RedRock M2 versus Cinevate Brevis : A Review...
- Thread starter rgdfilms
- Start date
rgdfilms
Wet poodle
Shot this video last night, here is an example of the vibration noise with the Brevis - my audio levels are in the mid-range on the HVX in this clip, camera pointed down. A lot of those higher frequencies you are hearing are actually from the 28mm Nikkor, lower frequencies are the coming out of the Brevis. I have been holding my hand over the Brevis while shooting and that seems to help. I think a cloth washcloth would help as well.. I am going to play more with it.
http://www.richard-darge.com/HD/vibrationnoise.mov
this clip came from this piece if you are bored..
http://www.richard-darge.com/HD/hairbrush.mov
http://www.richard-darge.com/HD/vibrationnoise.mov
this clip came from this piece if you are bored..
http://www.richard-darge.com/HD/hairbrush.mov
Dennis Wood
DVXuser Sponsor
Richard, that hair brush clip needs a bald guy at the end (I'm uniquely qualified to comment) shrieking and holding his head 
Mr. Hitchcock would be proud.
Mr. Hitchcock would be proud.Nice post rgd, things are getting clearer. A couple of questions for you and Dennis...
1) The M2 is vignetting in your tests...I'm guessing your point is to show the usable frame with each adapter? If so, that's quite a difference. Correct me if I'm wrong - using a 24mm lens on the M2 might offer the same fov as a 28mm on the Brevis, for eg?
2) The light loss between the adapters seems significant. How many stops would you say? Edit - based on the door test, it seems more than 2 stops.
3) Dennis, is the diffuser used the sole reason for the difference in light loss? Can you give an estimate on how many stops each of the diffuser options will lose?
Thanks
1) The M2 is vignetting in your tests...I'm guessing your point is to show the usable frame with each adapter? If so, that's quite a difference. Correct me if I'm wrong - using a 24mm lens on the M2 might offer the same fov as a 28mm on the Brevis, for eg?
2) The light loss between the adapters seems significant. How many stops would you say? Edit - based on the door test, it seems more than 2 stops.
3) Dennis, is the diffuser used the sole reason for the difference in light loss? Can you give an estimate on how many stops each of the diffuser options will lose?
Thanks
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Dennis Wood
DVXuser Sponsor
The standard on my test cam (soon to be the A1, so I'll update) is .5 stops lost using a 50mm f1.4 and the same distance/framing with and without the adapter.
Option 1 is about .3 to .5 more, and option 2 likely ~ .5 more again for a total of 1 to 1.3 total loss. The diffusion level of option 2 is however much higher, in the order of 2.5x for incredibly shallow DOF. It, however, will still need ND filters in bright conditions.
Option 1 is about .3 to .5 more, and option 2 likely ~ .5 more again for a total of 1 to 1.3 total loss. The diffusion level of option 2 is however much higher, in the order of 2.5x for incredibly shallow DOF. It, however, will still need ND filters in bright conditions.
rgdfilms
Wet poodle
Dennis, Is option #2 the one coming out in December? Right now, if someone were to order your adapter, they would get the standard diffuser, then they have the option of getting the Option 1 or Option 2 diffuser? I am guessing your diffusers climb in stages of deeper DOF/higher light loss?
Lenilenapi
Carbonite Member
Dennis, what do you mean by "The diffusion level of option 2 is however much higher"
I take the word diffusion to mean something akin to a promist filter that spreads highlights and/or softens the picture. You seem to mean this entirely differently.
Also I imagine I would want to at least start with a diffusion screen that gives me the closest thing to a clean pure sharp image, as a film image would be.
I don't at all understand how the diffusion screen could be affecting DOF unless it just making the entire epicture soft of overall., but that'snot the same as DOF.
Could you just explain what higher levels of diffusion do in your unit?
I take the word diffusion to mean something akin to a promist filter that spreads highlights and/or softens the picture. You seem to mean this entirely differently.
Also I imagine I would want to at least start with a diffusion screen that gives me the closest thing to a clean pure sharp image, as a film image would be.
I don't at all understand how the diffusion screen could be affecting DOF unless it just making the entire epicture soft of overall., but that'snot the same as DOF.
Could you just explain what higher levels of diffusion do in your unit?
Thank you Richard. It is a GREAT job.
I was thinking to buy Brevis before i saw the footages.
Although i like Brevis (because of it size) M2 footages is more DOF and more filmic than Brevis. They are not the same.M2 is clear winner in DOF and filmic look. Even i show the clip to my friend (who dont understand 35mm, dof etc. He said M2 is more and more film look and DOF)
But i do not want to bring a rod or tripod with my DVX100b so M2 is not a case for me.
Can anybody suggest me a 35mm adapter with the same size of Brevis and same dof or picture quality with M2? Or not invented yet????
Ergin
I was thinking to buy Brevis before i saw the footages.
Although i like Brevis (because of it size) M2 footages is more DOF and more filmic than Brevis. They are not the same.M2 is clear winner in DOF and filmic look. Even i show the clip to my friend (who dont understand 35mm, dof etc. He said M2 is more and more film look and DOF)
But i do not want to bring a rod or tripod with my DVX100b so M2 is not a case for me.
Can anybody suggest me a 35mm adapter with the same size of Brevis and same dof or picture quality with M2? Or not invented yet????
Ergin
rgdfilms
Wet poodle
Well Ergin, there was this LEGEND around here once called the G35, a.k.a. the Cinemek which probably had the best looking latitude and DOF from any adapter out there. www.cinemek.com - Nobody knows what happened to these guys. If they released their adapter sooner, they would have been the KINGS of the market... From what I remember they had a similar light weight design like the Brevis and I believe they used a type of wax formula for the ground glass - The cool thing about the Brevis is that they will be releasing alternative ground glass options in the near future. You will be able to install these alternative elements and get different looks and deeper DOF like what you're looking for. That should be pretty interesting to say the least.. I always though the MovieTube was pretty badass as well.. it better be for $13k +
Patryk_Rebisz
Veteran
Guys don't ***** about different DOF as much of the Brevis stuff is shot at f4 and M2 at f1.8 -- and yet M2 is still darker... The loss of light with M2 is really significant from my experience. ANyone in NYC area who has Brevis adapter and want to test the stuff with me?
Dennis Wood
DVXuser Sponsor
Len, diffusion level and DOF are closely linked, as is light loss. So when I say that option 2 is 2.5x more diffuse, it means that the DOF is much, much shallower using it. You will not see a difference in sharpness so much as an increase in light loss. Option 2 is the closest to film I've ever seen with this adapter. You can use the term diffuser or GG to describe the same part...but the Brevis diffusers are so removed at this point from ground glass, it seems misleading to call them that.
I'll be posting up some A1 footage (should be here today) that will illustrate the differences. The whole idea is to allow shooters to pick the level of diffusion because to many, low light loss and sharpness is the number one criteria. Others worry less on light but want the shallowest DOF and film emulation possible. We have a diffuser option at this point for everyone. We wanted to start with light loss as the number one criteria, and then add options from there. As time goes by, and testing is done, we've started to merge several technologies now in the diffusers.
The options swap in and require 5 minutes or so once you've done it a few times.
I'll be posting up some A1 footage (should be here today) that will illustrate the differences. The whole idea is to allow shooters to pick the level of diffusion because to many, low light loss and sharpness is the number one criteria. Others worry less on light but want the shallowest DOF and film emulation possible. We have a diffuser option at this point for everyone. We wanted to start with light loss as the number one criteria, and then add options from there. As time goes by, and testing is done, we've started to merge several technologies now in the diffusers.
The options swap in and require 5 minutes or so once you've done it a few times.
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Lenilenapi
Carbonite Member
Dennis, as you know I have a Brevis on order and love the idea of multiple choice diffusers, so I'm certainly not taking a critical point of view here.
However I am still totally confused by the use of the term DOF on these pages.
As I understand it, Depth of Field is an objective, measurable optical phenomena that is dependant only on lens, f-stop and the size of the target image area. The only possible variable is what circle of confusion is accepted as "out of focus" for the medium ( I think 16 & 35 might be diffferent) but I'm not sure even that is ever considered a variable.
It seems to me when you say diffusers change the DOF, you must be describing some optical phenomena that appoximates DOF, maybe its a "perceived DOF" based on the way light scatters in the diffuser, but I would like to see it separated from the optical term DOF.
This stuff is bending my brain a little. Enlighten me if I am missing something.
How does a diffuser change the optical DOF?
I look forward to seeing the image comparisons - even more to receiving my Brevis.
- Lenny Levy
However I am still totally confused by the use of the term DOF on these pages.
As I understand it, Depth of Field is an objective, measurable optical phenomena that is dependant only on lens, f-stop and the size of the target image area. The only possible variable is what circle of confusion is accepted as "out of focus" for the medium ( I think 16 & 35 might be diffferent) but I'm not sure even that is ever considered a variable.
It seems to me when you say diffusers change the DOF, you must be describing some optical phenomena that appoximates DOF, maybe its a "perceived DOF" based on the way light scatters in the diffuser, but I would like to see it separated from the optical term DOF.
This stuff is bending my brain a little. Enlighten me if I am missing something.
How does a diffuser change the optical DOF?
I look forward to seeing the image comparisons - even more to receiving my Brevis.
- Lenny Levy
Lenilenapi
Carbonite Member
RGD,
You've mentioned that on the Brevis you were shooting at Z75 F10.
What were you using for the Redrock?
Also did you consider trying to switch achromats or is the Brevis achromat built into the system?
Lenny Levy
You've mentioned that on the Brevis you were shooting at Z75 F10.
What were you using for the Redrock?
Also did you consider trying to switch achromats or is the Brevis achromat built into the system?
Lenny Levy
Please see the attached stills taken from the Richard's footage.
I still do not understand why there is such a difference in DOF.
Patryk; both stills have the same f-stop. So we should consider them equal.
It seems there are quite light loss in M2. I agree..
Dennis explain the difference?:huh: Is the a reason what we miss?? (By the way i am a fan of Brevis!)
Ergin
</IMG>
I still do not understand why there is such a difference in DOF.
Patryk; both stills have the same f-stop. So we should consider them equal.
It seems there are quite light loss in M2. I agree..
Dennis explain the difference?:huh: Is the a reason what we miss?? (By the way i am a fan of Brevis!)
Ergin
</IMG>
Attachments
Lenilenapi
Carbonite Member
Interesting comparisons.
It seems like there is an overall softness in the M2 footage but its hard to see how that would explain all the apparent DOF difference. It might.
Also I notice that the treatment of highlights is different. The M2 seemes a bit more like a Low con effect where the highlights are being diffused into the image a bit more and never get quite as hot as they do in the Brevis. This fits in with Dennis's description of how different diffusers work.
But maybe the window light (if it was a window) changed in between shots.
It seems like there is an overall softness in the M2 footage but its hard to see how that would explain all the apparent DOF difference. It might.
Also I notice that the treatment of highlights is different. The M2 seemes a bit more like a Low con effect where the highlights are being diffused into the image a bit more and never get quite as hot as they do in the Brevis. This fits in with Dennis's description of how different diffusers work.
But maybe the window light (if it was a window) changed in between shots.
Justyn
Veteran
I'd say the same thing. The Rerock has a narrower DOF atleast with Richards Set-up now... but man it's a much softer image.. and that light loss is WAY signifigant. The Brevis looks sweet, especially with that rod support and the new options... but the noise would really end up killing my audio guy... and I'd be wrapped in sound blankets...
The edge sotness of the M2 had always looked a bit odd... doesn't seem to have that with the Brevis.... The only other thing is that if we were saying this to people I think they'd confuse it and think I was talking about Bevis and Butthead. How did you come up with this name?
Good review Richard... I would also like to see that SGpro included.. Some sweet looking stuff with that one.
The edge sotness of the M2 had always looked a bit odd... doesn't seem to have that with the Brevis.... The only other thing is that if we were saying this to people I think they'd confuse it and think I was talking about Bevis and Butthead. How did you come up with this name?
Good review Richard... I would also like to see that SGpro included.. Some sweet looking stuff with that one.
Dennis Wood
DVXuser Sponsor
The DOF of field calc does not mathematically change, but it sure looks different as diffusion level changes. Out of focus areas become much more blended, basically hiding more detail (in out of focus areas) as diffusion level goes up. This extreme diffuse look is described by some as "cinematic" mostly I think as it comes very close to the look of film on a wide open lens. I wasn't going to do this, but here's a grab from the old GS400 and the latest diffuser. Although shot a bit hot, you can still see how the extra diffusion affects the out of focus regions.
The A1 did come in today but there was little time to play. Other than making sure the cam worked, and framing up the GG, I only shot a few minutes in the shop. Btw, this unit is being tested with the new drive system and is virtually silent. It will work in any of the current adapters, but I won't release it until more confidence testing is done. I'll post up some footy from the prototype option 2 diffuser in a day or two once I figure the A1 out a bit better Until then, a teaser.
The A1 did come in today but there was little time to play. Other than making sure the cam worked, and framing up the GG, I only shot a few minutes in the shop. Btw, this unit is being tested with the new drive system and is virtually silent. It will work in any of the current adapters, but I won't release it until more confidence testing is done. I'll post up some footy from the prototype option 2 diffuser in a day or two once I figure the A1 out a bit better
Until then, a teaser.
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