Brevis35 - Optional GG Footage

Dennis Wood · August 16th, 2006, 10:08 AM

Steve, based on your posts of late, you'll become intimately familiar with the term bokeh in very short order. You'd be surprised at how many folks in the industry haven't heard that term before. It's a bit of an obsession in the 35mm adapter world :-)

Steve Witt · August 16th, 2006, 10:45 AM

Hey Dennis,
My wife is working on her PHD and I can't wait to use this word in front of her.

I have also become very familiar with the GS400 footage from your adapter and I like what I see. I will very much consider purchasing your adapter in the future, but it seems like the intitiation into the adapter world is to build your own first. I'm gonna try the rotating CD(GG) first so I can say "been there done that". What is your favorite 35mm lens to use with your Brevis35 adapter and GS400 combo?

Frank Hool · August 16th, 2006, 11:41 AM

Steve, here's my earlier post about bokeh with link to best explanation imo.

Dennis Wood · August 16th, 2006, 02:49 PM

I built a few spinners first too....pmail if you need some stuff. You can likely build yourself a very good adapter providing you're willing to play a bit :-)

If you are looking for lenses, a 50mm f1.4 or f1.2 should be your first. I also frequently use an f2.8 28-70 zoom. A stable of primes would be better, but the f2.8 zoom is very versatile. Light loss, a spinner, and the GS400 will predicate the fastest lenses you can find.

Steve Witt · August 16th, 2006, 02:57 PM

Thanks Dennis. I pretty much have what I need for the spinner(I think), except the Lens itself. Did you use a "macro" with your spinner or just let the GS400 do its own macro thing?

Frank Hool, Thankyou for the link to your explanation post.

Dennis Wood · August 16th, 2006, 04:56 PM

Steve, if you're going for a standard spinner you'll need a condenser and an achromat. If you search here for the terms, you'll find plenty of info on what works, and where to get them. I've yet to see a spinner that did not require an achromat to properly frame the GG. With the Brevis design, no achromat is required for smaller cams like the GS400, due to the adapter's large usable frame size.

The GS400 macro is useless to you as it will force 12X zoom, allowing you to focus on objects ~3 feet or more away..but no closer.

Steve Witt · August 19th, 2006, 10:01 AM

Hey Dennis,
The condenser that you mentioned above for the spinners......is this something that go's between the camcorder and the adapter, or between the 35mm lens and the adapter?

Also, I have bid on a 35mm canon FD 1.4 SSC manual lens on Ebay. If I win it will be about $20 with the shipping. Anyhow, I wasn't sure what the S.S.C. stood for and was looking for a little help here also.

Thanks for everything.

Dennis Wood · August 20th, 2006, 04:12 PM

Steve, there's setups with before, after and both. You need to experiment a bit with your setup.

Steve Witt · September 4th, 2006, 11:19 AM

Hey Dennis,
I've read on these Condensers (plano-convex type) for cd blank spinning adapters. Are there lenses like this that come with the "threads" (like filters, attachments, etc)that we can use with our camcorders and lenses? My searches on this are only coming up with a lense with no rim or threads. Just a piece of glass/plastic. If this is what everyone is using...how do you attatch it to your assembly?

Can anyone help? Thanks.

Giroud Francois · September 4th, 2006, 12:06 PM

just for your info.
i purchased recently a letus35a for some test.
i took it from the "Handyman corner" so price is lower.
the goal is to test all the ways it could be enhanced in order to get a really good picture for a FX1, without the hassle of dealing with basic mechanic.
I will remove all useless glass (front window), widen the gg window, change the lenses, build a better GG.
For the GG glass , i selected ultra thin glass (0.2mm and .5mm thick) from Schott glass.
I will use 1500 grit al. oxyde as per my previous static GG.
They sell the glass (AF45 quality, the best for optical use) in set of 3 sheets of 100 by 100 mm for about 130$.
since it is a lot more than i need, if somebody is interested, i hope to be able to cute more than one GG.
obviously it is for use on vibrating gg, not rotating.

Dennis Wood · September 11th, 2006, 09:36 PM

Ok, here's some of that famous garden footage done at dusk with the Brevis optional diffuser. This version is the production element. It's shot with a Minolta Rokkor 50mm f1.4, set at f2.8. A little GS400 shooting 16:9 procinema (frame mode) was perched at the other end. I had the rig on a stabilizer, but obviously need more practice...a lot more. Check the crispy bokeh at time 1:20.

43MB WMV, Fast
43MB WMV, Alternate

Jim Lafferty · September 11th, 2006, 11:09 PM

Looks great. Any difference in light loss between the two diffusers, Dennis?

Dennis Wood · September 12th, 2006, 06:16 AM

Jim, I haven't properly quantified it yet, however the value will be close to .4 stops or so. The adapter "total system loss" with a 50mm f1.4 attached and using the diffusor option will be just under 1 stop...or basically the light loss attributable to the 35mm lens. My holy grail, other than keeping light loss low, and visible grain 0, is to get proper rendition of specular highlights in out of focus areas, that are free of halation during focus racks. This is as close to perfect film emulation as I can imagine. This GG also has a usable "grain free" f range well into the f4 area.

I have two other diffusion options on tap, but these have too much grain, (I'm pretty sure anyway) to work well with our incoming OCT19 cinema lenses.

David Delaney · September 12th, 2006, 12:30 PM

Giroud,

Let me know how the Letus35A mod turns out, I might want to try that as well.

Phil Bloom · October 29th, 2006, 10:44 AM

Quote:

Originally Posted by Giroud Francois

just for your info.
i purchased recently a letus35a for some test.
i took it from the "Handyman corner" so price is lower.
the goal is to test all the ways it could be enhanced in order to get a really good picture for a FX1, without the hassle of dealing with basic mechanic.
I will remove all useless glass (front window), widen the gg window, change the lenses, build a better GG.
For the GG glass , i selected ultra thin glass (0.2mm and .5mm thick) from Schott glass.
I will use 1500 grit al. oxyde as per my previous static GG.
They sell the glass (AF45 quality, the best for optical use) in set of 3 sheets of 100 by 100 mm for about 130$.
since it is a lot more than i need, if somebody is interested, i hope to be able to cute more than one GG.
obviously it is for use on vibrating gg, not rotating.

How did you get on with the mod?

August 16th, 2006, 11:41 AM	#18
Frank Hool Major Player Join Date: Apr 2006 Location: Barca Spain Posts: 384	bokeh Steve, here's my earlier post about bokeh with link to best explanation imo.

August 19th, 2006, 10:01 AM	#22
Steve Witt Major Player Join Date: Feb 2005 Location: kentucky, USA Posts: 429	Still learning Hey Dennis, The condenser that you mentioned above for the spinners......is this something that go's between the camcorder and the adapter, or between the 35mm lens and the adapter? Also, I have bid on a 35mm canon FD 1.4 SSC manual lens on Ebay. If I win it will be about $20 with the shipping. Anyhow, I wasn't sure what the S.S.C. stood for and was looking for a little help here also. Thanks for everything.

September 11th, 2006, 11:09 PM	#27
Jim Lafferty Major Player Join Date: Dec 2003 Location: Brooklyn, NY Posts: 636	Looks great. Any difference in light loss between the two diffusers, Dennis? __________________ Realism, anyway, is never exactly the same as reality, and in the cinema it is of necessity faked. -- J-L G

August 16th, 2006, 10:08 AM	#16
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	Steve, based on your posts of late, you'll become intimately familiar with the term bokeh in very short order. You'd be surprised at how many folks in the industry haven't heard that term before. It's a bit of an obsession in the 35mm adapter world :-)

August 16th, 2006, 10:45 AM	#17
Steve Witt Major Player Join Date: Feb 2005 Location: kentucky, USA Posts: 429	Hey Dennis, My wife is working on her PHD and I can't wait to use this word in front of her. I have also become very familiar with the GS400 footage from your adapter and I like what I see. I will very much consider purchasing your adapter in the future, but it seems like the intitiation into the adapter world is to build your own first. I'm gonna try the rotating CD(GG) first so I can say "been there done that". What is your favorite 35mm lens to use with your Brevis35 adapter and GS400 combo?

August 16th, 2006, 02:49 PM	#19
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	I built a few spinners first too....pmail if you need some stuff. You can likely build yourself a very good adapter providing you're willing to play a bit :-) If you are looking for lenses, a 50mm f1.4 or f1.2 should be your first. I also frequently use an f2.8 28-70 zoom. A stable of primes would be better, but the f2.8 zoom is very versatile. Light loss, a spinner, and the GS400 will predicate the fastest lenses you can find.

August 16th, 2006, 02:57 PM	#20
Steve Witt Major Player Join Date: Feb 2005 Location: kentucky, USA Posts: 429	Thanks Dennis. I pretty much have what I need for the spinner(I think), except the Lens itself. Did you use a "macro" with your spinner or just let the GS400 do its own macro thing? Frank Hool, Thankyou for the link to your explanation post.

August 16th, 2006, 04:56 PM	#21
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	Steve, if you're going for a standard spinner you'll need a condenser and an achromat. If you search here for the terms, you'll find plenty of info on what works, and where to get them. I've yet to see a spinner that did not require an achromat to properly frame the GG. With the Brevis design, no achromat is required for smaller cams like the GS400, due to the adapter's large usable frame size. The GS400 macro is useless to you as it will force 12X zoom, allowing you to focus on objects ~3 feet or more away..but no closer.

August 20th, 2006, 04:12 PM	#23
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	Steve, there's setups with before, after and both. You need to experiment a bit with your setup.

September 4th, 2006, 11:19 AM	#24
Steve Witt Major Player Join Date: Feb 2005 Location: kentucky, USA Posts: 429	Hey Dennis, I've read on these Condensers (plano-convex type) for cd blank spinning adapters. Are there lenses like this that come with the "threads" (like filters, attachments, etc)that we can use with our camcorders and lenses? My searches on this are only coming up with a lense with no rim or threads. Just a piece of glass/plastic. If this is what everyone is using...how do you attatch it to your assembly? Can anyone help? Thanks.

September 4th, 2006, 12:06 PM	#25
Giroud Francois Inner Circle Join Date: Feb 2004 Location: switzerland Posts: 2,133	just for your info. i purchased recently a letus35a for some test. i took it from the "Handyman corner" so price is lower. the goal is to test all the ways it could be enhanced in order to get a really good picture for a FX1, without the hassle of dealing with basic mechanic. I will remove all useless glass (front window), widen the gg window, change the lenses, build a better GG. For the GG glass , i selected ultra thin glass (0.2mm and .5mm thick) from Schott glass. I will use 1500 grit al. oxyde as per my previous static GG. They sell the glass (AF45 quality, the best for optical use) in set of 3 sheets of 100 by 100 mm for about 130$. since it is a lot more than i need, if somebody is interested, i hope to be able to cute more than one GG. obviously it is for use on vibrating gg, not rotating.

September 11th, 2006, 09:36 PM	#26
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	Ok, here's some of that famous garden footage done at dusk with the Brevis optional diffuser. This version is the production element. It's shot with a Minolta Rokkor 50mm f1.4, set at f2.8. A little GS400 shooting 16:9 procinema (frame mode) was perched at the other end. I had the rig on a stabilizer, but obviously need more practice...a lot more. Check the crispy bokeh at time 1:20. 43MB WMV, Fast 43MB WMV, Alternate

September 12th, 2006, 06:16 AM	#28
Dennis Wood Major Player Join Date: Mar 2005 Location: Ontario, Canada Posts: 916	Jim, I haven't properly quantified it yet, however the value will be close to .4 stops or so. The adapter "total system loss" with a 50mm f1.4 attached and using the diffusor option will be just under 1 stop...or basically the light loss attributable to the 35mm lens. My holy grail, other than keeping light loss low, and visible grain 0, is to get proper rendition of specular highlights in out of focus areas, that are free of halation during focus racks. This is as close to perfect film emulation as I can imagine. This GG also has a usable "grain free" f range well into the f4 area. I have two other diffusion options on tap, but these have too much grain, (I'm pretty sure anyway) to work well with our incoming OCT19 cinema lenses.

September 12th, 2006, 12:30 PM	#29
David Delaney Trustee Join Date: Feb 2006 Location: Niagara Ontario Canada Posts: 1,121	Giroud, Let me know how the Letus35A mod turns out, I might want to try that as well.