Jump to content


Photo

The Brevis 35mm adapter


  • Please log in to reply
7 replies to this topic

#1 stevewitt

stevewitt
  • Basic Members
  • PipPip
  • 31 posts
  • Student

Posted 15 April 2007 - 10:16 PM

Has anyone on here had the chance to play around with the Brevis 35mm adapter made by Cinevate? I just ordered one and I can't wait. All of the sample footage I have seen made with this adapter looks pretty good. :)
  • 0

#2 Brant Collins

Brant Collins
  • Basic Members
  • PipPipPip
  • 165 posts
  • Producer
  • Little Rock, Arkansas

Posted 05 August 2007 - 08:01 PM

did you get it yet. I think it is the one I want. Just wanted to know how you liked yours?
  • 0

#3 Jamie Metzger

Jamie Metzger
  • Basic Members
  • PipPipPipPip
  • 773 posts
  • Cinematographer
  • San Francisco

Posted 06 August 2007 - 03:33 AM

Hey, I feel like I am the guy that will turn you away from the brevice.

The only reason we are using one on my current production is to save weight for the steadycam.

The brevice that we got was a huge piece of garbage. Right now it's got a mixture of ace hardware screws and super glue holding it together. It's quite scary. We are getting good images out of it, but it's not worth the worry, and effort we have put into it.

The guy building the piece obviously doesn't know too much about the gear that attaches to lenses, or about lenses in general. A lot of lenses loose focus around the edge of the frame, and that's if they aren't vignetting!

Always remember to turn it on as well.

Also, using longer lenses, like a 50mm, or 85 (my favorite for closeups) looks great, but wider lenses like a 25mm or 18 still look good but the shallow depth of field isn't there as much, which throws you off.

Don't plan any big productions until you get very desireable results with the brevice and you truly trust it.

Also, never use gain with a 35mm adapter.

Jamie
  • 0

#4 Satsuki Murashige

Satsuki Murashige
  • Sustaining Members
  • 3510 posts
  • Cinematographer
  • San Francisco, CA

Posted 07 August 2007 - 03:37 AM

Well, I'm going to have to disagree with Jaime.

I've just pulled focus on two Brevis shoots back-to-back, and the Brevis itself performed fine. There's no doubt it's a limited system, but you shouldn't see soft corners or vignetting if the camera lens is zoomed in enough. I think what throws people is mainly the rod system that comes with the adapter -- frankly, it's not very good and non-standard to boot, so you'll have problems getting your matte box to stay on, etc. Also, it's supposed to be tool-less, but you need the allen keys to adjust all the fittings, so that's slows things down a bit.

You have to collimate the adapter properly and test all you lenses with the system. I've found that many of the wider Nikons beyond 28mm will exhibit portholing (different from vignetting -- bright center spot, dimmer corners, but not black corners), which gets worse as you stop down. 28mm is still pretty wide though (think 35mm stills field-of-view, not 35mm motion picture), far wider than most stock DV lenses. Plus the wide angle lenses are generally rectilinear, so you won't get the barrel distortion that you'd normally find with wide angle adapters/converters. The best stops to work at are invariably from f2.8-4. You can generally go down to f5.6, but anymore than that reveals the groundglass pattern.

Light loss is minimal. Make sure you have a set of glass ND filters. You don't want to use the internal NDs if at all possible because you'll be overexposing the image at the ground glass, which is in front of camera's internal filters. Similarly, you don't want to stop down the internal iris much beyond f4, if that.

Once the backfocus (camera lens focus ring and zoom) is set, write down the numbers and tape the rings down. Check them religiously. Try not to break the camera down once it's been built up. One of the DPs who owned his own rig had a huge Pelican case with the foam cut so that the whole rig could be put away intact -- DVX, Brevis, baseplate, rods, matte box, handles, on-board monitor mount, custom rear-mounted breakout box, and shoulder mount -- whew! Wish I had a picture of that beast!

I don't know if it's possible to collimate the Nikons to the Brevis mount so that their focus scales will be accurate. I never managed to get accurate scales on either shoot, so having a monitor nearby to check eye-focus and pull focus from is a must. The bigger and sharper the monitor the better. I've found cheap onboard LCDs (like the Marshall 8") to be almost worthless in this regard. One of the shoots was with an HVX, and without the 17" Panasonic on set, finding critical focus was almost impossible -- without accurate lens scales, there's no reference for the focus puller besides eye focus. Conversely, I found that using a CRT monitor (like a cheap TV) makes the footage look sharper than the image really is, which can be dangerous when focus is so critical. Plus, they start acting funny when you flip them upside down!

The on-board monitor is a must for framing though, since your image will be flipped. Most small LCDs should have mounting points on both the bottom and the top, so you can just mount the monitor upside down to the hot shoe via a pivoting mount of some sort. Just be careful to save your monitor batteries (and have lots of spares) because they'll get used up real quick. Turn the monitor off between takes and use AC power when you can. I've found the Brevis itself to be a pleasant surprise in this regard -- its battery lasts a long time, and it recharges in about 20 minutes. Always check to make sure it's on before shooting though. When you hear, "Roll sound, roll camera" think "BREVIS ON!"

Hope this was helpful to you.:)
  • 0

#5 Ash Greyson

Ash Greyson
  • Basic Members
  • PipPip
  • 28 posts
  • Director
  • Tulsa, OK

Posted 07 August 2007 - 09:52 AM

Hey, I feel like I am the guy that will turn you away from the brevice.

The only reason we are using one on my current production is to save weight for the steadycam.

The brevice that we got was a huge piece of garbage. Right now it's got a mixture of ace hardware screws and super glue holding it together. It's quite scary. We are getting good images out of it, but it's not worth the worry, and effort we have put into it.

The guy building the piece obviously doesn't know too much about the gear that attaches to lenses, or about lenses in general. A lot of lenses loose focus around the edge of the frame, and that's if they aren't vignetting!

Always remember to turn it on as well.

Also, using longer lenses, like a 50mm, or 85 (my favorite for closeups) looks great, but wider lenses like a 25mm or 18 still look good but the shallow depth of field isn't there as much, which throws you off.

Don't plan any big productions until you get very desireable results with the brevice and you truly trust it.

Also, never use gain with a 35mm adapter.

Jamie




A mountain of misinformation here. I have used a Brevis, after testing every sub $2000 adapter EXTENSIVELY, for about 6 months. The FD mount, currently being improved, works but is not real solid but other than that, it is built quite well. If you are losing focus on the edges it is either off center camera optics or user error. Both can be corrected.

I really wish people would stop blaming their gear for their lack of operational experience.




ash =o)
  • 0

#6 Michael Nash

Michael Nash
  • Sustaining Members
  • 3330 posts
  • Cinematographer
  • Pasadena, CA

Posted 14 August 2007 - 01:34 AM

Once the backfocus (camera lens focus ring and zoom) is set, write down the numbers and tape the rings down. Check them religiously.


Just to clarify, taping the DVX focus ring is a temporary measure at best. The DVX & HVX focus rings are not mechanically linked, and instead use servo motors. So even if your focus ring is taped in place, the backfocus can and will drift. For best performance you have to check it before every setup.

Reason #837 to hate these adapters...
  • 0

#7 Satsuki Murashige

Satsuki Murashige
  • Sustaining Members
  • 3510 posts
  • Cinematographer
  • San Francisco, CA

Posted 15 August 2007 - 05:30 AM

Just to clarify, taping the DVX focus ring is a temporary measure at best. The DVX & HVX focus rings are not mechanically linked, and instead use servo motors. So even if your focus ring is taped in place, the backfocus can and will drift. For best performance you have to check it before every setup.

Reason #837 to hate these adapters...

All true of course, but it's not as inconvenient as all that, just a quick glance at the camera's LCD will tell you if your "Z" and "F" numbers have shifted. It hasn't happened to me very often, even on very bumpy car mount shots.

Sure, it's not as nice as a film camera with a rock-solid PL mount, but when I pull focus on film shoots, I check the T-stop and focus on the lens before every take too, so not much has changed -- now I just have to do it twice! Of course, if you're shooting without an AC, then it's one more variable that the DP has to juggle. Now that I'll admit, can get old real fast.
  • 0

#8 Andrew Nicholson

Andrew Nicholson

    New

  • Basic Members
  • Pip
  • 7 posts
  • Camera Operator

Posted 21 October 2007 - 09:39 AM

The only way to go is with the Letus Extreme. It beats all other adapters in its range and even out does the P&S Technik with only a half stop of light loss even with the built in flip. The Nikon attachment makes for prime image production and gives the most beautyful bokeh and stunningly sharp images without vignetting. The Extreme truly is an adapter in it's own league. Damn, makes me wanna buy another one after writing that!!!
  • 0


Visual Products

Media Blackout - Custom Cables and AKS

The Slider

Ritter Battery

Metropolis Post

CineLab

Rig Wheels Passport

Gamma Ray Digital Inc

Broadcast Solutions Inc

Tai Audio

Glidecam

rebotnix Technologies

Opal

Aerial Filmworks

Paralinx LLC

FJS International, LLC

CineTape

Willys Widgets

Abel Cine

Wooden Camera

Technodolly

Visual Products

Tai Audio

Ritter Battery

Gamma Ray Digital Inc

Wooden Camera

Glidecam

Technodolly

CineLab

Aerial Filmworks

Broadcast Solutions Inc

Rig Wheels Passport

CineTape

Paralinx LLC

Abel Cine

Willys Widgets

Media Blackout - Custom Cables and AKS

The Slider

Metropolis Post

FJS International, LLC

rebotnix Technologies

Opal