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Old January 2nd, 2006, 04:10 PM   #1
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Letus35a Image Sharpening Techniques ???

I've had my Letus35a for a few weeks now and I can't seem to find that sharp sweet spot. The L35a is attached to a Panasonic GS250(2.5" lcd screen), Canon FD f1.4 35mm lens, and camera focus is set to manual.

Do any of you Letus owners have the same issue with an overall blurry image ?

Here are a few video tests : http://www.probe3.com/3ccd/Letus35a/

Thanks!
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Old January 2nd, 2006, 08:15 PM   #2
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This image is very sharp.

http://www.probe3.com/3ccd/Letus35a/index.php?id=2

??
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Old January 2nd, 2006, 09:17 PM   #3
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I think that's just the nature of the beast. I don't know why you're calling those images blurry, because they're (especially the ones of the cars outside) pretty darn sharp. The adapter does naturally soften the image a bit, although most people like that look. I really don't think there's a way around it.
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Old January 3rd, 2006, 09:19 AM   #4
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Mark:

This may be a bit more than you're asking for, but I'll include it for you and any others that are interested.

I have done some testing with the Letus 35A and Canon GL2 and what I often do is turn the sharpness on the camera DOWN. (Ok, the opposite of what you're looking for) The reason why is that it is sharpening a relatively low-rez (720x480) image, which lends itself to pixel aliasing that is readily-visible. Not to mention that any visible grain will be even more visible with sharpening.

So...I take the 'soft' footage and bring it into After Effects (you can use most any NLE also) into a comp. that is 1920 x 1080 (You can use any resolution your computer can handle, really - just keep the aspect ratio. You may have to letterbox.) I throw a solid color (usually 50% grey (( 128,128,128 )) ) layer over this and add some moving grain to this (not heavy - this isn't for the grain effect, but for the appearance of higher resolution ). Once the grain looks fine, I set the transfer mode (overlay, etc...). They I'll precomp this in a new layer and use the Unsharp Mask filter, adjust cuves/color, etc... and render. You can take it back out to 720x480 at this point if you want.

Ok, the theory is that you are introducing the sharpening at a 1920x1080 resolution instead of 720x480. Why can't you just blow the image up and sharpen it without adding grain? Think of enlarging the footage as making the pixels bigger (with standard algorithms, anyway). Sharpen filters work by checking the contrast between neighboring pixels. The contrast between, say, a red and green pixel is the same between a block of 4 red and block of 4 green pixels. The grain overlay adds variation to the enlarged pixels, giving the sharpen filter finer detail to bring out.

This may sound a bit wierd, but think about it and give it a try.
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Old January 3rd, 2006, 11:21 AM   #5
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Hi Bill,

I didn't mean the photos of the unit, I meant the video footage, I took a few screenshots from the uploaded videos:
http://www.probe3.com/3ccd/Letus35a/index.php?id=2

These are the desired results screenshots:
http://www.probe3.com/3ccd/Letus35a/index.php?id=17


Thanks for the TIP Frank !, I'm trying your suggested technique right now :)
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Old January 3rd, 2006, 11:25 AM   #6
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That's from macgregors footage isn't it. the G35.
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Old January 3rd, 2006, 11:41 AM   #7
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Originally Posted by Yasser Kassana
That's from macgregors footage isn't it. the G35.

Yep, I love how it looks "Hyper-Real". I'm wondering if I can achieve similiar results if I use reflectors like he does, to light the object on both sides and not just a directional from the sunset. I think he uses that technique to allow the main subject to pop forward from the blurred background.

Have they announced a price for the G35 yet ?
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Old January 3rd, 2006, 02:32 PM   #8
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I love Macgragor's stuff too, but he has an FX1, not a gs250.

I don't know if its fair to your gs250 to compare it to an FX-1. As far as cameras go that's a bit of an apples to oranges thing.

I have a gs150 with the Letus35a and I've gotten some great stuff from it. Here's some screenshots: http://www.soride.com/blog/letus35-tests-round-i/

But I'm not expecting DVX or FX-1 quality footage. It's just not a realistic expectation for this class of camera.
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Old January 3rd, 2006, 08:40 PM   #9
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Frank, I'd love to see your method in action. It sounds like it would work pretty darn well. I'm itching to try it out, especially since I got my Letus back from Quyen and a 55mm 1.2 today, but it looks like it'll have to wait until late tomorrow afternoon. (uggh). Good luck.
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Old January 3rd, 2006, 09:24 PM   #10
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frank, could you show us any examples of your sharpening technique? i'm intrigued...
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Old January 4th, 2006, 01:32 PM   #11
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I just shot all this great footage with my GL2, and I was all ready to try this out...to find that my computer doesn't recognize any firewire devices. AY IEEEEE! (1394)
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Old January 4th, 2006, 01:43 PM   #12
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Quote:
Jamie Niebuhr: frank, could you show us any examples of your sharpening technique? i'm intrigued...
Quote:
Ben Winter: Frank, I'd love to see your method in action.
I'll try and get some footage together today or tomorrow for you guys to check out.

Also, I'll try to throw in a couple before-and-after frames and some screengrabs.
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Old January 4th, 2006, 01:48 PM   #13
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I got my FireWire working now...Frank, could you give me some details as to the settings you're using in AE for noise? I'll play around some, but I'd like to know from soneone more experienced what ideal settings would be.

I'm looking at my footage and it's looking pretty darn sharp on my production monitor. I don't really know how much more this could be improved.
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Old January 4th, 2006, 03:45 PM   #14
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Ok I tried this lastnight. Here's what I did:

I used this footage: http://www.probe3.com/3ccd/Letus35a/L35A_beerZoomIn.zip

720x480, 16x9 ratio

1. Made a comp of 1920x1080 in AE 6.5 pro.
2. Upscaled my footage to that size
3. added 128,128,128 solid over it
4. added grain, intensity set at 15
5. set layer to overlay
6. PreComposed both layers then added Unsharp Mask,amount set to 20

Rendered the result as uncompressed AVI. It seemed like it would take 5 hours to process. So I killed the render and made the comp size to 1280 HDp res.

Then used the output avi in a new comp where I brought it back down to 720x480, 16:9.

I don't think I did the process correctly because the result was footage that had undesired visible sharpened noise.

Would love to see how you did this Frank ! :)
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Old January 4th, 2006, 04:31 PM   #15
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Quote:
Originally Posted by Mark Wisniowski
Hi Bill,

I didn't mean the photos of the unit, I meant the video footage
LOL, I know. I was going for a cheap laugh, or at least that someone would think I was an idiot. I will try harder next time.

P.S. the PAL-style mayonnaise is working out beautifully for me.
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