View Full Version : Century Op. 16:9 questions
Samuel Murchie November 4th, 2004, 11:43 PM Hello,
Not a PDX10 or a 950 user, but...
I've been thinking about using a 16:9 adapter on my Panasonic GS100k, which has 43mm filter threads (and my TRV900 before had 52mm threads...), but I hate the idea of using the Cen. Op. 16:9 for 52/58mm threads because of the loss of zoom range. So I was looking into the 1.33x adapter that goes for over $1k.
Then...
I stumbled into the 37mm thread-mount 16:9 adapter (the one that would fit the PDX10/ 950) page on Century's site, and if you look at the Spec. section for the 37mm version, it states that THAT particular lens provides "Full zoom capability" and widens the horizontal angle of view by 30%. Check it out:
http://www.centuryoptics.com/products/dv/16x9/16x9_37mm_specs.htm
I'm posting here wondering if this is in fact the case. Full zoom? I can see how that might be the case (smaller lens, less glass, less optical distortion, less light absorbed), but I want to make sure this isn't a typo on Century's part. Also, I need to know if the horizontal angle is indeed only increased by 30%, because I'd have to use it with my matte box/ rods to support the lens. 30% is fine, but any more than that is going to cuase problems.
I have already figured out how to adapt the camera to alow me to use a 37mm threaded lens, but I really want to know it this thing is full zoom-through before I sink $300 into it. If so, it's really a sweet sollution for shooting 2.35:1 with the GS100k.
Please help out.
THanks
Samuel
Boyd Ostroff November 5th, 2004, 08:49 AM Samuel:
Several of us have thought about using the 37mm adaptor but I don't think anyone has taken the plunge. Don't you think you'll get vignetting at full wide zoom when you fit the 37mm lens to your 43mm camcorder?
Also consider what you plan to do with the footage you shoot in this "cinemascope" format. Are you upconverting it to HD? If not then there is probably no advantage to using the adaptor vs just letterboxing inside the 16:9 frame. For example, if you are burning to DVD then your final product will have to be 16:9 with a 2.35:1 letterbox anyway.
As always, I'd also be interested to hear from anyone who has actually used the 37mm anamorphic to create 2.35:1 as you describe.
Samuel Murchie November 5th, 2004, 11:27 AM I'm not concerned with vignetting because- as with most cameras in this class- the actual lens diameter of the GS100k is about half that of the barrel threads. I would estimate that the actual lens diameter is about 22-30mm, and even though the PDX10 barrel thread is 37mm, I am almost certain that the lens itself is NOT 37mm in diameter either.
On the GS100k (as I believe on most Sony's) you can disassemble the front of the lens assembly, removing the front threads and light shield/ shade. When this is done, the lens is completely exposed, and there is actually a second set of lens threads under all the crap you just took off. On the GS100k, these threads are also 43mm, but it gets you MUCH closer to the front element of the lens. My plan is to use my matte box and rods to mount the 16:9 lens in front of the GS100k lens, and then stack step-up rings to fill the gap between the barrel assembly and the body of the 16:9 lens (sounds complicated and ugly, but it's really quite practical...)
As far as the HD conversion, that's a posability. I've been searching for a detailed discription of the workflow, which I haven't found. The GS100k actually has a very good "fake" 16:9 that uses pixel compression rather than masking off the top and bottom and sacrificing resolution. I believe it's the same fake 16:9 that Panasonic employed for the DVX100A (actually, I'm pretty sure it is).
Fankly, I've always wondered why it wouldn't be possible to simply shoot in 16:9 (compress/ stretch mode) with a 16:9 adapter and simply decompress the footage twice: one pass through your NLE program would decompress the fake 16:9 that your NLE recognizes > output to tape as letterboxed 16:9 > decompress again as you would with footage shot with an anamorphic lens (which your NLE doesn't recognize anyway) > 2.35:1. I realize this puts an enormous amount of strain on the resolution that a 1/4" chip can produce, but it's certainly worth a shot.
I want to shoot with an anamorphic lens simply because of the way the anamorphic process affects the image quality (light and color distortion). I think that what people precieve as "cinematic" has a lot to do with things that are unconscious and that they can't articulate. DOF is obvious, and people are slowly catching onto the psychological difference between 24 fps (24p... whatever...) and 60i, but there are other things (like analogue sound and anamorphic compression) that affect how people precieve films compared to stuff shot on video...
Boyd Ostroff November 6th, 2004, 10:36 AM Martin Munthe is someone who has used this technique and written about it here. Unfortunately the links in his posts no longer seem to work, but you might find these threads interesting. The examples he posted looked great, too bad the site doesn't seem to be there anymore. I believe you can get his movie on DVD however.
http://www.dvinfo.net/conf/showthread.php?s=&threadid=3069
http://www.dvinfo.net/conf/showthread.php?s=&threadid=6483
You lost me with that talk about "decompressing" your footage and it sounds like a lot of trouble when there would be a more direct way. Quicktime should let you render a file with any pixel dimensions you want, so just set the frame for 480x1128 and you have 2.35:1.
But getting back to your original question, I think the two of us are just theorizing for our own amusement since obviously nobody has actually bought a 37 mm adaptor and tried this. Hey, why not be the first and then write up a report for the rest of us? :-)
John C. Chu November 9th, 2004, 07:38 PM I tried the Century Optics 16:9 37mm version on a camera with 46mm threads using a step-down ring and ufortunately, it will vignette.
[I, too, wanted to save money] Thank goodness B&H Photo here in New York took it back no problem. [I tried it for ten minutes and realized it wouldn't work...]
You could zoom in slightly to eliminate the vignetting---but you will then lose most of your wide angle range--and everything will be telephoto. [not good..]
If you still intend to try it...just make sure you can return it if it doesn't work right for your application.
You can definitely do the double 16:9 to achieve a 2.66:1 aspect ratio--but you could just also just shoot 16:9 and crop/hard matte the frame.
Another option for doing "Cinemascope" on video inexpensively is to look for a Bell and Howell 2x anamorphic lens on eBay... you can sometimes get them for about $60-100.
You then need a series 7 adapter to whatever thread size you have...
This works great and you get all the nice anamorphic flares--distortions etc...that cinematographers talk about...but you have to make sure the lens is aligned vertically and you have keep the camera level--otherwise your horizons are all screwy.
But you have to do some rendering though..[I had to 'apply' the 16x9 filter once to fit it in a 16:9 enhanced frame[the widescreen tv does the rest] or apply the filter twice to render to fit in a 4:3 frame]
Good luck!
Samuel Murchie November 11th, 2004, 09:51 PM Double 16:9 would be 2.35:1.
The Kowa 2x would be 2.66:1.
I need something that doesn't increase the angle by more than 30%, because my matte-box well then be useless (and it costs more and is far more valuable artistically than the 16:9 adapter...)
What camera were you shooting with?
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