The Letus35 Redesigned :)

Ben Winter · January 27th, 2006, 04:35 PM

Yes. I guess that makes it the the macro.

Wayne Kinney · January 27th, 2006, 04:43 PM

So your saying you had the distortion before and after the century optics macro?

Ben Winter · January 27th, 2006, 05:04 PM

Well the PCX on the letus mostly cancelled it out, but depending on the distance it would get better or worse.

Jim Lafferty · January 29th, 2006, 11:04 AM

Where is everyone getting their 120mm PCX lenses from these days?

Jim Lafferty · February 1st, 2006, 08:52 AM

BTW -- if someone wants a Beattie screen (the smaller one, clear matte finish for the Contax), let me know. I've got an entirely unused screen here I just bought from B&H and have decided to use something else. Cost to me was $93 plus shipping, so I'd sell it for the same to anyone interested. Ordering it from B&H took a while -- I'd send it off w/in one day of ordering.

Dennis Wood · February 1st, 2006, 10:12 AM

consider it sold....pmail me.

Jim Lafferty · February 1st, 2006, 06:03 PM

consider you pmailed.

Aaron McMath · February 3rd, 2006, 01:32 AM

Any new developments Ben? Seems like maybe you ran into trouble. I ordered a beattie screen, and also pre-ordered G35. I want to buy the high-lux version, so I'm hoping that the Letus can serve as my low-lux with the beattie installed. So I'm curious to see how it's going for you. Have you had to clean the beattie yet?

Daniel Apollon · February 3rd, 2006, 07:17 AM

I would suggest the following test:

TEST I

1) Before changing the Letus' focusing screen to the Intenscreen, shoot a good color chart with the original Letus GG and a line and pattern chart taking care not to pass the upper 80 IRE limit. Note the f value of the 35mm objective and the f value of the camera objective (e.g. objective).

Keep track of distance and angles and magnification, in order to ensure quasi-identical pictures.

2) After installing the Beattie Intenscreen repeat the same operation, conforming to the same upper 80 IRE limit.

Post the results as TIFF pictures (no further compression !).

TEST II

Create shooting conditions allowing to evaluate bokeh, CA and other artefacts.

Post the results.

Until then, the superiority of the Beattie solution remains an unsubstantiated claim.

Ben Winter · February 3rd, 2006, 01:23 PM

Hey guys, sorry I haven't posted here in a while, I've been busy with a TV project that's due Tuesday--and we haven't even finished filming yet. So I apologize if I seem a little busy, because I am.

Daniel, I agree with the degree of thoroughness that you're demanding but you're not going to get those tests from me, sorry. I'm simply not willing to switch out my GG again after putting in the Beattie which was, I must say, a trying exercise. If Quyen's willing to ship me another vibration unit maybe I'd reconsider.

And unsubstantiated? Any fellow Letus owner would agree that the results I've posted are much sharper than that of the stock GG.

I do understand the strength of your curiousity but I'm sorry that I'm not able to satisfy it.

I will post res charts with the Beattie screen and more tests soon, after this nightmare of a project wraps up.

Daniel Apollon · February 3rd, 2006, 01:42 PM

Ben, I did not meant to say that your claims were unsubstantiated. Actually, the Beattie ground glass appears to be substantially better in term of (1) clarity, (2) sharpness. However, final judgement must be postponed until comparative tests taking into consideration all relevant parameters which constitute overall optical quality have been carried out .
It would much easier for people such as Quyen, the "Father" of the Letus35 to carry out such tests. I own a Letus35A Flip and I'm wondering whether Quyen has improved the GG in this version.

Dennis Wood · February 3rd, 2006, 05:34 PM

Daniel, being that you already have a letus flip, and you have a detailed methodology worked out....why not spend the $92, grab a beattie, and post em up? My thinking is that a random holographic diffussion surface combined with a light directing fresnel, and Dan D's exhaustive tests, would indicate that Ben's results are indeed valid.

From what I've seen of letus footage, I would theorize that the squirmy grain I pointed out is DV compression's response to low frequency vibrating GG's...regardless of surface.

Ben, those EIA1956 with and without your adapter would be easy though.....Steve Dinkins? MPIC test? Now if I could just find Jim with that beattie he's selling.....

Daniel Apollon · February 4th, 2006, 03:16 AM

Quote:

Originally Posted by Dennis Wood

From what I've seen of letus footage, I would theorize that the squirmy grain I pointed out is DV compression's response to low frequency vibrating GG's...regardless of surface.≈.

Dennis, this sound interesting and potentially important, could you elaborate on this point (compression response) ? Thanks.

Another issue, which needs to be tested, and is potentially much more complicated, is evaluating the diffusion/spread pattern of colours through the focusing screen. And I'm not referring to "aberrations" or "artefacts" but to "the spatial interpretation of the color spectrum/colour space". As most of us have noticed, the overall colorimetry of a picture shot on a focusing screen afffected. Additionally, any filmmaker will develop a subjective experience of the "distinctive colouring" of the picture generated but any 35mm adapter. E.g., using the Letus35A Flip on a DVX100A with original Canon optics and shooting progressive, I get a much more saturated, more 16mm-like colouring. It's not a problem or a deficiency, just a characteristic of my adapter.

Jim Lafferty · February 6th, 2006, 12:36 PM

Well said, Daniel.

Daniel Rudd · February 6th, 2006, 12:43 PM

Quote:

Originally Posted by Ben Winter

Don't forget that the G35 is built to be much more durable than the Letus, as well as the fact that the G35 is apparently static...but then again, is it worth the extra $$$?

Actually, I just read in their FAQ that they will no longer be making the g35 static. Something to do with the requirements of HD cameras.

Suddenly, I'm much less excited about the G35

January 27th, 2006, 04:35 PM	#106
Ben Winter Trustee Join Date: Jun 2005 Location: Hollywood, CA Posts: 1,675 Images: 1	Yes. I guess that makes it the the macro. __________________ BenWinter.com

January 27th, 2006, 04:43 PM	#107
Wayne Kinney Major Player Join Date: Jun 2005 Location: Brighton, East Sussex, UK Posts: 938	So your saying you had the distortion before and after the century optics macro? __________________ Thanks, Wayne.

January 27th, 2006, 05:04 PM	#108
Ben Winter Trustee Join Date: Jun 2005 Location: Hollywood, CA Posts: 1,675 Images: 1	Well the PCX on the letus mostly cancelled it out, but depending on the distance it would get better or worse. __________________ BenWinter.com

January 29th, 2006, 11:04 AM	#109
Jim Lafferty Major Player Join Date: Dec 2003 Location: Brooklyn, NY Posts: 636	Where is everyone getting their 120mm PCX lenses from these days? __________________ Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G

February 1st, 2006, 08:52 AM	#110
Jim Lafferty Major Player Join Date: Dec 2003 Location: Brooklyn, NY Posts: 636	BTW -- if someone wants a Beattie screen (the smaller one, clear matte finish for the Contax), let me know. I've got an entirely unused screen here I just bought from B&H and have decided to use something else. Cost to me was $93 plus shipping, so I'd sell it for the same to anyone interested. Ordering it from B&H took a while -- I'd send it off w/in one day of ordering. __________________ Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G

February 1st, 2006, 10:12 AM	#111
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	consider it sold....pmail me.

February 1st, 2006, 06:03 PM	#112
Jim Lafferty Major Player Join Date: Dec 2003 Location: Brooklyn, NY Posts: 636	consider you pmailed. __________________ Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G

February 3rd, 2006, 01:32 AM	#113
Aaron McMath New Boot Join Date: Sep 2005 Posts: 15	Any new developments Ben? Seems like maybe you ran into trouble. I ordered a beattie screen, and also pre-ordered G35. I want to buy the high-lux version, so I'm hoping that the Letus can serve as my low-lux with the beattie installed. So I'm curious to see how it's going for you. Have you had to clean the beattie yet?

February 3rd, 2006, 07:17 AM	#114
Daniel Apollon Regular Crew Join Date: Oct 2005 Location: Norway & France Posts: 50	Testing the Beattie Intenscreen on the Letus35 I would suggest the following test: TEST I 1) Before changing the Letus' focusing screen to the Intenscreen, shoot a good color chart with the original Letus GG and a line and pattern chart taking care not to pass the upper 80 IRE limit. Note the f value of the 35mm objective and the f value of the camera objective (e.g. objective). Keep track of distance and angles and magnification, in order to ensure quasi-identical pictures. 2) After installing the Beattie Intenscreen repeat the same operation, conforming to the same upper 80 IRE limit. Post the results as TIFF pictures (no further compression !). TEST II Create shooting conditions allowing to evaluate bokeh, CA and other artefacts. Post the results. Until then, the superiority of the Beattie solution remains an unsubstantiated claim. Last edited by Daniel Apollon; February 3rd, 2006 at 09:48 AM.

February 3rd, 2006, 01:23 PM	#115
Ben Winter Trustee Join Date: Jun 2005 Location: Hollywood, CA Posts: 1,675 Images: 1	Hey guys, sorry I haven't posted here in a while, I've been busy with a TV project that's due Tuesday--and we haven't even finished filming yet. So I apologize if I seem a little busy, because I am. Daniel, I agree with the degree of thoroughness that you're demanding but you're not going to get those tests from me, sorry. I'm simply not willing to switch out my GG again after putting in the Beattie which was, I must say, a trying exercise. If Quyen's willing to ship me another vibration unit maybe I'd reconsider. And unsubstantiated? Any fellow Letus owner would agree that the results I've posted are much sharper than that of the stock GG. I do understand the strength of your curiousity but I'm sorry that I'm not able to satisfy it. I will post res charts with the Beattie screen and more tests soon, after this nightmare of a project wraps up. __________________ BenWinter.com

February 3rd, 2006, 01:42 PM	#116
Daniel Apollon Regular Crew Join Date: Oct 2005 Location: Norway & France Posts: 50	Testing again Ben, I did not meant to say that your claims were unsubstantiated. Actually, the Beattie ground glass appears to be substantially better in term of (1) clarity, (2) sharpness. However, final judgement must be postponed until comparative tests taking into consideration all relevant parameters which constitute overall optical quality have been carried out . It would much easier for people such as Quyen, the "Father" of the Letus35 to carry out such tests. I own a Letus35A Flip and I'm wondering whether Quyen has improved the GG in this version.

February 3rd, 2006, 05:34 PM	#117
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	Daniel, being that you already have a letus flip, and you have a detailed methodology worked out....why not spend the $92, grab a beattie, and post em up? My thinking is that a random holographic diffussion surface combined with a light directing fresnel, and Dan D's exhaustive tests, would indicate that Ben's results are indeed valid. From what I've seen of letus footage, I would theorize that the squirmy grain I pointed out is DV compression's response to low frequency vibrating GG's...regardless of surface. Ben, those EIA1956 with and without your adapter would be easy though.....Steve Dinkins? MPIC test? Now if I could just find Jim with that beattie he's selling.....

February 6th, 2006, 12:36 PM	#119
Jim Lafferty Major Player Join Date: Dec 2003 Location: Brooklyn, NY Posts: 636	Well said, Daniel. __________________ Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G