shooting in under 5 seconds, if conditions demand. For spot news, it's about "the shot" and you can't afford to miss the shot by switching lenses or being out of focus.

 

[Alpha Beta Omega]

One can argue about how S35 cameras in general and in this case the FS7 suits as ENG style cameras. With the improved form factor of the FS7 what it now need is a good lens in order for that to happen. It doesn't have to be super fast but F4 and above wont cut it if the lens doesn't have at least a 15x zoom.

One could use a B4 lens in extender mode loosing 2 stops of light and use a 18x13mm area of the S35 sensor but that is a major compromise. Will it look good enough? No it wont be sharp enough to take full advantage of 4k or even 1080 if looked close. Other than B4 lenses there aren't many options. Not to mention the hassle of getting a B4 lens to communicate with the hand grip on the FS7.

I wish such a lens in native E-mount comes. As said it can be a F4 lens like the 28-135 from Sony but with a greater focal range. Any slower and you will miss the look that a S35 camera brings.

On the other hand you could use a Sony 18-200 PZ lens which looks good but it's to short in range and very slow in low light.

 

[cuervo]

4k is certainly the future, but the news stations will go into it kicking and screaming. I worked a Top 30 CBS affiliate as they made the HD transition. They upgraded the transmitter, the studio, and the promo department first, then waited nearly 3 years to transition the general photo pool from Beta SX with linear tape-to-tape editing to HD tapeless. And you bet your rear end, for those three years they were transmitting in HD from the studio they ran huge promos about being high def, even though every field package and live shot was SD.

The same will happen with 4k eventually - shops will upgrade the studio and transmit facilities first, and the field cameras last.

S35 optics are problematic for spot news. Shallow focus, zooms are either huge and heavy or have a slow aperture... all in all, poor for night based ENG work. And 4k requires more photosites, reducing sensor light sensitivity. So there are reasons we haven't seen 2/3 4k cameras... they aren't really in demand.

You sure called that one right. Just like the transition from SD to HD, the change will be slow and painful. But, there are factors that will really put the competitive pressure on stations. REC2020 is the new standard for 4K. 4k is not only about resolution, but, also color gamut. So, even if in-the-home sets stay at current physical sizes, color gamuts are projected to increase dramatically per REC2020. I think it's called "2020" because that's when all this 4K stuff is supposed to become commercially viable. And it'll take another 5 years for stations to yield to the competitive pressure. There are few cameras currently available that output in REC2020. So, we'll see a lot of post production remapping of colors, via a LUT to REC2020, unless coming from RAW files. All these 2/3 cams that output REC709 will not make the grade. And manufacturers, like Sony, are focusing development on s35. A single platform that can function in s35, or shoot s16 via sensor cropping, is flexible enough to meet a lot of needs.

 

[Viddovation]

One cam argue about how S35 cameras in general and in this case the FS7 suits as ENG style cameras. With the improved form factor of the FS7 what it now need is a good lens in order for that to happen. It doesn't have to be super fast but F4 and above wont cut it if the lens doesn't have at least a 15x zoom.

One could use a B4 lens in extender mode loosing 2 stops of light and use a 18x13mm area of the S35 sensor but that is a major compromise. Will it look good enough? No it wont be sharp enough to take full advantage of 4k or even 1080 if looked close. Other than B4 lenses there aren't many options. Not to mention the hassle of getting a B4 lens to communicate with the hand grip on the FS7.

I wish such a lens in native E-mount comes. As said it can be a F4 lens like the 28-135 from Sony but with a greater focal range. Any slower and you will miss the look that a S35 camera brings.

On the other hand you could use a Sony 18-200 PZ lens which looks good but it's to short in range and very slow in low light.

The fundamental element that people tend to value in S35 is the shallow depth of field. As I've already pointed out, shallow depth of field can be a serious nuisance for ENG work, because you're shooting people and story elements that aren't scripted and that you can't control. You can stage certain elements (ie, interview locations), but if you stage too many elements, you run the risk of not remaining an objective observer and becoming a participant, changing the course of events. It's an ethics issue.

But there's a related point here about depth of field. Shallow depth of field is a powerful storytelling tool, because it controls and directs the attention of the audience. Framing does this to an extent - choosing a closeup over a wide certainly directs attention, but shallow depth of field exerts a whole different level of control. In movies this is great. In news, it raises an ethical question. Should the camera operator intentionally focus on one element of a story to the exclusion of another? Deep depth of field puts everything in focus, and allows the audience to choose which elements in the frame are important. Just as news should try and relate important events with as neutral a bias as possible.


On a more technical note - I'm not sure you realize exactly how heavy and expensive S35 optics have to get for both a long zoom range and a fast, constant aperture. Gets pretty unwieldy, and expensive.

 

[harddrive]

The fundamental element that people tend to value in S35 is the shallow depth of field. As I've already pointed out, shallow depth of field can be a serious nuisance for ENG work, ...........

All true.... but large sensor=shallow depth of field *ONLY* for wide aperture. Use an f stop 2-3 stops smaller and dof will be the same.

On a more technical note - I'm not sure you realize exactly how heavy and expensive S35 optics have to get for both a long zoom range and a fast, constant aperture. Gets pretty unwieldy, and expensive.

Again, true as far it goes.... but I go back to the points I made in post 382. Bigger sensor means higher ISO rating for the same quality. Higher ISO rating means smaller f stop. Smaller f stop means same depth of field as 2/3", and same size lens as for 2/3". (Or just use a B4 lens with adaptor.)

What is being completely ignored in this argument is the fact that a bigger sensor will mean a higher basic ISO. So a smaller f stop will just put you back to square one cf 2/3" in respect of low light usage and dof.

Optically, if you adjust iris, zoom and focus with a B4 lens on a 2/3" camera, then put it on an s35 with adaptor without further adjustment, it will behave identically. Same angle of view, same depth of field.

Operationally, you shouldn't be able to tell which is which.

 

[rob norton]

But there's a related point here about depth of field. Shallow depth of field is a powerful storytelling tool, because it controls and directs the attention of the audience. Framing does this to an extent - choosing a closeup over a wide certainly directs attention, but shallow depth of field exerts a whole different level of control. In movies this is great. In news, it raises an ethical question. Should the camera operator intentionally focus on one element of a story to the exclusion of another? Deep depth of field puts everything in focus, and allows the audience to choose which elements in the frame are important. Just as news should try and relate important events with as neutral a bias as possible.

Shallow depth of field doesn't raise ethical questions. If an operator uses focus to craft a bias news package, that person's ethics are in question, not the sensor size. It's up to the news station to gain the trust of its viewers. A working photog (supposedly) is there because of their fair storytelling ability (plus technical ability). There is trust that they're not abusing their position. "Should the camera operator intentionally focus on one element of a story to the exclusion of another" - this is exactly what framing is. You decide what to show and what not to show in each situation. The job of the news shooter is to choose what is and what is not important for a story to show viewers. If this task becomes unimportant then they essentially have no purpose. I doubt there are many sneaky news photographers shooting everything wide open to trick people. I think you have to give audiences the benefit of the doubt in their ability to recognise a bias piece.

I agree that news should try and relate important events with as neutral a bias as possible but I think we have to be careful not to blame storytelling tools, rather, we need to hold the people telling to stories accountable.

 

[Viddovation]

All true.... but large sensor=shallow depth of field *ONLY* for wide aperture. Use an f stop 2-3 stops smaller and dof will be the same.

I just did careful comparisons using charts and calculators, and to get an equivalent depth of field on an S35 sensor to that of a 2/3 sensor, it takes approximately six stops on the aperture.

Tools:
http://www.abelcine.com/fov/
http://www.dofmaster.com/doftable.html

Two or three stops down on an S35 sensor will only get you a fraction of the way to 2/3" style depth of field. When you do your calculations, remember to determine the equivalent focal length on the two systems to get the same field of view (50mm S35 = 19.3mm 2/3").

Running glass at T16 and T22 is not running it at the optical sweet spot, generally speaking, so if you want 2/3" depth of field, you're better off using a sensor that size, and a lens built for it.

Yes, a larger sensor gets you more light. But 2/3" systems tend to use a prism, and have three chips, one for each color. A 35mm single chip bayer sensor is very lossy because any given location can only receive one color type of light. In essence, a 2/3" prism system is going to be 3x more effective at light gathering than a bayer single chip sensor.

 

[Viddovation]

Shallow depth of field doesn't raise ethical questions. If an operator uses focus to craft a bias news package, that person's ethics are in question, not the sensor size. It's up to the news station to gain the trust of its viewers. A working photog (supposedly) is there because of their fair storytelling ability (plus technical ability). There is trust that they're not abusing their position. "Should the camera operator intentionally focus on one element of a story to the exclusion of another" - this is exactly what framing is. You decide what to show and what not to show in each situation. The job of the news shooter is to choose what is and what is not important for a story to show viewers. If this task becomes unimportant then they essentially have no purpose. I doubt there are many sneaky news photographers shooting everything wide open to trick people. I think you have to give audiences the benefit of the doubt in their ability to recognise a bias piece.

I agree that news should try and relate important events with as neutral a bias as possible but I think we have to be careful not to blame storytelling tools, rather, we need to hold the people telling to stories accountable.

If you'll reread my statement, you'll see that I specify that depth of field and framing can raise ethics issues, not that they necessarily do. Nor am I saying news photogs should never use shallow depth of field. I'm pointing out legitimate ethics issues that can arise, and how the tools used can be party to it, either by intent or accident. Bias and angle always exist, in every form of journalism. One man's "terrorist" is another man's "freedom fighter", one outlet's "disturbance" is another outlet's "riot", one man's "Crusader" is another person's "religious nut". Just as words have power, so do images. We have choices when we frame to reduce bias, and to increase it. When we choose angles, both for the camera and the story, we're deciding what's important for the viewer to know. Even if we don't mean for it to, this involves a transfer of bias. Deep depth of field increases the audiences ability to try and find elements in the frame that the shooter didn't intend to highlight. It reduces bias. It preserves information. More information, more elements in focus, means more points of interest and detail for the audience to choose to focus on.

 

[rob norton]

If you'll reread my statement, you'll see that I specify that depth of field and framing can raise ethics issues, not that they necessarily do. Nor am I saying news photogs should never use shallow depth of field. I'm pointing out legitimate ethics issues that can arise, and how the tools used can be party to it, either by intent or accident. Bias and angle always exist, in every form of journalism. One man's "terrorist" is another man's "freedom fighter", one outlet's "disturbance" is another outlet's "riot", one man's "Crusader" is another person's "religious nut". Just as words have power, so do images. We have choices when we frame to reduce bias, and to increase it. When we choose angles, both for the camera and the story, we're deciding what's important for the viewer to know. Even if we don't mean for it to, this involves a transfer of bias. Deep depth of field increases the audiences ability to try and find elements in the frame that the shooter didn't intend to highlight. It reduces bias. It preserves information. More information, more elements in focus, means more points of interest and detail for the audience to choose to focus on.

Sure ethical issues through depth of field can arise - whether they actually do and cause a single real problem remains to be seen.

A shot with a shallow depth of field does not have less information, it has different information. It's not about having as many points of interest as possible. If shallow depth of field reduces a distracting background and lets us pay attention to the details on a sad person's face, sure there are less points of interest, but you might have increased the quality or weight of a single point of interest. If the audience has too much to choose from, they'll likely take away nothing of substance.

An audience can acknowledge and appreciate subtleties within a shot or story but that's different to seeking elements they think the shooter missed.

I recently used a GH4 for a short documentary. Any larger a sensor would've been a nightmare while walking the streets. I chose it because of the manageable focus not because it's a bias reducer.

 

[hscully]

On a more technical note - I'm not sure you realize exactly how heavy and expensive S35 optics have to get for both a long zoom range and a fast, constant aperture. Gets pretty unwieldy, and expensive.

This is just true. The S35 sensor size insists that you move the camera close to the subject. That's what it's designed for, cinema style shooting. Doc shooting, interviews, anything where you can move the camera close and don't need real fast critical focus it is great and expressive and all that. For covering "live" stuff... unless you're shooting a few cameras you're going to miss stuff with a big sensor camera.

I don't do too much event work but I worked an event with my large sensor camera and it is not enjoyable at all. I had my Nikon 70 - 300 on there for close ups, shooting from on a platform behind the audience. It worked but I really wish I had a decent small sensor ENG style camera with a rocker zoom. I would add that if you're using a lens that is not parfocal you're going to buzz focus. Fortunately we had two other cameras to cut with. Honest if I continue that work, I need a small sensor high quality ENG style camcorder.

I got great B roll during the "networking" portion of the evening but the event portion was not all that much fun.

There's a reason there are both kinds. I'm with Viddovation on this one.

 

[yoclay]

LOts of blah, blah here about the ethics and aesthetics of working with larger sensors. Seems off track to me.
This thread is about this new camera from Sony, not the strengths and shortcomings of the S35 sensor format in general.
Guess this thread has run it's course.

 

[Lenilenapi]

Amen

 

[harddrive]

I just did careful comparisons using charts and calculators, and to get an equivalent depth of field on an S35 sensor to that of a 2/3 sensor, it takes approximately six stops on the aperture.

Tools:
http://www.abelcine.com/fov/
http://www.dofmaster.com/doftable.html

The second link is leading you to the wrong conclusion, and I think I know why. All you can load in for the sensor are just "2/3" and "s35" - and in practice you need to define a system resolution for each. To derive ANY dof readings for a "2/3" sensor" you have to define a circle of confusion figure, and for a digital sensor a good starting point may be the photosite pitch - sensor width divided by horizontal system resolution. Same with s35. So for 2/3", assuming width of 9.6mm and 1920 res horizontal, that gives 0.005mm for pixel pitch, for s35 the figures are (about) 23mm and 1920 - or 0.012mm.

If you then use the dofmaster calculator with CofC figures corresponding to those, and the lens focal lengths you calculated (50mm S35 = 19.3mm 2/3") the answer becomes "less than 3 stops" approximately - which ties in with the "2-3 stops" I said.

Used by simply putting " 2/3" " or "s35" as sensor size, I believe the calculator is using the same CofC figure in each case. Which is then not the "all else equal" case I stressed. It would be valid if the sensor was film in each case, or if we were comparing something like 4k s35 with 1080 2/3" - but we're not. "All else equal" in this context means the same system resolution.

If you want more proof, just look at http://en.wikipedia.org/wiki/Depth_of_field , and in particular the section "Same DOF for both formats". As that says:

In many cases, the DOF is fixed by the requirements of the desired image. For a given DOF and field of view, the required f-number is proportional to the format size.

and

Adjusting the f-number to the camera format is equivalent to maintaining the same absolute aperture diameter; when set to the same absolute aperture diameters, both formats have the same DOF.

And the latter criteria is EXACTLY what I described with "Optically, if you adjust iris, zoom and focus with a B4 lens on a 2/3" camera, then put it on an s35 with adaptor without further adjustment, it will behave identically. Same angle of view, same depth of field.

Operationally, you shouldn't be able to tell which is which. "

In this case, the ratio of format sizes is approximately 9.6 (mm for 2/3") to 23 (mm for s35) - or about 1:2.4 (which is where the approx. 2.5 stops comes from). This is also why the focal length changes from 50mm to 20mm for the same angle of view.

Running glass at T16 and T22 is not running it at the optical sweet spot, generally speaking, so if you want 2/3" depth of field, you're better off using a sensor that size, and a lens built for it.

If you're referring to diffraction limiting, then it's true stopping down too much will cause softening. But for a given system resolution what becomes critical is not the f stop but the actual diameter of the iris in mm. It follows that the critical f stop for diffraction softening will be different for a 2/3" system to s35 - again assuming all else equal. Hence if we assume a limit of (say) f11 for 2/3", the equivalent limit for s35 will be around f22-32. This is because in each case the ACTUAL iris size will be the same in mm diameter.

So again, if you adjust iris, zoom and focus with a B4 lens on a 2/3" camera, then put it on an s35 with adaptor without further adjustment, it will behave identically - and that applies to diffraction limits as well. If it starts to limit when set to f11 on the 2/3" camera, it will do the same when SET to f11 on a s35 camera with adaptor. (Because the effect will be to make it a longer focal length and about f22-32 in reality.)

But 2/3" systems tend to use a prism, and have three chips, one for each color. A 35mm single chip bayer sensor is very lossy because any given location can only receive one color type of light. In essence, a 2/3" prism system is going to be 3x more effective at light gathering than a bayer single chip sensor.

Here, in principle, I agree, though practically the difference is going to be more like a single stop. But the point is that a (single chip) s35 camera can have a long range zoom without too much size, weight, performance penalty compared to 2/3". At most it will be about a stop (for 3 chip 2/3") and if compared to something like the single chip HPX600 the relative performances will be identical.

The point as regards this thread is that many people are being put off the idea of long zoom range lenses and s35 for completely spurious and incorrect reasons. You can't just think of f stops in isolation, and it's likewise untrue that large sensor automatically means shallow depth of field.

 

[cuervo]

The second link is leading you to the wrong conclusion, and I think I know why. All you can load in for the sensor are just "2/3" and "s35" - and in practice you need to define a system resolution for each. To derive ANY dof readings for a "2/3" sensor" you have to define a circle of confusion figure, and for a digital sensor a good starting point may be the photosite pitch - sensor width divided by horizontal system resolution. Same with s35. So for 2/3", assuming width of 9.6mm and 1920 res horizontal, that gives 0.005mm for pixel pitch, for s35 the figures are (about) 23mm and 1920 - or 0.012mm.

If you then use the dofmaster calculator with CofC figures corresponding to those, and the lens focal lengths you calculated (50mm S35 = 19.3mm 2/3") the answer becomes "less than 3 stops" approximately - which ties in with the "2-3 stops" I said.

Used by simply putting " 2/3" " or "s35" as sensor size, I believe the calculator is using the same CofC figure in each case. Which is then not the "all else equal" case I stressed. It would be valid if the sensor was film in each case, or if we were comparing something like 4k s35 with 1080 2/3" - but we're not. "All else equal" in this context means the same system resolution.

If you want more proof, just look at http://en.wikipedia.org/wiki/Depth_of_field , and in particular the section "Same DOF for both formats". As that says:



And the latter criteria is EXACTLY what I described with "Optically, if you adjust iris, zoom and focus with a B4 lens on a 2/3" camera, then put it on an s35 with adaptor without further adjustment, it will behave identically. Same angle of view, same depth of field.

Operationally, you shouldn't be able to tell which is which. "

In this case, the ratio of format sizes is approximately 9.6 (mm for 2/3") to 23 (mm for s35) - or about 1:2.4 (which is where the approx. 2.5 stops comes from). This is also why the focal length changes from 50mm to 20mm for the same angle of view.



If you're referring to diffraction limiting, then it's true stopping down too much will cause softening. But for a given system resolution what becomes critical is not the f stop but the actual diameter of the iris in mm. It follows that the critical f stop for diffraction softening will be different for a 2/3" system to s35 - again assuming all else equal. Hence if we assume a limit of (say) f11 for 2/3", the equivalent limit for s35 will be around f22-32. This is because in each case the ACTUAL iris size will be the same in mm diameter.

So again, if you adjust iris, zoom and focus with a B4 lens on a 2/3" camera, then put it on an s35 with adaptor without further adjustment, it will behave identically - and that applies to diffraction limits as well. If it starts to limit when set to f11 on the 2/3" camera, it will do the same when SET to f11 on a s35 camera with adaptor. (Because the effect will be to make it a longer focal length and about f22-32 in reality.)


Here, in principle, I agree, though practically the difference is going to be more like a single stop. But the point is that a (single chip) s35 camera can have a long range zoom without too much size, weight, performance penalty compared to 2/3". At most it will be about a stop (for 3 chip 2/3") and if compared to something like the single chip HPX600 the relative performances will be identical.

The point as regards this thread is that many people are being put off the idea of long zoom range lenses and s35 for completely spurious and incorrect reasons. You can't just think of f stops in isolation, and it's likewise untrue that large sensor automatically means shallow depth of field.

:beer:

 

[Viddovation]

Used by simply putting " 2/3" " or "s35" as sensor size, I believe the calculator is using the same CofC figure in each case. Which is then not the "all else equal" case I stressed. It would be valid if the sensor was film in each case, or if we were comparing something like 4k s35 with 1080 2/3" - but we're not. "All else equal" in this context means the same system resolution.

In practice, we are comparing 2/3" 1080p against 4kS35, since there are virtually no 4k 2/3" cameras in use anywhere, much less ENG news, where we were specifically discussing adoption of 4k S35 cameras like the F5 and FS7 by ENG news shooters. Therefore, I think my point stands.

 

[harddrive]

In practice, we are comparing 2/3" 1080p against 4kS35, since there are virtually no 4k 2/3" cameras in use anywhere, much less ENG news, where we were specifically discussing adoption of 4k S35 cameras like the F5 and FS7 by ENG news shooters. Therefore, I think my point stands.

But cameras like the F5 and the FS7 are as capable of doing 1080p as they are of doing 4k. They don't HAVE to be used in 4k mode, and I suspect currently a good many F5's are being used in 1080p mode most of the time! (Probably the majority!) And when switched to that mode, photosite summation will mean that all the remarks in my previous post (about dof, sensitivity) will hold good. Optically, you won't be able to tell whether a given B4 lens is on a 2/3" camera or s35 via adaptor.

I find it easy to think of any individual shooter using such as an F5/FS7 with B4 lens and adaptor for news work one day at 1080 format, then the following day using the same camera in 4k mode - either with same lens, or fast primes, or short range zooms specifically for s35.

Point is that such an approach gives a lot more flexibility. Doing news? Leave the B4/adaptor on most of the time - but you may have a couple of fixed primes for the occasional shallow dof interview. The only disadvantage in theory is the loss of about a stop due to the single chip effect.

Far too many people are dismissing the large format for such as news because of a misunderstanding, thinking that a long range zoom for s35 MUST be either hopelessly big, expensive etc OR hopelessly compromised for low light ability. That's simply not true for all the reasons above. It's come about because of thinking about a single factor (f stop) without taking into account all the other variables, and similar goes for dof arguments - large sensor does not have to mean shallow dof, it just gives the option of it if a fast lens is used.

 

[Viddovation]

But cameras like the F5 and the FS7 are as capable of doing 1080p as they are of doing 4k. They don't HAVE to be used in 4k mode, and I suspect currently a good many F5's are being used in 1080p mode most of the time! (Probably the majority!) And when switched to that mode, photosite summation will mean that all the remarks in my previous post (about dof, sensitivity) will hold good. Optically, you won't be able to tell whether a given B4 lens is on a 2/3" camera or s35 via adaptor.

I find it easy to think of any individual shooter using such as an F5/FS7 with B4 lens and adaptor for news work one day at 1080 format, then the following day using the same camera in 4k mode - either with same lens, or fast primes, or short range zooms specifically for s35.

Point is that such an approach gives a lot more flexibility. Doing news? Leave the B4/adaptor on most of the time - but you may have a couple of fixed primes for the occasional shallow dof interview. The only disadvantage in theory is the loss of about a stop due to the single chip effect.

Far too many people are dismissing the large format for such as news because of a misunderstanding, thinking that a long range zoom for s35 MUST be either hopelessly big, expensive etc OR hopelessly compromised for low light ability. That's simply not true for all the reasons above. It's come about because of thinking about a single factor (f stop) without taking into account all the other variables, and similar goes for dof arguments - large sensor does not have to mean shallow dof, it just gives the option of it if a fast lens is used.

The day I see news stations do this with the general photo pool is the day when the lead story is flying pigs.

 

[harddrive]

The day I see news stations do this with the general photo pool is the day when the lead story is flying pigs.

Maybe, maybe not - I'm thinking more of a single operator doing mixed freelancing and only needing the one camera.

In which case, it's possible with an s35 chipped camera and adaptor with a slight compromise to mimic 2/3" performance, but a 2/3" camera is a 2/3" camera - period. And whilst I don't see 4k for news any time soon, a 4k capable camera makes a good 1080p camera - a 1080p only camera can't do 4k.

Regardless, real point is it's technically possible, contrary to many of the misunderstandings that widely exist. Large format doesn't automatically mean shallow of field - just stop down 2-3 stops. Large format doesn't automatically mean huge lenses for big zoom ranges, or massively compromised low light ability.