Which MiniDV camcorder

[Rob100]

Thanks. I think a trip out at the weekend may be required. I have just sent the company an e-mail to see if they have both in stock so I could try out if I was to make the journey.

Thanks (as always) for your advise.

Is there any chance you could upload a small (even just 5 seconds) DV clip shot with a 3CCD camcorder so I can see what to expect? Alternatively do you know anywhere you can download sample footage shot with different camcorders? Unfortunately I'm still having to use dialup 56k here :-( so I don't want anything too big!

Edit: Thinking again, that would still be quite a download... How about a couple of still frames grabbed from some DV video?

Rob.

[Rob100]

I've just found some sample stills taken with the MX300 and I am amazed by the quality.

http://www.camuser.co.uk/articles/frame.html?http://www.camuser.co.uk/articles/misc/200109/200109.shtml

At times like this I start to think "what the hell, you only live once"... Where's the plastic ;-)

[Jerry Jones]

I'm afraid you're not going to necessarily get an accurate feel for the difference between 1CCD and 3CCD camcorders just by comparing a couple of clips.

The fact is the performance of 1CCD and 3CCD camcorders (which I use frequently) can vary *dramatically* in any given lighting situation.

I use a Sony DCR-VX1000 at work, which is the 3CCD camcorder.
I also use a 1CCD Canon ZR20.

At one time, I also owned a 1CCD JVC GR-DVM5U (which decided to die one day).

Well... I recorded video of two identical scenes using the JVC GR-DVM5U vs. the Sony DCR-VX1000. The video taken by the Sony DCR-VX1000 on that particular day was far, far superior to the video recorded by the JVC GR-DVM5U.

I then waited a few days and recorded video of the same outdoor scene using the Canon ZR20 and the Sony DCR-VX1000.

I was astounded by how close the material shot by the Canon was to the Sony... the lighting conditions were just right for the 1CCD Canon on that day. Plus, I am convinced the Canon camcorder - in spite of a CCD technically comparable to that of the JVC - is superior. I suspect the Canon lens is also superior to the lens on the JVC.

But a couple of things will almost always distinguish the material shot by the 3CCD camcorder:

1. the colors will almost *always* be richer
2. the resolution of fine details such as leaves of plants and shrubs will almost always be finer

[Brian Ellis]

Let me expand a little on the question of resolution. With all "traditional" cameras, using electronic tubes as the sensors, such as the image orthicon, plumbicon and so on, there is no notion of pixels. The photosensitive area can be considered as a continuum. The resolution was therefore relatively unrestricted by the tube itself but more by the associated electronics. The luminance was therefore derived from the tube nearest the middle of the spectrum, i.e., the green.

When the three-CCD prosumer mini-DV camcorder was initially developed, the first offerings followed the same theme, even though the CCD has a finite pixel. This actually limited the resolution, but this did not especially matter, because there was neither DV-IN nor DV-OUT, just a high-quality analogue output. At this time, the CCDs had typically a 300,000 pixel rating, each. This gave a horizontal resolution of about 350 equivalent lines, as opposed to about 250 for other camcorders, so the result was a visible improvement in resolution and a very distinct improvement in colour rendering. Then Panasonic had a genial idea, first brought out in their NV-DX1 3-CCD camera (still analogue out) and since copied by the other makers. They said that, instead of putting in larger CCDs with a higher resolution, let's position each one so that the pixels of each CCD are 1/3 away radially from each of the others, so that there are a total of 900,000 pixels, each in a different position on the image. From them, they were able to derive a much better luminance signal, where there were no single saturated colours, a composite of the three signals. This improved the resolution by a factor of about two and so took the theoretical resolution above the practical resolution that the compression limited in DV of about 500 horizontal equivalent-lines. The result was a visible improvement, even on ordinary TVs which came nowhere near being able to resolve this kind of definition. This is why a 3-CCD generally should have a better resolution than a 1-CCD, even where the latter has a bigger CCD.

However, there is a limitation: the lens. Even a number of 3-CCD camcorders had lenses which were not much better than bottle-bottoms. The Panasonic NV-DX100 series cameras, for example, had a comparatively poor lens, as did some other "low-cost" 3-CCD cameras of the late 1990s/early 2000s. As the lens should be the single most costly component in a camera, it was here that the greatest economies were made, combined with the desire to have greater zoom ranges, as a sales argument, but which limited the resolution terribly. I think that, in the past year, this limitation has been realised and efforts are being made to have better lenses but "you pays your price and you gets what you pays for". My advice there is, for a given price level, buy the camera with the shortest zoom range and certainly not more than 12:1, preferably 8:1. With chemical cameras, a good lens is limited to 3:1. I have a superb super-8 film camera which has a lens which weighs about 2 kg with a 10:1 zoom ratio. This was possible only by using some special, extremely expensive, optical glasses and was really state-of-the-art but even this will not hold its focus perfectly over the 7-70 mm range at some focal distances. Yet this lens is infinitely better than (and costed infinitely more than) the apologies for lenses in today's camcorders. In today's money, this lens would probably cost about $7,500, and I would dearly love to have something similar on a 3-CCD camcorder (and probably could if I went fully pro at a price which would drive me into poverty).

[Dr Mordrid]

Brians right in regards to the lens on camcorders. This was also painfully obvious when Digital8 first came out.

While most DV cams by then had moved on to at least slightly better lenses Sony recycled a lot of their older 8mm lens packs in the D8's. Result: a cheap digital camcorder with optics that were very inferior. Fortunately Sony has moved to (slightly) higher quality lens packs in their newer upper end D8's.

This still doesn't resolve the problems with lens quality on modern camcorders though. All one has to do to see this is to look at a USAF lens test done using the camcorder of your choice (capable of shooting a megapixel still) vs. a 35mm camera with a digital back shot at ~ the same resolution and a quality lens.

The difference is amazing.

Dr. Mordrid

[bill2]

There is one important point that nobody has mentioned - the option to make a professional print of this DV snaps.

I'm sure that sooner or later you will find that you like to send this lovely pics you have to one of the places that send you back your photos printed on 4" x 6" quality paper (such as - http://www.agfa.com/photo/products/e.../agfanet_print and so on)

Unfortunately it happened to me after I film the delivery of my daughter with my NV-DS15 when I discovered that the resolution is fine but the frame size is too small (118 pix/cm @ 6x4 cm)

I think it is something that worth a second thought.

[Hulk]

How do DV camcorders that take stills at higher resolution then they record video work?

Do they use the same CCD for both video and stills?

If so I suppose the pixels are downsampled for the video stream? That seems like a lot of math for a realtime stream though... hmmm, now I'm very curious.

I've been wondering about this since the current crop of dv camcorders that can do 1megapixel+ stills began to appear.

[Brian Ellis]

Hulk

You can buy saw, orbital polisher, hedge clipper, even lathe attachments for an electric drill. None of them work well. You can also buy a camcorder with still photo facilities but the latter are more a sales argument (that costs almost nothing extra) than a serious tool.

I have such a camera and I have used it for photos to illustrate reports - and it was adequate for that. But try to print out an A4 size glossy on a photo-quality printer and you will be disappointed unless you are blind in one eye and cannot see with the other. Again, the lens will not have a quality that will be commensurate with the job: it is built down to a price and is often barely good enough for video, let alone stills.

It is all commercial hype. Don't be taken in.

I realised this when I splashed out a year ago and bought a 4.3 Mpixel still camera, which is optimised for that job (it will also take about 12 minutes of video at 640 x 480, 15 fps, MJJEG), but I have never used it for that. With it, I can print an A4 glossy and, at a casual glance, it could easily be mistaken for a chemical print. At A5, it would be difficult to tell whether it was digital or chemical without a good magnifying glass. But then, if I use it at max resolution, uncompressed, each shot consumes 12.7 Mb of RAM and I have the choice between 9 resolution/compression settings with a CCD which is 25 x 43 mm and a commensurate lens. Incidentally, it has a zoom range of only 6:1 and this is exceptional for such a still camera, but the price for this is that it's limited to f 2.8 widest aperture. I've determined best results are at f 5.6-8. Also, the macro facility on this lens is also relatively limited. Incidentally, remember also that a zoom lens on a still camera does not have to maintain perfect focus over the zoom range because you frame, then focus (assuming you do not let the camera do it for you). With a video, you don't want it to blur as you zoom in or out, although they do.

So, if you wish a decent result, use the right tool for each job.

[Hulk]

Brian,

Thanks for the great info. I appreciate you taking the time to respond. I am not considering such a camera, I also believe that each device is best suited for one function. I was only wondering if these cameras that capture video at one resolution and stills at another have one or two CCD's? I'm wondering how they work from a technical, or engineering standpoint.

Mark

[Brian Ellis]

Mark

I suspect they have a single CCD but that the video image is derived by "short-circuiting" groups of pixels together electronically to DV standards. As the yield in CCD manufacturing is not as high as with most semiconductors, with consequent high manufacturing costs, this would make economic sense, but I cannot be categorical.

[Dr Mordrid]

This is pretty much how it works.

In the megapixel video cameras they shoot the stills using the largest portion of the CCD while applying a logical mask to shoot the video.

Those cameras with image stabilization move the mask around the CCD according to the needs presented by camera motion.

Dr. Mordrid

[Hulk]

Ah! Excellent! This was/is a very informing thread.

My mother is a professional photographer. She is old school, not really into the digital stuff at all, she spends all day in the darkroom and shoots with box cameras. Great results though, sometimes I look at the prints from her Hasselblad (sp?) and am just amazed.

Anyway, she always tells me, "remember, you're paying for the glass!" whenever I tell her I'm buying a new camera. I guess she is right.

[Dr Mordrid]

Yup, the glass is the thing. That and the coatings. What's *REALLY* nice is when you have a nice film camera with a digital back.

Then you can use that fancy glass, or a good mirror lens, with digital imaging and get just gorgeous images. I have both a 250 mm and a 500 mm mirror and just love 'em.

Dr. Mordrid

[Hulk]

You would think that with modern manufacturing techniques really high quality lenses would be affordable these days. There are still some 20 and 30 year old German lenses that I hear pro photographers raving about to this day.

Then again, look what happened to Hubble...

Then again, again, look at the amazing fix!

Mark

[Brian Ellis]

Mark

It is true that some of the German lenses were superb. Even the Leitz Elmar f 2.8 fitted to the prewar Leica cameras (pre '39-45 one) was able to resolve over 300 lines/mm at the edges at full aperture, at any focal distance over about 1.5 m. Lower down the range, the Zeiss Tessar f 3.5 was fitted to many 6x6 or 6x9 cameras using 120 or 620 film and could do well over 250 l/mm (resolution was slightly less important for these longer focal-length beasts, because the surface area of a 6 x 9 film was 6.25 times greater than a full frame 35 mm film). These and other similar lenses were expensive to manufacture because they were no-compromise designs. The lens designer specified the qualities of the optical glass required for each component and the glass was made to that specification. Each batch was tested before use and if, for example, the refractive index at different wavelengths was out-of-spec, then it was either remelted and corrected or, more often, it was thrown on the scrap heap. As the optical qualities depended on the addition of "rare earth oxides", this was necessarily very expensive.

The superb Japanese single-focus lenses, made by Asahi, Canon and Nikon in the 1950s to 1970's for their respective 35 mm cameras, were much cheaper than their German counterparts and very marginally poorer in quality, although many could resolve up to 400-450 l/mm. This was because each batch of optical glass was used, but the characteristics were initially measured and, if necessary, corrections were made in the individual components during grinding and polishing or in the assembly, to compensate for the tolerances. This gave a much higher yield, because of this mindset.

I've totally lost touch with the optical world but I know that plastics for some of the interior components of low-cost lenses have revolutionised the consumer/prosumer camera industry. Many pros (newspaper reporters excepted for obvious reasons) eschew zoom lenses for still photography as they are still not a match for single-focus lenses and much of the professional imagery still uses cameras like the Hasselblad and even such twin-lens monstrosities like the Rolleiflex in much the same way as, in my youth, they often used whole-plate cameras with superb 8" x 10" contact prints for portraiture, fashion and publicity photography. Incidentally, I still have a 1/4-plate camera in mahogany and brass, with an f8 rapid rectilinear lens. I used it in my youth, when plates were still available, largely for architectural photography, because I could stop it down to f64, giving needle-sharp images, with a good depth of field. Unfortunately, both the negative plates and prints disappeared in the 1950s during a house clear-out (I also lost 2 2-1/2" x 3-1/2" plate cameras at the same time, to my eternal regret), when someone thought that it was all old junk, when I was away.

There I go again, rambling on with my reminiscences