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Old November 16th, 2005, 06:27 PM   #1
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Kurt and his Letus35A

Hello and greetings from a little Pal country. I received my Letus some time ago, but due to a rather serious optical misalignment, I opted to try to put the adapter crooked, so the frame is aligned... weird but let us hope it works. Today I finally whacked some polyester paste on my rod support, so the construction would at least be temporarily stable. I didn't come around to serious cleaning and testing afterwards, that will be something for the next couple of days. I will post everything here.

After the mess dried up, I just had enough time to quickly point and shoot. So let's post it for the sake of all people dying to look at the dailies everybody makes with their Letus.

http://www.lesoup.com/fileadmin/user...amamasq264.mov (11mb, 10 sec. 768x576 px, encoded quicktime h.264)

Lens Nikkor 50mm f 1:1.4
Camera: Sony PD-150p, 25fps, shutter 1:50, f2, 12dB on the shot inside
No cc, just flip and field of view correction.

Don't be afraid. It just very short the house I grew up in and my mother eating (here she is a bit further away http://www.lesoup.com/fileadmin/user...ate/mamama.jpg ).

Shot 1 is to show the frame is centered, although my adapter is now off-center an absurd amount. I corrected the barrel distortion in post.

Shot 2 is shot inside. The only light source was a smal kitchen lamp. Therefore I had to open up the nikkor completely and add gain in the camera. Normally I would prefer a less shallow depth of field. I don't really like it when focus is on two or three wrinkles.

What I noticed is how nice it scales full screen on a large monitor. Probably because it's just a bit too soft.

What's on the programme the next days? Test charts, cactusses and 24, 35, 50 and 200mm lenses. I don't promise footage as sharp as some of the M2 footage I've seen, but it should be fun.

Thanks, Kurt
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Old November 16th, 2005, 07:07 PM   #2
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Hello kurt, thats not too bad its looks workable. Keep up the good work.

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Old November 17th, 2005, 05:12 PM   #3
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Me me me and dust

Some grabs:

http://www.lesoup.com/fileadmin/user...vate/haar3.jpg (that's her)

http://www.lesoup.com/fileadmin/user...ivate/hem2.jpg (that's me)

And all of a sudden: DUST between GG and anchromat, a hard place to get to.

http://www.lesoup.com/fileadmin/user...te/haarr2c.mov (5mb, 768x576 H.264 and so on)

Here you see the specks very clearly, although they're very tiny. Damn them! Now I have to open op the adapter completely. This way I will never get around to shooting test charts.

Last edited by Kurt August; November 17th, 2005 at 08:36 PM.
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Old November 18th, 2005, 01:36 AM   #4
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Those snaps and footage of the doll head (?) are very nice. Remarkable how the DOF provided by the lens/Letus very much changes the basic look of the picture. For instance, the nose and face are sharp, but the hair in back is soft. Really great.

Thanks!
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Old November 18th, 2005, 03:41 AM   #5
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Thanks for the images, Kurt. I am having a soft focus problem with my adapter that just arrived yesterday and these pictures help keep me motivated to get everything working.
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Old November 19th, 2005, 05:42 PM   #6
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Oranges and apples

What's the most boring to film? Apples and oranges.

So here it is, and pretty ok (just don't mind the dv artefacts):
http://www.lesoup.com/fileadmin/user...nges4b_264.mov
(f5.6, 12mb, 12 sec. h.264 when the orange turns it's too blurry through motion blur, but deinterlacing looked terrible in the static parts)

I wanted the depth of field to be normal. Not too shallow, like we see mostly. Although it is not soft, I do think that we are a bit fooled by seeing a large orange. If this was a wide shot, I don't know if it would feel sharp enough.

Important: I hope I will get sharper images when I can use a lcd monitor next week. All these shots are focussed on a large television.

These stills are taken from the film:
http://www.lesoup.com/fileadmin/user...nge_still2.jpg and http://www.lesoup.com/fileadmin/user...ange_still.jpg
And this one during focussing:
http://www.lesoup.com/fileadmin/user...nge_still3.jpg

It is really sharper. So good bye illusion of being focussed as good as possible.

With one thing I am not so happy. There's a small piece of paper in the clip. It has these typical adapter abberation.

I have been thinking.

I see a lot of movies and a lot of tests with adapters. One thing that always looks terrible is how white highlights, give optical defects. Just look good and you will see it everywhere. I'm NOT just talking about the Letus!

I've made an example:

http://www.lesoup.com/fileadmin/user...ate/faults.jpg

Ok. My theory. Please correct me if I'm wrong:

These defects are always there with the consumer and prosumer cameras we use. But because we optically use a rather small area, these defects are blown up, as in the example.

Does this mean we will always have to avoid white highlights? Really? Come on, every shot would require special checking!
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Old November 19th, 2005, 09:10 PM   #7
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The soft glow around highlights is one of the things I most like about the 35mm adapters! To each his own...I guess that it's just like the difference between apples and oranges. :)
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Old November 19th, 2005, 10:17 PM   #8
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White highlights bugging you, Kurt? Well, they're quite tasteful if used correctly. Just realize that no matter what Andromeda mod or 35mm adapter you throw at these DV cameras, none of them are going to take in light as well as film can (unless you wish to spend $100,000+, which includes just one to two lenses). Yes, I've noticed flaws with my own DIY 35mm adapter, the M2, some shots of the G35, little flaws like every other adapter has, there's no perfect solution for everything. Really it's just a matter of whether these little problems really bother you or not, I don't mind, I like the look a 35mm adapter gives to my footage. Nice choice on the Letus35A BTW, that's one of the adapters I've wanted to try and it looks really nice, thanks for the wonderful screens and footage! =)
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Old November 20th, 2005, 05:42 AM   #9
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Glow

Marcus, I agree about the glow, I must add that especially the Letus often handles the light very well.
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Old November 21st, 2005, 11:55 AM   #10
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Test chart

I've added a testchart, so you can clearly see the most important defect: the barrel distortion. The slight light fall off is because of the lighting: one redhead with softbox, the testchart is also rather large, 120cm wide. Yes, you lose some resolution. But this testchart is more critical than the one developped in 1956.

http://www.lesoup.com/fileadmin/user.../private/4.jpg

Last edited by Kurt August; November 21st, 2005 at 02:19 PM.
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Old November 21st, 2005, 08:16 PM   #11
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Test chart 1956

I also quickly shot the 1956 testchart. Printed out on a smaller piece of glossy paper. Badly lit. I just adjusted the back focus of the adapter and wanted to check my sharpness.

Quyen, Thanks for the instructions.

still:
http://www.lesoup.com/fileadmin/user...e/quickie2.jpg
movie:
http://www.lesoup.com/fileadmin/user...te/quickie.mov (pd-150 pal f2.8, nikon 50mm f5.6)

Update:

This one is shot without the adapter:
http://www.lesoup.com/fileadmin/user...ormal_lens.jpg

Hm, the Letus holds up pretty well.

Further lazy footage (flipped only):
http://www.lesoup.com/fileadmin/user...te/stapler.jpg
http://www.lesoup.com/fileadmin/user...e/stapler2.jpg
http://www.lesoup.com/fileadmin/user...ate/straat.jpg

Last edited by Kurt August; November 22nd, 2005 at 09:32 AM.
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Old November 21st, 2005, 09:35 PM   #12
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I think it may have something to do with the macro. I just got my Century Optics achromat off ebay which should be arriving within a week or so and I'm dying to swap it out with the one in the Letus. I'll post results when I can.
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Old November 21st, 2005, 09:53 PM   #13
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Please do. I'm very curious. I thought the condenser was to blame.
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Old November 22nd, 2005, 05:29 AM   #14
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Yes, the distortion is indeed coming from the condenser lens.
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Old November 22nd, 2005, 08:52 AM   #15
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CCD misalignment.

Just a quick message to people who want to use their Sony PD150 with the Letus, or any other added glass.

Sometimes, the CCD block is not perfectly aligned with the lens. I've read earlier that this can occur with this camera family. In normal conditions, you wouldn't notice, but in our case, it is of some importance. I posted a quick test, it's just a found grid placed in front of the letus tube (or any other tin). I think it speaks for itself.

http://www.lesoup.com/fileadmin/user.../ccd_fault.jpg

So what's the big deal? The condenser gives barrel distortion. But I need the gg in the middle of the image, because only then can I zoom in enough. Then of course the barrel distortion becomes asymmetrical, which I don't like.

So what's the best solution? Do you have a clue?

Perhaps, ideally, I should make a construction in which I can move the adapter a couple of mm's horizontally, or parts of it. I don't know. Suggestions are welcome.

I had the same problem with an Optex 16:9 converter.

I thought I'd share this, perhaps someone else can avoid breaking his head then.
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