SD LENS "Canon YJ13x6B IRS" or HD LENS "Canon KH20x6.4 KRS"

[Emanuel Altenburger]

Hello guys,

I´m just about to invest in XDCAM HD equipment and have a final question. I´ve read several threads on this forum about choice of lenses but as the opinions are so different I wanted to make a last double check with you. I thought of buying the F350 with the KH20 lens. Then I saw that the SD lens "Canon YJ13x6B IRS 2/3inch Professional Wide-Angle TV Lens" was more or less the same price, is wide angle and has a built in extender. I know that I would have to buy the 2/3" adapter when choosing this lens.

But what is your general experience? Are the HD lenses, especially the KH20 really worth their money or would it be more sensible to buy an SD lens with 2/3" for the same price?

Thanks for your help,
Emanuel

[Alister Chapman]

It is my opinion that 2/3 inch SD lenses are not a good option for XDCAM HD camcorders. I tried a Fujinon 17x7.8 Aspheric (a top end Broadcast lens, not a cheap "pro" lens) on my F350 and it was considerably softer than the Canon Yh19x6.7 1/2 inch SD lens. This is probably down to the fact that 2/3 inch lenses are designed to work with larger photo sites (pixels) than the pixels on 1/2 inch CCD's. My Fujinon lens was pin sharp on my DSR570, but was soft on the F350 even in SD. You also need to take into account that the light paths through the optical blocks are different between 2/3 and 1/2 inch cameras and this can lead to increased CA. Also remember the 1.34x multiplication factor.

The KH20 would almost certainly out-perform the 2/3" lens, it is designed for the camera, the 2/3" lens is not. If you are still un-sure you may be better off seeking out a decent used half inch SD lens, this too would probably out-perform the 2/3 lens at it is designed to work with the smaller pixels of a 1/2" camera.

[Emanuel Altenburger]

Hi Alister,

thanks a lot for your reply.

Best regards,
Emanuel

[Jonathan Ames]

Ultimately, the choice is yours but if you're going for HD, it should be HD all the way. The glass is 90% of the image you acquire which is one of the ways we make the 350s perform in an HD Network series the way we do. We simply can't get the shots we get with an SD lens irrespective of the quality of the SD lens because the configuration and standards are completely different. I've said it before as recently as in an interview for Telemundo yesterday afternoon; yes, Sony is one of our sponsors as is Fujinon but when it's all said and done, the camera
s just a box. Granted, it's one of the best boxes we've ever sen which is why we're using it for the new serties but it's a box. The Fujinon HD lens we select to use WITH the 350 is what makes the magic; that and lighting. We shot a candle sequense for the interview to show the capabilities of the camera and the glass and at 6' in a totlly black room with the candle light the only source available, you could see clearly not only the broad-stitch weaving in the blackened wick inside the base of the flame but the individual threads in each of the stitches. You simply can't dop that with SD glass. So, with all due respect, we don't do anytyhing you can't do so if you're going the extra mile for one of the best HD cameras out there today irrespective of price, buy a utilitarian ENG lens in HD configuration for your everyday shooting and study and learn the characteristics of glass and cinematography in general and then rent the right HD lens for your specific aplications. If you already own the HD 350, you're 75% of the way there. Rent the other 25% and shoot what your camera's capable of.

[Alister Chapman]

Originally Posted by Jonathan Ames

We simply can't get the shots we get with an SD lens irrespective of the quality of the SD lens because the configuration and standards are completely different.

In most cases you can get get SD lenses that have the same focal length, designed for the same size imager as the currently limited range of HD lenses.

I am not trying to say that there isn't a difference between HD and SD lenses because there is. BUT my experience and the experience of many other that have actually done comparisons is that the difference is small and often in practice hard to spot.

Using 2/3" lenses, SD or HD on cameras with 1/2" CCD's is a compromise at best, they are quite simply not designed to work with the smaller pixel size and shorter light paths. My tests have shown that a 2/3" HD lens on a F350 performs no better than a decent 1/2" SD lens, so it's not quite as clear cut as simply saying you must use an HD lens.

In my opinion, having done many tests and comparisons since getting my F350 in May, first and foremost get a lens designed for 1/2" optics, preferably a HD lens.

[Jonathan Ames]

We all have our opinions and, a someone once said, you don't have to be disagreeable to disagree. So with that and truly all due respect, I have to disagree. As most know, we're shooting a primetime feature pilot for dual release this spring in dual languages; a daunting task at best. It's budget tripled which, because it's television is small by today's standards but significant at 7 figures nonetheless and, with 23 years in this business and the pick of the litter in cameras and lenses, I selected the 1/2" F-350 together with Fujinon glass. Why? Because, quite simply, I didn't need the horsepower of an F-950 for the script which was available as well. The 350 fulfilled every frame of every need I had for the picture. I tried the SD lenses and, when you're talking 1/3" cameras, I agree; the difference between SD and HD glass isn't that noticable. And, if you subscribe to the "it's only a 1/2" camera" mantra, then I'd agree with your thought process. But the fact of the matter is that the F-350 isn't your average non-2/3" camera. Again, not to belabour the point, but I too have come from a film background and now video for the past 8 years and I make sure I surround myself with the best in the business before making a decision. After all, 4, 6, 8 or 10 eyes are better than two especially with people like George Spiro Dibie and Rodney Charters available to me when I'm considering what I'm going to shoot a particular project with and the botom line is that the F-350's technology has broken the barrier that used to separate the "other" cameras from the 2/3" cameras. And that means you can't get the performance out of an SD lens that you can from a 2/3" HD lens when it's in front of the F-350. And then there's the latitude issue. The F-350 is designed, unlike the any other 1/2" camera, with a significantly wide latitude when the scene is lit and set correctly. So not only are they not as sharp as HD lenses, they do not "see" into the shadows as well and so shadow detail is lost with SD glass. Dark blues fall into blacks and this was well-proven in the opening shot of El Papel where the apartment is completely dark save for 4 1X1 LitePanels with full CTBs and strategically placed candles. The LitePanels were simulating nighttime moon light coming in through a window behind the character and the candle was lighting his front. (Think Laszlo Kovacs in "Reflections" p. 141 only darker). With a 1/2" camera we were able not only to get the exact shot I wanted, you coulod count the stitches on the actor's dark grey sweatshirt as his dark, Mexican/American hair fell, strand-by-strand, into the background blackness with diminishing lux via the candle light from the front and the blue-gel hair light behind. Had the camera and the HD lens not ben able to get this shot, since one of the benefits of HD is to be able to underexpose a little to retain highlight detail, then later lifting up the shadows in the grade, we could have brought the look out in post. With the 350 and the HD lens, we didn't have to. You simply can't do that with SD glass. I know. I tried the opening shot with a series of both HD and SD lenses and settled on the 8, 12, 20 and 40 HD Primes, the 15X7.8 HD CineZoom and the venerable 10X100 T1.8 HD Lucas Lens. This is why I say, as a practical matter, using standard def lenses is not a good idea at all when you're going for your best and the F350 makes going for your best much easier given its performance v. price point. Then there's the aberrations on the edges that appear in SD lenses but not in HD glass. The tolerances and precision are simply too close and too high.

There is no argument that 2/3" is better than 1/2" but in my humble opinion, and I truly mean that, to hold to that thought process would have us still shooting film instead of video. But the fact of the matter is that the Panavision and Fuji Super HD lenses are superb. They are fast at T1.6 and designed to integrate seamlessly into a 35mm method of operation and, with adapters, the 2/3" and 1/2" video as well. However this too comes at a cost of size and weight when compared to other lenses. To create a fast zoom lens for a 2/3 or 1/2" image plane, the front element has to be large. Generally speaking the larger the front element, the less depth of field. The 2/3 inch image size of HD is less than half that of 35mm motion picture film. As a result a wider lens is required on HD to match a given angle of view on 35mm. Wider lenses have greater depth of field, this greater depth of field is both a help and a hindrance. Great for low light work. Not so good for controlling the sharpness of backgrounds in other situations and that's where knowledge of lighting and cinematography comes in. In other shots in El papel, candles glow 2-3 feet behind the characters. Because of correct lens choice and settings, T-stop and lighting, we were able to obscure the candles' flames while keeping the actors' faces in crisp, clean, clear focus. Depth of field for a given angle of view at T4 on 35mm compares to T1.6 on 2/3 inch chip. In fact, we shot the vast majority of the interior, dark scenes wide open at 1.6. So, in the end, with a camera as capable as the F350 is and has proven to be (otherwise we'd be shooting this pilot on film or, at the very least, 2/3") applying the multiplier of 1.37 together with 1/2" to 2/3" adapter if you know your craft there's virtually nothing that anyone can do with a 2/3" that we can't do with the F-350...and I say virtually because there are of course significant differences but none, in my again humble opinion, to say that a 2/3" HD lens on a F350 performs no better than a decent 1/2" SD lens. If it was, we wouldn't have selected the Sony and Fujinon, we wouldn't have started shooting the English pilot and been asked to shoot is also in Spanish for Telemundo distribution based solely on the dailies the network saw and we'd be saving a heck of alot of money. I don't like spending money. I hate spending money and there's a big difference between HD and SD glass. I like coming in under budget or at least at budget. So, again, respectfuly, find me a lens that, at 6' can show not only the weave of the candle wick in a completely dark apartment save for the candle flame itself but the fibers in that strand and, as I've been known to do, I'll happily concede.

Like yours, my reputation on this board for honesty and integrity has been proven time after time. We contribute here not for our own misguided egos but to lend whatever experience we have to others in the hopes that their work product will be better because of it. Since a picture's worth a thousand words, I just asked Paolo, the feature's lead editor, to cut out a 5 second, clip that shows not only the flame but the ridges in the boy's finger next to theflame and a fleck of lint on the edge of the candle. Now even at web resolution on a small monitor that's probably far from properly calibrated, you can see everything. While I don't have the same shot with an SD lens, when I was choosing the glass for the feature pilot, I started with SD lenses knowing what I wanted my establishing shot to be. These were top-of-the-line SD lenses. And from there I progressed through them to the HD series and finally, for this opening shot, Fujinon's 10X100 which they had to find and fly in from Germany for us. Believe me, if I could use a less costly alternative to anything, I'm there. Glass just isn't the place to cut corners. Not only is there a difference between HD and SD glass at all film plane sizes, there's a marked difference. And since there's only one thing less forgiving than High Definition work, and that's your audience, with coomplete respect to your opinion, I have to disagree. But this argument will go on forever and as someone else once said, "Beauty is in the eye of the beholder". For me, I see the difference with complete clarity. For Alister and Nate Weaver and others, it's minimal at best. I guess you just have to rent both a great SD and HD lens appropriate for the shot you're going for and make your own decision. If the difference isn't there for you, maybe you can get away with it.

It's 6:07 pm PST and the upload will be completed in 15 minutes for the 30-some Meg compressed file of the candle. Find it at http://www.paolociccone.com/videos/Candle-H.mov

OK, it's there now. And I have to add a caveat. I want the readers to understand that just because we disagree doesn't mean anything other than we have differing opinions. I have the utmost respect for my friend Alister across the pond whom I've never met but hopefully will in June when I'm in London for a week with George and Nate whom I've had the pleasure of meeting once at JVC when he came up and introduced himself to me. I haven't seen Alister's work but Nate's is wonderful and his dedeication to his craft and especially this forum is second to none so to those of you who read our posts, know that there's no malice afore thought, simply differences of informed experience which we gladly pass on to all of you via Chris Hurd's hard work. I hope those of you who find your way to NAB in March find your way to Sony to find me and elsewhere to find Nate. We'd be pleased to meet you and discuss our shared passions with you.

[Jonathan Ames]

I found a great article that explains the difference between SD and HD lenses and why it occurs. It's a bit technical but after a couple of readings and some more research, I got it which means it can't be that dificult. I hope it helps the readers.

http://broadcastengineering.com/hdtv...lens_design_4/

[Alister Chapman]

First off I agree with everything Jonathan says about FOV, DOF and that HD lenses should be better than SD.

BUT the point that's being missed is that 2/3" lenses are not designed to be used on 1/2" CCDs and there are serious problems in doing so.

As we all know, when light is passed through a glass lens it get bent. The aim of a good lens is to focus light into a single point, in a single plane. The problem is that differnt colours of light bend by different amounts. Lens manufacturers use all sorts of combinations of different glass and coatings to minimise this, but it is all but impossible to get the focal lengths for the red, green and blue parts of the spectrum the same. This is compounded by the fact that once the light leaves the lens it then, in the case of a 3 CCD camera has to pass first through air, then a glass filter, then air, then through a complex optical block that splits the light into R, G and B channels, all this introducing further errors.
Here's the rub, 2/3" lenses are designed to work with the amount of glass in 2/3" CCD blocks. A 1/2" block only has half the amount of glass, as a result when using a 2/3" lens on a 1/2" block a small registration error between the R,G and B channels is introduced. Film cameras and single chip cameras don't have this problem. Indeed much of the processing done in a modern 3 chip camera is there to reduce all the problems that are created in the optical block. So to start off with, using a 2/3" lens on a 1/2" block will lead to a small registration error, and thus apparent softening of the image.

The other issue is that the resolution of a 2/3" lens is not optimized for the much smaller pixels on a half inch CCD.

Lets see if I can explain this. I have not been able to get the correct figures, so I have made some up to illustrate my point. The actual numbers are incorrect but the orders of magnitude are somewhere close.

A 2/3" HD CCD requires a resolution on the chip of 100 lp/mm
A 1/2" HD CCD requires a resolution on the chip of 150 lp/mm

The above statement is pretty obvious, smaller pixels on a smaller chip requires higher resolution per square mm.

But what about SD?
A 2/3" SD CCD requires 50 lp/mm
A 1/2" SD CCD requires 75 lp/mm

Again I would suggest that this makes sense. There are fewer pixels per square mm so the overall lp/mm is lower. But again smaller pixels on a smaller chip requires higher resolution per square mm.

So lets consider what happens when you put a 2/3" lens with a design resolution of 100 lp/mm on a 1/2" CCD. The answer is that the lens will not appear as sharp as it does on a 2/3" CCD because there is a resolution shortfall of 50 lp/mm. It's even worse if you put a 2/3" SD lens on a 1/2" HD camera, theres a shortfall of 100 lp/mm at HD and a shortfall of 25 lp/mm on SD!

Take note though of the relatively small difference between the 2/3" HD and 1/2" SD lens, a difference of only 25 lp/mm! Add to that the registration error in with the 2/3" lens and I hope you can see why I don't believe the difference between a 2/3" HD lens and a 1/2" SD lens on a 1/2" camera is very big.

This a theory and yes there is a lot more to this than resolution, but my tests have born this out in practice.

Unfortunately there seems to be great variability in the quality of the current ranges of 1/2" HD lenses and the range is somewhat limited otherwise the answer would be simple... 1/2" HD glass on 1/2" HD cameras.

[Jonathan Ames]

Two of the great things about this and other boards is the caliber of individuals and the depth of knowledge that exists within its members. Not coming from an engineering background but from a finance and motion picture background, I can't hope to know that which Alister does relative to the physics of light. But, as Beau Hooker (no, I'm not kiding, that's his real name) said about pornography; "I can't define it, but I know it when I see it." To get the best results, I use the best equipment I can find be it glass, camera, filters, support or most of all, people. For El Papel, I settled on what I believe to be the best glass on the market for what I consider to be the best camera on the market for our current production; Fujinon HD on the F-350. Again, beauty is always in the eye of the beholder so irrespective of which lens you choose, I think Alister would join me in recommending that you use a quality monitor like the HD Panasonic 2600 properly set up to view images in an environment as close to the environment in which you'll be shooting as possible and then select the tools which provide images as close to your vision as possible. This is not a job; it is a passion. In my case it's a passion that I care for so much that I spend an inordnate amount of time and money passing along what I've learned in more than 2 decades of practice and the most notable thing I've learned is that it is the individual artist that defines the art. For Alister, the difference isn't there. For me, it is. That's how art is. That's how artists are. I could go on and on discussing art history where artists despised eachother and publicly denounced each other's ideas and work as so much rubbish only to find, centuries later, that these pieces of "rubbish" live on centuries later in museums throughlout the world admired by millions who, in turn, find quality in both. Perhaps that is how it is here. This is a tremedously passionate calling and you are the beneficiary of what Chris Hurd had produced; a forum where artists can discuss their views and you can male your own decision. We wish you good luck and hope that you find the information, from both sides of the fence, beneficial in arriving at your decision.

[Alister Chapman]

Jonathan and I do obviously come from very different backgrounds, I am from an engineering based background and have moved over the past 20 years or so into the more creative side.
If which camera or which lens to use was black and white there would be no need for forums, you would simply use camera A with lens B to achieve shot C in the way director D want's. But this is an art so different people will see things differently, which is good a it leads to the diversity of styles and programs we have today.

I would love to spend some time with you and your team Jonathan and learn about your methods and techniques. Although I'm not quite sure how they would translate to my severe weather filming, which tends to be a case of grab what you can get! Next big shoot is in Denver filming the snow storms.

[Greg Boston]

Originally Posted by Alister Chapman

Next big shoot is in Denver filming the snow storms.

Alister, I can probably save you some money on that. Just leave the white balance card in front of the lens...presto, instant blizzard shot. (grin)

-gb-