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_upload/kurt_augustyns/private/chezmamamasq264.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_upload/kurt_augustyns/private/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

Hello kurt, thats not too bad its looks workable. Keep up the good work.

Anhar

Some grabs:

http://www.lesoup.com/fileadmin/user_upload/kurt_augustyns/private/haar3.jpg (that's her)

http://www.lesoup.com/fileadmin/user_upload/kurt_augustyns/private/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_upload/kurt_augustyns/private/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.

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!

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.

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_upload/kurt_augustyns/private/applesandoranges4b_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_upload/kurt_augustyns/private/appleandorange_still2.jpg and http://www.lesoup.com/fileadmin/user_upload/kurt_augustyns/private/appleandorange_still.jpg
And this one during focussing:
http://www.lesoup.com/fileadmin/user_upload/kurt_augustyns/private/appleandorange_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_upload/kurt_augustyns/private/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!

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. :)

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! =)

Marcus, I agree about the glow, I must add that especially the Letus often handles the light very well.

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_upload/kurt_augustyns/private/4.jpg

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_upload/kurt_augustyns/private/quickie2.jpg
movie:
http://www.lesoup.com/fileadmin/user_upload/kurt_augustyns/private/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_upload/kurt_augustyns/private/normal_lens.jpg

Hm, the Letus holds up pretty well.

Further lazy footage (flipped only):
http://www.lesoup.com/fileadmin/user_upload/kurt_augustyns/private/stapler.jpg
http://www.lesoup.com/fileadmin/user_upload/kurt_augustyns/private/stapler2.jpg
http://www.lesoup.com/fileadmin/user_upload/kurt_augustyns/private/straat.jpg

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.

Please do. I'm very curious. I thought the condenser was to blame.

Yes, the distortion is indeed coming from the condenser lens.

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_upload/kurt_augustyns/private/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.

Ok, small update if you would have a ccd misalignment on your Sony.

Quyen's adapter is flexible enough to handle this.

I just took a very small drill, one they use for engravings. Since the macro ring is made of plastic, it's quite easy to shave some plastic off at one side if you have opened it (I also removed the lens). It just takes some patience. On the other side you add some plastic. I just took the glue gun. The macro stays in place, the rest of the construction is moved just a bit, just enough.

See? http://www.lesoup.com/fileadmin/user_upload/kurt_augustyns/private/DSC00028.JPG

Now, my frame should be centered and straighter when i get this whole thing back together. I'm actually starting to have some fun with this DIY'ing.

End of diary...

Now two questions.

Has anyone experimented with ideal distances from condenser to ground glass? My guess would be, the closer the better, right?

Has anyone experimented opposing two condensers to each other with this adapter?

To anyone interested:

I experimented with different distances between the ground glass and the condenser, and my conclusion was that there is less distortion as the condenser gets farther away from the ground glass, however the caveat is that the light begins to scatter, i.e. there is more of a hotspot. This is probably why it's ideal to have the condenser somewhere in-between. My firewire is acting up so I'll try to post some example shots once I get it working again.

Also,
The century optics diopter switched out with the Letus' stock macro eliminates all chromatic abbheration issues--that is, issues outside normal levels. My understanding is that all lenses create some kind of blue scattering around the edges of brightly lit surfaces and areas like skies, etc., but we were obviously seeing some extensive abbheration because of the faulty/low-cost macro. Using the Century Optics +7 has really helped my image quality. Keep in mind that if you use it, be prepared to shave a little bit off of the inside of the Letus' plastic lens mount since the diameter of the Century Optics is a tad bit bigger--perhaps half a millimeter or so.

Besides this, however, there is a massive difference in size. The CO macro is a good two/two and a half times thicker than the stock macro in the Letus and at least three times as heavy. It's a nice tight fit, but I'd even more strongly recommend using a rod support system if you go this route. As an added bonus, the Century Optics macro comes with two screw-on covers that fit both ends of the Letus perfectly. Cheers.

An old post by myself concerning condenser distance vs barrel distortion.

http://www.dvinfo.net/conf/showthread.php?t=50884

Another thing to note, is the further away the condenser is from the ground glass, the more colour seperation.

Ok. After so much nagging on this forum (by me), I threw together a short movie. And what better title than 'Aberration', my favourite word the last couple of weeks. Uploading it was hell since I'm on dial up for the moment.
It should be here though:

http://www.lesoup.com/fileadmin/user_upload/kurt_augustyns/private/aberration.mov (QT7 h264 11mb 2 min. 30 sec. 720x440 pixels. I didn't stretch it to 768 because it would reduce resolution)

Please take a look at it. Let me know if I wasted two minutes of your life or not.

Note that:
Because I was filming something geometrical, the barrel distortion was really bothering too much. So I had to deinterlace, correct it and such things, which resulted in a lot of post effort and artefacts and the evident loss of resolution. But it's mmmkay now.

To compare, here is a still from the original shoot. Just flipped. Don't count resolution. I filmed much wider than the correct test distance. But for the movie, I didn't wanted to chop of the chart at the 4:3 markings.

http://www.lesoup.com/fileadmin/user_upload/kurt_augustyns/private/aberration_still.jpg

Here are some final thoughts on the Letus. I'm sure you don't need them. The forum is spoiled by test results by now. Recent developments have perhaps made them obsolete. But I've started something and want to finish it, even though I have lost a lot of time by being ill.

Negative:
-Terrible back focus. A glue gun is not really so exact to work with. Especially difficult for wide angle lenses, if my feeling is correct.
-I had to realign every part as good as possible. I don't even know if it helped. It sure taught me how it works, and that it's easy to repair. So don't be afraid to mess with it (perhaps this is more a positive point)
-Too much chromatic abberation.
-Stretching of the image.
-I would like a lens lock. Some day I will have it too.
-Some fine grain indoors. Can be a problem if your output is dvd. As in my case.
-Glue and tape works better for me than screws in aligning the ground glass plane and condenser.

Positive:
-Available. Meaning it's here. Now. No pre-orders. No long waiting times.
-Excellent price point.
-Less problems with dust than expected. It's completely demountable. I even cleaned the ground glass (Removing glue with cutter knife, lens fluid and warm water).
-The plastic had in my case the advantage of being able to adjust it a bit for aligning it with my ccd's
-Great light diffusion in highlights. Nice colour feeling.
-Great support from Quyen and he's still continuously improving the product.

And that's it. No more indoor testing. I feel confident enough to go using it in the field. Perhaps even with living people. I will compose my shots trying to hide the barrel distortion and keeping the light controlled.
The adapter isn't perfect. But no adapter can be. It's inherent to it. But I love it anyhow.

Greetings, Kurt

What color temperature (in Kelvin) was the light you used? Is there more chromatic aberration in lower frequencies or higher color frequencies?

I'm not sure, but I think some of the sounds included were forbidden.

Kurt that was impressive - probably the best test i have ever seen for an adapter yet. Nice work. I think you should feel confident on taking your letus and using it in the field, well done to Quyen and Kurt.

Thanks guys.

Color balance was for my redheads. Which should be 3200K, right? Although I ran in to some problems. As you have probably noticed it's recorded in my livingroom. So I got all sort of color casts, for example the red carpet on the floor mixing with the blueisch paper on which the test chart is printed. And my walls are light yellow. All this makes an even white hell, especially if your test chart is 1,5 m wide. The living room lamp obviously had a different temperature (it's one of those 'saving lamps', I don't really know the English word for that). I don't know the color temperature of a black light. But I know I won't be using them anymore. At least, not as long as I'm stuck with 4:1:1 color compression.

About chromatic aberration. It's just a feeling, but only the blue really bothers me.

If some of the sound are forbidden, I think I go to the wrong places, because I think you are talking about the field recordings.

What a superb test! . .and very amusing too! - Grazie

I was joking! I wanted to make a post that would not give away your surprise video. It is definitely the most exciting test chart video I have ever seen. I guessed that the sound you used was from the sound track of the movie "Forbidden Planet" and I used the word "forbidden" to hint that I thought you used that for sound.

I suggest everyone that has or wants to own a 35mm adapter download and watch this video.

For the blacklight, I don't think that's chromatic aberration from the Letus35. The very high frequencies of light are difficult for anything to focus, even the human eye. It is also probably a challenge for your camera's CCDs to properly register that UV color. As for chromati aberration under normal light, I don't think it is very bad. If the colors are off, the white balance seems to have corrected things. Do your colors look very different if you shoot wihout the Letus35?

Marcus,

The letus has absolutely no trouble with blacklight. 4:1:1 DV Compression has. Since the image is strong blue only, compression blocks were about the size of crossword puzzle squares. So I decided to put a blur on the blue channel. Rather blur than blocks. But really, it's merely the camera. The faults of the Letus can be seen in the blacks surrounding the test chart.

About how the Letus changes colors, it doesn't really change the colors but it changes the curves, which become a bit more natural, more as I perceive them in real life, ending up in enjoyment during filming. One downside seems to be a very soft grayisch tone over the image. Sometimes.

About the forbidden planet, sorry, I just didn't got it. I only saw it once long ago. I made the sounds myself, but they are indeed very retro.

Many thanks for the comments. They really make recovering from the worst cold I've ever had a lot more fun.