primes
 

Anyone think Canon would ever build a set of XL primes? i'm pretty sure they'd be a very hot ticket in the low budget feature world, if they could build say, 20,35,50 and 100mm equivalents with something ultra fast like an f1.2 you could narrow the depth of field to 2/3" levels, not to mention the obvious low light advantages. no matter how many engineers are working on it a 20x lens will never have the level of clarity of a prime, I for one would be willing to spend whatever they asked for something like that.

It's an excellent idea, but I seriously doubt they'd ever do it. Limited demand wouldn't be nearly enough to match R&D costs, tooling up and production etc. Although I'd love it if they proved me wrong.

You're from Pedro? Say hi to Watt for me.

I think we zoom too much in video. With primes, we just have to move the camera more often to get the framing and perspective that we want. Good for a change I would say. A compromise solution would be great too. Like a 20mm, 28mm-105mm and 100mm-400mm. Still photogs carry all that stuff day in and day out, would the video pros go for it? I wouldn't mind. For toting around, I'd just keep the 28mm-105mm zoom on.

it seems like anytime enough people talk about a certain needed product on these boards a solution shows up on the horizon within months. So come on everyone let's campaign for XL primes!

a third party could make them fairly easily i would think, they don't need autofocus and i'd be happy with a mechanical aperture ring, so it's really just scaling them for 1/3" and hd resolution, and to help recoup costs i would think they could have an optional mount for the JVC proHD. no electronics would be necessary, no zooming back focus issues, just super nice, super fast small size glass.

yeah Chris, i ran into Mike about a month ago, he's still playing randomly around here all the time.

Agree with Chris that Canon is really unlikely to develop primes for this camera. I know there are trade-offs, but there are two available solutions: EF adaptor and mini35.

I have to disagree on this one, I think there definetely IS a market for a set of HD XL primes.

Who else is going to spend $9k on a camcorder but professional freelancers, TV, and SERIOUS hardcore posers? who else could Canon be trying to market this camera to? I think there would be a larger market for ultra fast prime lenses than there would be for an uncompressed HD SDI jack and the HVX could never ever touch something like that, I think an option like primes would be the best case to beat out the HVX. or maybe a canon made 35mm eos adapter that lets the camera control aperture (1-1 ratio) that might be a cheaper bet.

I'm with you guys. I've always loved primes for their compactness, speed, weight, lack of flare and lack of distortion.

The 28 to 105 mm that came with my Canon SLR is certainly useful. It's also pretty compact, but oh the distortion. If I'm shooting anything such as a building I have to shoot at 30 mm - any less and it barrel distorts horribly, and any more and the evil pincushion sets in.

So I'd love a flare-free and distortion free 3 mm f/1.4 with a 6 bladed iris and a perfect petal hood. It'd weigh next to nothing and could be kept in your top pocket.

Sigh. I can but dream.

tom.

I think primes would rock but I have to say that for the cost of hd primes you probably could get a few zeiss primes and a P+S adapter, which would give you not only primes but also 35mm d-o-f. Personally I would much rather someone come out with an HD-SDI recorder...

I'll give Cooke Optics a dollar to make some S4HD XL-mount primes... How could they say no for a dollar?

I agree completely! Nothing says "amateur" to me like an unmotivated zoom during a shot. I think of a zoom lens as a variable focal length lens allowing you to precisely frame the shot while holding a desired geometry between the visual elements inside the frame. But once it's framed, action takes place inside the frame and the focal length doesn't usually change during the shot itself. There are exceptions to every rule, of course, but IMHO, the use of the zoom instead of a camera movement, or as a transition between two framings that really should have a cut between them such as going from MS to CU is way too common.

I must say though that I zoom all the time during my weddings and events. It's on the edit that I cut them all out, and if I've zoomed fast enough the faces are still in the same place, and I have excellent continuity.

tom.

I think this is a great idea. With high quality individual elements and some work it could be done. Its a little unlikely that really high quality lens elements are available. Their are places out their to get all the optics to put together a lense but I wonder how good it would be.

Someone posted an optics simulation software a few days ago somewhere. Someone want to start designing?

That's a different thing altogether. Sounds like you are using the zoom appropriately. I was referring to leaving the zoom motion intact in the final edit, so it ends up looking like the lens is a firehose swinging around the scene and using the zoom as a substitute for a dolly in or out..

The basic rule for zooming is to shoot enough head and tail on the shot so you can cut out the zoom part of the zoom.

Primes for small cameras would be very cool. But I doubt it will happen. Lots of design and development work there for a very limited market.

Maybe some C mount or CS mount lens for 1/2" could be adapted and someone make a primes series for the canon mount. I'd be interested in work on it but don't currently own an XL series camera.

To use zoom as a framing device and not calling attention to itself is the right approach I would say. For wedding and event coverage in which there is no second take or you have your camera on a tripod, I would agree that a zoom is invaluable (or even indispensable), both as a framing device and for creating a sense of capturing reality as it happens. But even here I would go for a short range zoom if available. You'll be amazed what such a lens can do for you if you learn how to anticipate your live action a little better. The end result will show your professional intelligence much more convincingly than a whole load of shifty zoom actions. To me, you cannot claim that you use zoom heavily because the action happens to fast and is too hard to predict. Learn how to pick your position, angle and the use of a certain focal length.

People talk about the film look a lot, but part of the mystique of a celluloid feel is having the camera 'contains' the action with just one focal length doing a long take. Whatever action that happens stays inside the frame. That can be done with video too.

As for barrel or pincushion distortions, practically any zoom lens would have a certain degree of that. That's part of the reason why some of us like primes.

a couple of years ago i saw Martin Scorsese speak at the DGA and one of the points he made was that when he was in film school camera movement was difficult so you had to have a good reason to want to do it, but today camera movement is so easy that everyone does it without thinking about it and it's time for us to start thinking about when it is time to keep the camera stationary

-Jon

Problem with C mount is that the back focal distance is much shorter than the XL series. CS is even shorter. So it makes it hard to use with a XL-H1.

Maybe the lense elements can be moved to change the focal plane.

Probably just as easy to start from scratch and design a lense. Wish I had the gear to start experimenting.

I like the primes idea and even more if they could be built them realivitely cheaply. Would allow a nice option for people more into movie making and stuff vs situations where you need a zoom. For people who only make movies then being able to save the money on the zoom when they buy a body kit would definetly be a plus.

Yeah, reworking the optics would be just easier to build them from scratch. C mounts don't work. I'm not sure they could be made cheaply though. If they were cheap, they would most likely no be any good for HD.

Michael your right. If it they did exsist and were "cheap" then probably no good. I should use the term cost effective or really good Value.

Most lenses have so many elements though, that designing a prime lense would take a lot of work without some compromise. So wish I had access to a lense kit for experimenting. Sounds like fun.

don't forget they've got to be ultra fast

a few years back canon had an EF lens that was a 50mm F1.0, i think it sold for around 3 grand and they only made maybe 1500 of them total

I know a 1.0 is pushing it a whole lot but I imagine you could get 35mm depth of field with something that quick, i think a 1.2 is possible and effective enough to be worth it,

again, am i wrong that there would be almost as large of a market for H-1 primes as there would be for an H-1?

i just don't see ppl spending 9 grand to point and shoot their kids birthday for fun and the local tv and indie film guys (like me) would kill for some primes like that and it would really make the H-1 the most interesting "low price" camera, i could see thinking that the market wasn't there for a XL-1s prime kit but the H-1 is going after a completely different level of "prosumer" primes would bury the HVX.

if there isn't a market for primes explain the big hit that mini 35 made, and a set of native primes would be better in many instances, instead of the light loss of a relay lens, and adapter, and a lens, you could have a straight f1.2 to the chips by the time you get to a pl mount lens you've lost so much light that you're in need of more juice and that means a generator, and that means ppl setting up the generator, and that means paying off the neighbors to let you run a generator in front of their house, and running cable and leaving a deposit. as much as possible i like to light with the locations existing electrical but that generally limits you to 1.5k@120v and no matter how many different circuits are in the house once you start gelling down your 1ks you're hurting for light quite quickly with mini35.

Honestly, I would pay good money for a set of XL primes at 24mm,50mm and 85mm w/ 1.8 aperture.

I've been doing a little looking around and their seems to be a lot of different lense designs over the last 100 or more years. The cooke triplet, the zeiss tessar, and more. These aren't brands (they are but not what i'm talking about) these are types of lense arrangements. I wish I could disassemble a prime lense to see whats in them. I'm thinking two lenses . A diverging one to get the backplane right and a converging one for gathering light. And of course a method to control the aperature.

I don't have enough optics understanding to figure out everything so I'm thinking out loud. I'm never going to be able to build one for a few months but I'm so interested now. Darn current projects that interfere with new project ideas.

Tony, I'm assuming you mean prime equivalents for a 1/3" sensor that would give the same FOV as the 24, 50, 85mm on a 35mm film camera. Correct?

Over the years a lot of the still photography lens makers have included cutaway artists renderings of the construction of their lenses. Even in a single focal length lens, there's a lot more than 2 elements. More like 7 or 8:

http://www.mir.com.my/rb/photography...ernalillus.jpg

I think there is a possibility that you're right and that people would buy primes, but I disagree with the reasoning and the extent. I mean come on, the guy shooting his kids birthday party doesn't care about prime lenses, if anything he wants a zoom. Can you imagine his dismay at losing all of that "great" footage because he were too busy changing lenses? A TV station isn't going to want primes because if it's live, they're going to need to be able to change the length of the lens quickly, and you don't get that with primes, at least not compared to zooms.

So the only place that leaves a market for primes is the indie movie market. Let's talk about HD glass now, a set of zeiss digiprimes (for b4 mount cameras) is roughly 20k a piece, fuji and canon both have some as well and they come in slightly cheaper. Now I realize this is a "prosumer" format camera but it has a smaller imager so the glass is going to need to be at least pretty close to the same quality. but let's say they can make it for half price, heck let's say they can make them for a quarter of the price, is everyone going to go out there and spend $3500-5000 on a single prime lens if there were only 3 that you wanted, say 24mm, 35mm and 50mm you're still looking at the cost of the camera. For what? 3 prime lenses that still don't give you 35mm depth of field. Which I believe is the reason that the mini 35 took off technically you can put zoom lenses on that as well so it's not a prime only thing it's a 35mm plane thing.

I think to be honest unless they can get REALLY good quality optics for 1/10th the price of "professional" HD primes, there's really not a market for it. But hey that's just my opinion. Personally I would love to get a lensless xl-h1 and a mini 35 with some superspeeds but that doesn't meed they should sell that as a package too...though they should ;)

It would help if Canon didn't insist on their own 1/3" mount, and used the standard 1/3" bayonet mount (same the HD100 uses). Then as the market would be larger, the possibilities for somebody releasing a prime set for this mount would be bigger. Much like B4 is the standard for 2/3".

Good point michael, I suppose if there was some sort of standard mount then a company like century may have motivation to create a set of primes knowing that the potential market would be larger.

Haven't seen the two mounts side by side but wonder about the possibility of building an adapter. Have a feeling it would put the focus plane out a litte. Thoughts.

I do know their are more elements that the 2 I described in most commercial lenses but since I'm only talking theory and at the simpliest idea stage now that I'm starting with the simple problems and then will think about the others later. I'm thinking that for every lense added their is more light loss. Some of these lenses are doublets for reducing chromatic abberation and other distortion.

I'm onboard with Nick H. on this one.

For the realistic price of a set of 1/3" primes you could buy into a 2/3" camera...

I still think there's a bigger market for 1/3" primes than there for new 16mm buyers, but how many companies build 16mm lenses? but i don't know very many people that own 16mm and certainly not that are in the market to buy brand new (i still have a worked over arri-s non sync but haven't used it in over a year and a half) that said, someone could find a fairly nice used 16mm package for the price of an H1

Canon had a Super-8 camera (the 310XL) that had a 3x zoom with an aperture of f/1.0. I have one of these and can confirm that the f/1.0 aperture was constant throughout the zoom range. Of course the Super-8 image area - at 4.1 x 5.7 mm - is the same size as a half inch camcorder chip, so making such a fast zoom for 1/3" chipped camcorders should be easy.

tom.

I thought super 8 was closer to 1/3" than to 1/2".

1/3" chips measure 4.4 mm x 3.3 mm for their effective area, considerably smaller than the Super-8 frame.

And why it should be easy? A lot of threads recently talked about the fact that it is more a challenge to make a good lens for a smaller chip than a bigger one. since the chip is smaller, the lens must resolve more pixel with a small area of glass.

Close enough. Closer to 1/3" than to 1/2".

One thing to keep in mind is that these cameras typically use 3 sensors with the light divided via prisms and coatings. The prisms have a limiting f number (typically around f1.6) that means no matter how fast a lens one used the the image reaching the sensor will not be faster than the limiting value -- so an f 1.0 lens is no faster than an f 1.6 zoom.

Also the small target size allows the design of zooms whose performance rivals the best primes-- it is unlikely one would see a significant improvement in image quality over a well designed and manufactured zoom.

The one caveat is that the zooms for these small (1/3" ) camcorders typically "ramp" aperature (slow down) as you approach the tele end- to f2.8 or more. But the depth of field is a problem at the wide end not the tele for the most part.

Interesting post Bill - I'd not thought that the beam splitting prisms would limit the maximum aperture value.

You say:
But the depth of field is a problem at the wide end not the tele for the most part.

but do you mean depth of focus rather than field?

tom.

Tom:

I meant depth of field but may not have been clear why. In reading thru this thread, as well as many others, it seems there is a very strong desire to acheive a shallow depth of field for the purpose of isolating the object in the frame that one desires to focus the viewers attention on.

The tremendous depth of field present in these small camcorders (compared to 35mm Cine formats, or even 2/3" video) at the shorter focal lengths required to achieve comparable fields of view, seems to be one of the motivating factors in the expressed desire in this thread for fast primes for cameras like the Canon H1 or the JVC 100 HDV cameras that do allow for interchangeable lenses.

It was my expressed opinion that the fact that the zoom lens might be only f 2.8 at the tele-end, as opposed to f 1.6 at the wide was not a significant problem in the quest for the "shallow depth of field" look.

And yes the prisms limit the f number. The prisms also create abberations and other problems unless the lens is specifically designed for the type and thickness of glass used in the prism system. Because these issues are most evident at short focal lengths and high apertures, they tend to be less noticeable when using 35mm SLR lenses on a camera as the focal lengths are relatively long in video terms.

In most cases the zoom lenses designed for the camera have an aperture very close to the maximum the prism design will allow, at least at the wide angle end.