Cinevate Brevis, cfXL & EX1
Firstly, let me begin by saying that this is not a full review of the Cinevate Brevis 35mm adapter, there are loads of good descriptions of the unit and how it works on the web so you should easily be able to find one of those. This report focuses on using the brevis with a Sony EX1.
In most respects the Brevis is a great device, highly adjustable and works well. That being said though I don’t feel it’s fully compatible with my current camera, the Sony EX1. I purchased my brevis with the cf XL diffuser which Cinevate claim as being “designed to address the Sony EX1 optical issues”.
That statement is quite an interesting one and after some communication with Cinevate it’s apparent that they feel there are problems with the lens on the EX1, even though these problems don’t effect the use of the EX1 by itself.
If you look at any of the videos I’ve shot with the brevis and EX1 you’ll see that a lot of the footage is suffering from dark edges on the left and right sides of frame. For me this is the biggest problem when trying to pair the Brevis with an EX1. There are also edge to edge sharpness issues which I’ll go into later.
These dark edges or vignetting issues are quite apparent in my video “Morston Mud” and can bee seen on the video thumbnail before the video starts playing where the large boat is laying on the beach. Shots with lots of light suffer less, but in lower light conditions the problem can be a lot worse.
Cinevate, the makers of the Brevis are very helpful and one of the best companies I have dealt with in terms of customer service and response times. Cinevate seem to be fully aware that pairing the Brevis with the EX1 can be a bit tricky and although they claim the cfXL diffuser corrects some EX1 problems they openly admit that the EX1 is not as ‘Brevis Friendly’ as Canon’s XH-A1 or Panasonics HVX200 / 201.
Apparently the lens on the EX1 has proven to be problematic for most 35mm adapters, I’m not entirely sure of the technical reasons for this but both Letus and Shoot35 have also had problems adapting their products to work well with it. Letus released a custom achromat for their ‘Extreme’ adapter which is very popular amongst EX1 owners. Unlike Letus though, Cinevate have not taken the route of producing a custom EX1 achromat and instead have produced the custom cfXL diffuser.
I have to be honest and say that as much as I love the bokeh and the look of the Brevis for my personal videos, I would be very nervous about using it for a commercial project with my EX1.
The only other issue I’ve had so far is that dust seems to get into the unit very easily. I have tried to combat this by taping up all of the exposed gaps using insulation tape, which although not pretty does seem to help.
If you own an EX1 or EX3 I would advise against purchasing a Brevis adapter at this time. I have heard from four other EX1 & Brevis owners who suffer the same problems I do and nobody who says they have the same combination without issues.
In general the Brevis is well made, for XH-A1 or HVX owners I would highly recommend it for it’s adjustability and use of good quality materials, but for the EX1 it just doesn’t work well enough.
[update - 31/10/2008]
I’ve been doing some expirements with zooming further in today and the one thing I’ve come to realise with the Brevis is that by changing the zoom you’re fighting against two separate side effects. At wider zooms (z70) it’s possible to get almost perfect edge to edge sharpness, which is the reason why Dennis from Cinevate recommended that setting, but this problem with the dark edges is more apparent at that setting and is a separate issue. By zooming past these dark edges to around z80 the edge to edge sharpness starts to suffer and anything further than z80 results in the focused area being confined more and more to the centre of the image.
[update - 5/11/2008]
After shooting at Z80 for a while my feelings are that it still doesn’t result in good footage, the vignetting is still apparent in many shots, and especially when shooting in low light. Edge to edge sharpness is also badly effected at z80.
The only way I have been able to get usable footage is by shooting with the EX1 zoomed out to z60 and then cropping the footage in post. You lose resolution using this method though so although good for web video or 720p you cannot achieve true 1080p results.