HD lenses a scam?

magichristopher

magichristopher

Well-known member
I am a little confused here and I am wondering if HD lenses are even that much better than their SD counterparts to warrant such a steep price difference. It just seems a little bit like HD lenses are more about marketing, than resolving more lines. I have a crappy four megapixel camera and it has a small cheap lens, but can take remarkeably sharp detailed pictures, at twice the resolution of HD. Also the quality of pics that Reel Stream is doing with their mods for the DVX and getting near hd quality from the stock lens is amazing. I am sure that the Leica Dolomar lens on the DVX has even more resolving power but the CCD's aren't able to squeeze out any more pixels. So how much better are HD lenses?

I know that there are many variations of lenses, and they get considerably more expensive when the CCD size goes up, but how much more money really goes in to developing HD lenses when compared to SD? Is it possible that for sub $10,000 dollar market of hd-hdv camcorders, that the lenses just go through another step of quality checking before they can be put on a hd camcorder?

I just dont understand why HD lenses are so superior for less than 10k on a camcorder. The thing that really got me wondering about this is the new canon xl-h1 and I pondered that they might be using a nearly identical lens that the XL2 uses with slight modifications and better quality control.
 
The considerable difference in the cost of an HD vs SD lens is likely driven partially by economy of scale. Think about how many $300 digital still cameras get sold in a single holiday season? That number likely exceeds the entire production run for a camera like the DVX for its entire manufacturing life time by a decent factor.

Another issue is the size of the elements. The probability of a manufacturing defect increases exponentially with the area and at some size becomes more of a probability than a possibility. Also the amortized development costs are likely greater for a HD lens and these costs are distributed over fewer number of items being sold. All these factors add up to higher costs.

If these seem expensive to you, then just look at what a box of 35mm anamorphic primes are worth. It so much that hardly anyone owns them, rather they are rented to productions as required. I rented these on a few occasions and you can quickly have a small flight case that has a value similar to what a decent home costs. Makes things like the XL1/2, DVX and HVX seem like a downright bargin.
 
The JVC HD100 has an "HD" lens, but one with an approximate valuation of $800. Compared with the optional HD lens which lists for $11,995. What does a cheaper "HD" lens get you? Lots of chromatic aberration, at least. The lens is surprisingly sharp, but you can see some examples of chromatic aberration at http://www.icexpo.com/HD100/index.html. There were also some pictures posted at CreativeCow by a guy named Matt which had some examples that were as bad or worse as the examples on the page I listed.

A great-quality HD lens will not be cheap. A cheap HD lens will not be great quality.
 
wow.. after viewing those samples all i can say is that hopefully the cost savings from having a non removeable lense in the HVX affords it a much higher quality HD lense than that of the stock HD100. removeable or not I just want high quality ..if its high quality to begin with i certainly wont feel the need to pull it off and spend 12,000 to replace it with something that is.
 
Hopefully, the HDX lens will be decent? I see many possibilities for this cam with something like the G35 and the use of other quality lenses.
 
I am just curious about the link to the pic with chromatic aberation, Barry. I know this has nothing to do with the hvx, but when the hd100 is in SD is the chromatic aberation less? Does the HDV mode bring this fault out more so?
 
What I really don't understand, I guess, is why can the guys at reel-stream be pulling out images that are nearly HD from the "SD" lens of the DVX and why can my crappy digital camcorder get clean detailed prints all the way to 4.0MP, when it cost less than probably $25 dollars to make. (I do realize that my digital camera has a small sensor, and there is a significant difference between cmos and ccd)


I am sure that if the DVX would allow for more resolution that the lens would be able to resolve this extra rez, so really how much better are HD lenses for the prosumer camcorder market. What are the biggest differences that warrant such a steep price
increase? Is it just quality control measures or marketing?
 
MatthewRyanMCK said:
but when the hd100 is in SD is the chromatic aberation less? Does the HDV mode bring this fault out more so?
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I think that's a great question, and I don't know the answer to it. I haven't used an HD100 in DV mode or SD mode yet.
 
magichristopher said:
is why can the guys at reel-stream be pulling out images that are nearly HD from the "SD" lens of the DVX
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Well, I guess the question is: ARE they pulling HD images from the SD lens? It's my understanding (which is quite limited when it comes to the Andromeda, by the way) that they are not pulling out HD images; they are pulling out the native CCD resolution. The HD image is created by a sampling algorithm in the computer after the fact. But the chips are standard-def, and the lens is resolving a standard-def image onto the chips.

so really how much better are HD lenses for the prosumer camcorder market.
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The ones I've seen so far range from mediocre to awful.

What are the biggest differences that warrant such a steep price
increase? Is it just quality control measures or marketing?
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I'm sure Bill Turner of Century Optics could answer in depth. As an allegory, what is it that makes a BMW cost so much more than a Hyundai? The HD lens has to be engineered to deliver around 3x as much optical resolution as a standard-def lens. That means better glass, better design, tighter tolerances, more precision manufacturing techniques, all that sort of stuff. And it has little to do with prosumer cameras -- look at interchangeable lenses for 2/3" cameras. You'll see standard-def lenses for $7000 and the cheapest high-def lens is around $25000.
 
Generally a lens costs more with the square of the radius, so a small lens is very much cheaper than a big piece of glass. Digicam lenses tend to be very small, and show significant chromatic aberation, and tend not to have the zoom range of a decent video lens.

HD lenses for 2/3" chip cameras need to be about 2.7 times as sharp as a top end SD lens, and hence for a 1/3" chip camera, about 5.4 times as sharp.

Now try and optimises for lack of chromatic aberation, size (bigger glass lets more light in) and resolution, and zoom range, and that's why a decent HD lens costs so much. That, and as has been pointed out, they're not mass produced items.

Thanks Barry for posting the link to the HD100 images. They're shockingly bad. Now, who do I remember predicted it would be so..... My memory escapes me....

Graeme
 
And if the HVX turns out to have similar chromatic aberration problems with its fixed lens it will further prove your previous posts Graeme and Barry - that HD lenses are costly to make and we should not expect a $25k equivalent lens on a $6k camcorder. The difference being, on the HD100 and H1 the user has the option to remove the lens and put "real glass" on the front. If the HVX lens has CA problems, there isn't that option. DVCProHD compression is obviously superior to HDV, but if you have a sub-HD standard lens feeding images to the HVX, we could just end up with chromatic-aberrated, 4:2:2, intraframe images. If the MTF chart for the HVX lens shows it to be below the range to adequately resolve HD images, users will have no recourse to correct the problem.

Barry's posts, and those of others that experienced CA problems with the HD100 16x, uniformly stated that they experienced those problems at the high end of the zoom range, where CA problems will usually show themselves. There have been some excellent posted images from the rest of the zoom range of the lens, and shooting other subject matter than backlit wine glasses. No MTF charting of the 16x lens has been done, but it appears that the lens does a reasonably good job of resolving HD images through its zoom range until the CA problems at long focal lengths.

I'll look for you guys to be just as vocal if the HVX lens turns out to have the same CA problems. And if it does, I'll be interested to see what your workarounds and solutions are...

Gibby
www.cut4.tv
 
You're right that I'll be critical of the HVX200 if it also shows a bad image. A bad image is a bad image no matter which camera makes it :)

Indeed, with the HD100 you can replace the lens, but at that point, with the price of the lens, you may as well replace the camera as well to keep the camera in line with the price of the lens.

Interesting times ahead, as by the end of the year, we'll have basically 4 different cameras to choose from.

Graeme
 
Someone really needs to make a camera that has a 35mm (or heck even APS size) sensor so you can use cheap and plentiful 35mm still lenses on a video camera. I'm kind of surprised that Canon hasn't already done this. I think I would be pretty happy shooting with my Canon EOS glass. I imagine the problem is producing the sensor :)
 
Iam flattered that Barry thinks I have the answers, but when I read thru these and similar posts I sometimes wonder if I do and can give them in a clear informative way. I have a tremendous amount of practical experience manufacturing, testing and using lenses for film and video, but I am not a lens designer or an optical engineer.

As has been pointed out elsewhere, the small pixel size on these small 1/3 HD sensors creates a situation that almost requires defying the laws of physics to solve.

Forget the actual numbers, on a given format HD requires way more resolution with good contrast than standard definition. Standard def lenses are quite good, making them better is expensive, sort of the law of diminishing returns, so it keeps costing more and more to make less and less actual improvement.

Remember ( and this was also pointed out) that the inexpensive digital still cameras have relatively short zoom ranges (3x-4x not 10x to 16x like the video lenses) and are slow (f2.8) at the wide end and generally loose a stop or more at tele (f5.6 or?) and do not have to hold critical focus as you zoom (auto focus compensates for the focus shift)--- there is just no comparision of the complexity and manufacturing costs of these lenses.

As for the longitudinal chromatic aberration at the tele of the Fuji 16x lens on the new JVC HDV camera (which I noticed in a quick check the first time I saw the camera) the zoom range is 5.5mm to 88 mm, the DVX100/100a is 4.5mm to 45mm, the new HVX200 is 4.2mm to 55mm. The difficulty of correcting this type of chromatic aberration increases with the focal length (the is also a type called lateral chromatic which is a problem in wide angle lenses) so you would have to compare the lenses at the same focal lengths to be fair- and the Fuji will not show dramatic color at 50mm.

As I said in a previous post, my hat is off to those making these very high performance , relatively low cost camera's and lenses. I marvel at the bang you get for the buck.

But never doubt that there are reasons why the very high end lenses and cameras are many times more expensive, but the increase in performance is not in ratio to the cost.

And all things being equal, a larger image is potentially a sharper better image, 2/3 rds is better than 1/3 or 1/2, and 35mm motion picture film still blows away video in ultimate quality, but the quality of video keeps improving and I have no doubt that some where down the road everything we see on television and in theaters will be captured and presented digitally.

I hope this helps, let me know if there are specific questions unanswered, I will do my best to help. I am impressed by the amount of thought that goes into many of the posts on this site.

Bill Turner
Century Division
Schneider Optics
 
Still the question remains why a digital Camera with a much cheaper lens (Nikon F1, Canon EOS, etc.) is able to resolve much more resolution than a HD lens for a HD Camera? Even at 1/60th of second exposure they have comparable if not better latitude. If you look at a review of the mid-level prosumer cameras, they have very little chromatic aberration with the stock lenses. Is it marketing or real tangible technology that justifies the $$$
 
redbaron_ict said:
Still the question remains why a digital Camera with a much cheaper lens (Nikon F1, Canon EOS, etc.) is able to resolve much more resolution than a HD lens for a HD Camera? Even at 1/60th of second exposure they have comparable if not better latitude. If you look at a review of the mid-level prosumer cameras, they have very little chromatic aberration with the stock lenses. Is it marketing or real tangible technology that justifies the $$$
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I would have thought that all the previous posts would have basically answered this question. To sum it up it is many factors, but most certainly not just a "marketing" label being attached to inflate the price point.
 
Still the question remains why a digital Camera with a much cheaper lens (Nikon F1, Canon EOS, etc.) is able to resolve much more resolution than a HD lens for a HD Camera?
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I think this really is a sensor size vs. lens issue. If the sensors get bigger, the tolerances on the lenses go down - which explains why the digital still cameras can squeeze out nice 5 MP images out of cheap lenses.

-Spiff
 
Well, on my 8mp Canon 20D, the pixels are about 6.5 microns square, which is bigger than the 5 microns of the Sony HDCAM, and a lot bigger than the 5x2.5 microns of the FX1. Also, stills camera lenses breathe heavily, which video camera lenses can't get away with, and they also have chromatic aberations, which in a still image you can easily edit out - something you can't really do with video.

Graeme
 
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