So it is the light transmission of the GG that plays this "trick"... but I still don't understand how it would shave off different percentages of the total light on different total amounts of light?
Anyone know where there is some flipped HD?
Does Letus Extreme lose more light than Brevis
- Thread starter Cinemano
- Start date
So it is the light transmission of the GG that plays this "trick"... but I still don't understand how it would shave off different percentages of the total light on different total amounts of light?
Anyone know where there is some flipped HD?
Lenilenapi
Carbonite Member
It is reacting to the size of the iris and the angle at which the light from that iris hits the GG. Its not that hard to visualize how this could happen.
A denser screen scatters light in more directions is my guess, and so it would also scatter light from the more radical directions more to the center as well.
A denser screen scatters light in more directions is my guess, and so it would also scatter light from the more radical directions more to the center as well.
Dennis Wood
DVXuser Sponsor
Leni, did you try VLC (videolan.org) ? I can re-encode to wmv for you if that works better...
US, the flip modules started shipping in volume a few days ago, so for now, this will have to do: http://www.cinevate.com/phpBB2/viewtopic.php?t=1496 It was shot using a preliminarly setup, so expect even better performance from the currently shipping unit.
US, the flip modules started shipping in volume a few days ago, so for now, this will have to do: http://www.cinevate.com/phpBB2/viewtopic.php?t=1496 It was shot using a preliminarly setup, so expect even better performance from the currently shipping unit.
Barry_Green
Moderator
Well, if that's the answer, that's a great-big "duh" moment and a slap-my-forehead, why-didn't-I-think-of-that issue. If the iris is actually physically bigger than the screen and thus affording no occlusion, such that the adapter can "see" straight through... interesting. This would make no sense in the case of a solid surface (such as front projection) but if it's a transparent/translucent element...
But, wouldn't that run counter to the assertion that the Brevis is the one that's most immune to light changes at the largest apertures? As I understand your suggestion, wouldn't a smaller imaging screen be "fully bright" at deeper f-stops (since the camera is still looking "straight through"? Yet the Brevis has one of the largest imaging screens.
Barry_Green
Moderator
Oh, and thanks to the incredibly responsive members of the DVXUser community, it looks like I'll be able to test a Brevis in Feb. after I get back from this Wounded Warriors school stint.
Michael Friedman
Active member
Yeah, it sort of just dawned on me today. I think it must explain a great deal of it.
As for why it is more apparent in the Brevis, I don't know. Perhaps it is the most translucent? I don't own one, I don't know. Maybe it has just not been tested as definitively on other adapters.
Not at all, it's better for the community when you do. But you were being more direct than that and leaving less room.
I did my own test with my Brevis and SGpro with 50mm 1.8 Nikon, recording my HVX's lcd (with zebra) with my HV20. Not a patch on Dennis' test
, but it showed similar results - there was no discernable light loss from f1.8 to f4 (almost certainly less than half a stop). f4 to f5.6 appeared to lose 1 stop. The SGpro's light loss was linear (1 stop seemed to = 1stop).Exposure changes (or lack of change) seemed to be consistent across the entire frame - but this is the most speculative of my findings.
I can post a quicktime but I'm guessing there's not much need after Dennis' effort.
Dennis Wood
DVXuser Sponsor
Barry, Lenny is on the right track. There are a few concepts at play with our imaging elements that are not part of conventional optics thinking when it comes to f stops and the like. It is fascinating (regardless of one's prowess in physics) to quantify the interplay I should have posted a test like this a year ago, but I assumed the light efficiency topic (gain, loss yada yada) had been resolved long ago with the Brevis.
I should have posted a test like this a year ago, but I assumed the light efficiency topic (gain, loss yada yada) had been resolved long ago with the Brevis.
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I would LOVE to see a Quicktime of the effect in real time. The Waveform explanation was a great one, glad the effort was made. I'm gonna strap the HVX and Letus up to On Location not to test the linearity of light loss, but the uniformity.
Does the Hot Spot theory make more sense with Michael's theory? If in fact the ground glass was just that thin and the Brevis screen is that much larger than the rest, that could contribute to the phenomena.
What really amazes me, still, is that Phillip Bloom was stopped down to F8 in that light and things were still too bright for comfort. Camera and Lens at F8? Wouldn't that make the image extremely hard to control in that case?
Edit: QUESTION FOR DENNIS WOOD--
How far is the ground glass from the actual lens of the HVX? Is it closer to the end of the unit or to the camera side? And, how close is the achromat to the actual camera Lens?
Someone in LA wanna let me play with their Brevis?
Does the Hot Spot theory make more sense with Michael's theory? If in fact the ground glass was just that thin and the Brevis screen is that much larger than the rest, that could contribute to the phenomena.
What really amazes me, still, is that Phillip Bloom was stopped down to F8 in that light and things were still too bright for comfort. Camera and Lens at F8? Wouldn't that make the image extremely hard to control in that case?
Edit: QUESTION FOR DENNIS WOOD--
How far is the ground glass from the actual lens of the HVX? Is it closer to the end of the unit or to the camera side? And, how close is the achromat to the actual camera Lens?
Someone in LA wanna let me play with their Brevis?
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Dennis Wood
DVXuser Sponsor
That's why I've also been guilty of the broken record effect regarding using external NDs with the Brevis. If you want more light control, we've got CFLe and CF3Le to do just that. Their response curves are different, and the swap only takes a few minutes. We learned early on that every shooter has a different idea of what the perfect adapter is. We're not there yet, but no one would accuse us of not pushing forward constantly to that end. Even in blinding sun on new snow, I've found a .9ND and polarizer adequate when used with the taking lens at f5.6 or so, camera at f8. This was shot using those settings: http://cinevate.com/phpBB2/viewtopic.php?t=559 in the brightest setting I believe anyone would encounter.
Kholi, remember that you must baseline your taking lens and camera before you test the adapter...and you must baseline in the 50 IRE area. Your camera's gamma tweaks for knee and stretch will mess with your results otherwise. (check this: http://www.24pdigitalcinema.com/cinegamma.pdf) The curve (referring to waveform monitor rendering of an evenly lit white surface) of an HV20 for example at full zoom is nearly a perfect arc...and this is 100% due to the camera's lens. The XH-A1 however, happens to have a very flat response throughout the zoom range and is so a good condidate for this type of testing.
Kholi, remember that you must baseline your taking lens and camera before you test the adapter...and you must baseline in the 50 IRE area. Your camera's gamma tweaks for knee and stretch will mess with your results otherwise. (check this: http://www.24pdigitalcinema.com/cinegamma.pdf) The curve (referring to waveform monitor rendering of an evenly lit white surface) of an HV20 for example at full zoom is nearly a perfect arc...and this is 100% due to the camera's lens. The XH-A1 however, happens to have a very flat response throughout the zoom range and is so a good condidate for this type of testing.
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Jason Ramsey
Admin
Ok. I attempted my own series of tests similar to what I watched Dennis do in that video. I did a crude version of this last night. Tonight I did a little less crude version, but still pretty crude nonetheless.
First a couple of disclaimers:
I have no real preference of one adapter over the other. I've only ever shot with the Brevis. When I started looking for an adapter on the cheap some months ago to start learning I came across a Brevis on the cheap. I think it started it's days as a beta unit and has been upgraded a couple of times since then. It's a Rev2 now. Doesn't have the latest "MC" (micro collimation) upgrade to it. Anyhow, I found a good deal on an adapter and I bit. It uses CF1L as it's diffuser. This is without the flip module. Beyond that... if I had the money, there's a few adapters out there I would like to buy, each for their own unique traits. So, I happen to own a Brevis, and one single lens... It's NOT a matter of preference of this adapter over that adapter or whatever. Having never had extensive experience with any adapter let alone my limited experience with this one, it would be quite ignorant of me to prefer one over the other... at least in terms of picture quality. Feature set, well that's another matter.
This is not scientific by any means, but I will try to document what I did on my own as much as possible. There will be details I'll leave out for time and boredom's sake, but on request, I may be able to provide some of them.
I've never done this sort of shooting tests and things. I just shoot footage and look at the picture. I don't get all scientific, so this is a first, and I am by no means an experienced "tester" of this sort.
Anyways, I just wanted to try to do something similar to what Dennis did and document my results.
First, I stopped the HVX lens from f4 to f5.6 to f8 to f11. One stop of light, right? I did this with the bare HVX... The only reason I started at f4 was because that was the most open I could be before overexposing the frame with the light I had set up.
As those of you who have read Barry's book or operate with the HVX know, getting exactly 1 stop increments is a bit hard just going off of the lcd readout b/c the HVX actually has 3 ticks of exposure change for every fstop number readout... Meaning in the f5.6 range, there is actually three subtle exposure changes before it will change to the next fstop range on the HVX.
Anyways, so one stop is not exact, and I allow for a margin for error for that. It was just to get an idea (using the marker function on the HVX) of the IRE change with one stop change in iris. Due to what was stated above, it varied a bit from number to number but a good average IRE change for one stop seemed to be around 20 IRE. That's what Dennis quotes, so that's what I figured as "close enough".
I also panned across the page and noted the IRE change in the LCD readout of the HVX from center of paper (I was filming a white piece of paper) to the edges of the paper. My reasoning behind this was just to get an idea of how uneven the lighting on the page may have been so I could take that into account when looking at the waveform in EDIUS later. The difference was that the center of the page was about 2-3 IRE brighter than one edge, and maybe 3-4 IRE on the other edge... More on this later....
But, that's basically my starting point. Approximately 20 IRE seemed to be about the equivalent of 1 stop of light, and a variance of 2-4 IRE across the page in light as I panned across the page checking for changes in IRE.
So....
HVX @ f5.6 gives me a reading of around 74 IRE at center of page. (Note: I took exact X,Y coordinates and noted the IRE for the center of page and corners of the page in EDIUS' waveform. I did this both with the bare lens and the adapter on. Can post those numbers later if requested).
Anywho... Bare HVX @5.6 gives about a 74 IRE at center of page...
Attach the Brevis and a 50mm f1.4 @ f1.4 and I get about 57-58 IRE at the exact same coordinates.
(it should be noted that there is a margin for error of about + or - 1.5 IRE when footage is being played back. One would assume, grain pattern or whatever. This is evident in both the bare lens and the brevis attached numbers. So keep that in mind).
Anyways... f 1.4 is one stop of light, is that right?
I am showing approximately one stop of light loss from bare HVX @ 5.6 vs HVX @5.6 with Brevis attached and 50mm lens at 1.4.
Kinda peculiar to me. Should be a bit more. I would think. One thing I would like to make note of here though, is: Apparently changing your focus will effect the IRE readout. I was at about MF09 with the Brevis attached. Without it I went to something around MF26... don't really remember. But, I did notice that as I changed to focus of the HVX lens after taking the Brevis off, the IRE readout on the LCD of my HVX began to change as well... I don't know remember which way it went, b/c I didn't think much of it at the time. But, it is worth noting that it did change, and that could account for some discrepency... I mean, if it became 10 IRE darker as I changed focus, then that could amount for the missing .5 stops that should be showing from the Brevis' light loss... I don't remember how much or which way the IRE went, but it changed when I changed focus on the HVX lens. Worth noting.
The Brevis with no lens shows about a 10 IRE difference from the bare HVX, so one would think that a lens losing a stop of light, an adapter losing a half a stop would amount to 1.5 stops. I never gave this much thought until when I just looked at it on the waveform (again, I'm inexperienced at this kind of thing). But, I'm showing about a 20 IRE difference taking into account margin for error, etc. with the brevis and lens attached from the bare HVX.
Ok...
So, as I stop through the fstop increments (correct me if I am wrong but these are all one stop of light increments, same as what I did with the bare HVX) on the 50mm lens here's what I see in IRE change...
From F1.4 to F2.0 = Zero change.
From F2.0 to F2.8 = Approximately 1 IRE change
From F2.8 to F4.0 = About 4 IRE change.
If I have a clue what I'm talking about, F1.4 to F4.0 would be 3 stops of light, correct? I'm showing only about 7 IRE at this point... taking into account margin for error, etc... maybe half a stop or so. Continuing on...
From F4.0 to F5.6 = about 7 IRE change. So, this would be about the same IRE change going from 4.0 to 5.6 as going from 1.4 to 4.0 was.
From F5.6 to F8.0 About 21 IRE (approximately 1 stop... now it's more in line with 1 stop change in iris = one stop of light lost, as it was with the bare HVX)
From F8.0 to F11 = About 20 IRE
From F11 to F16 = About 19 IRE
Ok, so this is just what I saw, nothing more, nothing less, and by no means scientific.
Next thing is light falloff of the bare HVX vs. the Brevis w/ 50mm lens attached.
First remember what I stated above about there being a 2-4 IRE variance from center of page to edges of page.
The bare HVX shows pretty much an IRE in line with that. It's pretty flat.
The HVX w/ Brevis and lens attached shows a slight curve in addition to the variance. Maybe an addition 3 IRE, maybe 4... it's hard to tell.
I'm pretty much looking at a 2-3 IRE variance from center to one edge with the bare HVX, and about 5 IRE from center to the same edge at the same coordinance with the Brevis and lens attached.
This could be b/c of the diffuser in the brevis, or my lens, or a combination of both, but there is a slight variance that I can't see with my naked eye, but can see on the waveform.
Anyways, I think that pretty much covers it, I guess.
I find this an interesting discussion, and a confusing one, so I thought I might make better sense of it if I tried it myself... I actually learned a bit about how light loss is supposed to function by observing the HVX lens, which only made me confused as to why the same wasn't true when stopping down the 35mm lens... at least until I hit f8 or so, then things matched up what the HVX does.
Anywho... that's what I saw. Take it for a grain of salt, of course.
Now, I seem to remember Lenny stating that the Letus Extreme had a similar effect as what is being talked about here in relation to the Brevis, although not as pronounced... But, the light loss on the Extreme (particularly in the more wide open apertures) was not stop for stop with the Extreme either... IIRC.
later,
Jason
First a couple of disclaimers:
I have no real preference of one adapter over the other. I've only ever shot with the Brevis. When I started looking for an adapter on the cheap some months ago to start learning I came across a Brevis on the cheap. I think it started it's days as a beta unit and has been upgraded a couple of times since then. It's a Rev2 now. Doesn't have the latest "MC" (micro collimation) upgrade to it. Anyhow, I found a good deal on an adapter and I bit. It uses CF1L as it's diffuser. This is without the flip module. Beyond that... if I had the money, there's a few adapters out there I would like to buy, each for their own unique traits. So, I happen to own a Brevis, and one single lens... It's NOT a matter of preference of this adapter over that adapter or whatever. Having never had extensive experience with any adapter let alone my limited experience with this one, it would be quite ignorant of me to prefer one over the other... at least in terms of picture quality. Feature set, well that's another matter.
This is not scientific by any means, but I will try to document what I did on my own as much as possible. There will be details I'll leave out for time and boredom's sake, but on request, I may be able to provide some of them.
I've never done this sort of shooting tests and things. I just shoot footage and look at the picture. I don't get all scientific, so this is a first, and I am by no means an experienced "tester" of this sort.
Anyways, I just wanted to try to do something similar to what Dennis did and document my results.
First, I stopped the HVX lens from f4 to f5.6 to f8 to f11. One stop of light, right? I did this with the bare HVX... The only reason I started at f4 was because that was the most open I could be before overexposing the frame with the light I had set up.
As those of you who have read Barry's book or operate with the HVX know, getting exactly 1 stop increments is a bit hard just going off of the lcd readout b/c the HVX actually has 3 ticks of exposure change for every fstop number readout... Meaning in the f5.6 range, there is actually three subtle exposure changes before it will change to the next fstop range on the HVX.
Anyways, so one stop is not exact, and I allow for a margin for error for that. It was just to get an idea (using the marker function on the HVX) of the IRE change with one stop change in iris. Due to what was stated above, it varied a bit from number to number but a good average IRE change for one stop seemed to be around 20 IRE. That's what Dennis quotes, so that's what I figured as "close enough".
I also panned across the page and noted the IRE change in the LCD readout of the HVX from center of paper (I was filming a white piece of paper) to the edges of the paper. My reasoning behind this was just to get an idea of how uneven the lighting on the page may have been so I could take that into account when looking at the waveform in EDIUS later. The difference was that the center of the page was about 2-3 IRE brighter than one edge, and maybe 3-4 IRE on the other edge... More on this later....
But, that's basically my starting point. Approximately 20 IRE seemed to be about the equivalent of 1 stop of light, and a variance of 2-4 IRE across the page in light as I panned across the page checking for changes in IRE.
So....
HVX @ f5.6 gives me a reading of around 74 IRE at center of page. (Note: I took exact X,Y coordinates and noted the IRE for the center of page and corners of the page in EDIUS' waveform. I did this both with the bare lens and the adapter on. Can post those numbers later if requested).
Anywho... Bare HVX @5.6 gives about a 74 IRE at center of page...
Attach the Brevis and a 50mm f1.4 @ f1.4 and I get about 57-58 IRE at the exact same coordinates.
(it should be noted that there is a margin for error of about + or - 1.5 IRE when footage is being played back. One would assume, grain pattern or whatever. This is evident in both the bare lens and the brevis attached numbers. So keep that in mind).
Anyways... f 1.4 is one stop of light, is that right?
I am showing approximately one stop of light loss from bare HVX @ 5.6 vs HVX @5.6 with Brevis attached and 50mm lens at 1.4.
Kinda peculiar to me. Should be a bit more. I would think. One thing I would like to make note of here though, is: Apparently changing your focus will effect the IRE readout. I was at about MF09 with the Brevis attached. Without it I went to something around MF26... don't really remember. But, I did notice that as I changed to focus of the HVX lens after taking the Brevis off, the IRE readout on the LCD of my HVX began to change as well... I don't know remember which way it went, b/c I didn't think much of it at the time. But, it is worth noting that it did change, and that could account for some discrepency... I mean, if it became 10 IRE darker as I changed focus, then that could amount for the missing .5 stops that should be showing from the Brevis' light loss... I don't remember how much or which way the IRE went, but it changed when I changed focus on the HVX lens. Worth noting.
The Brevis with no lens shows about a 10 IRE difference from the bare HVX, so one would think that a lens losing a stop of light, an adapter losing a half a stop would amount to 1.5 stops. I never gave this much thought until when I just looked at it on the waveform (again, I'm inexperienced at this kind of thing). But, I'm showing about a 20 IRE difference taking into account margin for error, etc. with the brevis and lens attached from the bare HVX.
Ok...
So, as I stop through the fstop increments (correct me if I am wrong but these are all one stop of light increments, same as what I did with the bare HVX) on the 50mm lens here's what I see in IRE change...
From F1.4 to F2.0 = Zero change.
From F2.0 to F2.8 = Approximately 1 IRE change
From F2.8 to F4.0 = About 4 IRE change.
If I have a clue what I'm talking about, F1.4 to F4.0 would be 3 stops of light, correct? I'm showing only about 7 IRE at this point... taking into account margin for error, etc... maybe half a stop or so. Continuing on...
From F4.0 to F5.6 = about 7 IRE change. So, this would be about the same IRE change going from 4.0 to 5.6 as going from 1.4 to 4.0 was.
From F5.6 to F8.0 About 21 IRE (approximately 1 stop... now it's more in line with 1 stop change in iris = one stop of light lost, as it was with the bare HVX)
From F8.0 to F11 = About 20 IRE
From F11 to F16 = About 19 IRE
Ok, so this is just what I saw, nothing more, nothing less, and by no means scientific.
Next thing is light falloff of the bare HVX vs. the Brevis w/ 50mm lens attached.
First remember what I stated above about there being a 2-4 IRE variance from center of page to edges of page.
The bare HVX shows pretty much an IRE in line with that. It's pretty flat.
The HVX w/ Brevis and lens attached shows a slight curve in addition to the variance. Maybe an addition 3 IRE, maybe 4... it's hard to tell.
I'm pretty much looking at a 2-3 IRE variance from center to one edge with the bare HVX, and about 5 IRE from center to the same edge at the same coordinance with the Brevis and lens attached.
This could be b/c of the diffuser in the brevis, or my lens, or a combination of both, but there is a slight variance that I can't see with my naked eye, but can see on the waveform.
Anyways, I think that pretty much covers it, I guess.
I find this an interesting discussion, and a confusing one, so I thought I might make better sense of it if I tried it myself... I actually learned a bit about how light loss is supposed to function by observing the HVX lens, which only made me confused as to why the same wasn't true when stopping down the 35mm lens... at least until I hit f8 or so, then things matched up what the HVX does.
Anywho... that's what I saw. Take it for a grain of salt, of course.
Now, I seem to remember Lenny stating that the Letus Extreme had a similar effect as what is being talked about here in relation to the Brevis, although not as pronounced... But, the light loss on the Extreme (particularly in the more wide open apertures) was not stop for stop with the Extreme either... IIRC.
later,
Jason
Barry_Green
Moderator
... most fascinating...
I cannot wait to get a firsthand look at this. There has to be some explanation.
The assertion is that you can stop down a lens from f/1.4 to f/5.6 (being that you're transmitting 1/16th as much light) and yet the net effect is to cut the amount of actual light transmission only in half. Surely you can see how that sounds like snake oil, right? Yet the Cinevate movie and Jason are reporting comparable results, without excessive hot-spotting.
Most bizarre. It defies all logic. Well, it can't defy *all* logic, there's just logic applying that we don't have yet... bizarre...
I cannot wait to get a firsthand look at this. There has to be some explanation.
The assertion is that you can stop down a lens from f/1.4 to f/5.6 (being that you're transmitting 1/16th as much light) and yet the net effect is to cut the amount of actual light transmission only in half. Surely you can see how that sounds like snake oil, right? Yet the Cinevate movie and Jason are reporting comparable results, without excessive hot-spotting.
Most bizarre. It defies all logic. Well, it can't defy *all* logic, there's just logic applying that we don't have yet... bizarre...
pureHVX
Member
Wow, this thread is moving fast. I want to chime in as that owner of both a flipped Brevis and a Canon K-35 zoom, yes you can use them together. In fact (as was described) I could as well with three spacer tubes attached to the non-flipped Brevis, but personally didn't care for the resulting length.
And yes, the combination of the new achromat lens and the longer path resulting from the flip vastly improves upon the non-flipped results. In fact, I can now zoom all the way in on the HVX200 using the flip module. Such a vast improvement is noticeable immediately.
I rented the flip out for Paul Nordin's shoot with cinema primes and the comment from both DPs working it was that it was much better than a non-flipped, and now truly comparable to the P+S Technik in quality of image. Having shot plenty with both, this claim doesn't come lightly.
If Paul doesn't post some of the footage from that shoot soon, I'll have some from a shoot I'm doing Sunday.
Jason
And yes, the combination of the new achromat lens and the longer path resulting from the flip vastly improves upon the non-flipped results. In fact, I can now zoom all the way in on the HVX200 using the flip module. Such a vast improvement is noticeable immediately.
I rented the flip out for Paul Nordin's shoot with cinema primes and the comment from both DPs working it was that it was much better than a non-flipped, and now truly comparable to the P+S Technik in quality of image. Having shot plenty with both, this claim doesn't come lightly.
If Paul doesn't post some of the footage from that shoot soon, I'll have some from a shoot I'm doing Sunday.
Jason
not having read anything past this that I quote:
I am not getting this still... the general angle of the incoming light is perpendicular to the GG, so do you mean the angle at which the light leaves the GG towards the flip and later the camera? But why is it that there is a sudden drop when the size of the image on the GG is constant? I thought there might be a sudden drop in the amount of light captured by the first element but if the projection on the GG remains of equal size at all times then that doesn't make sense...
What angle is it you are talking about?
Dennis Wood
DVXuser Sponsor
Jason, those numbers are pretty consistent with our findings. In the test we did today, the Brevis with CF1Le and the 50mm lens at f1.4 lost about half the amount of light that we observed while stopping the bare camera down from f2.8 to f4.0 (1 stop). So the entire system loss was just over half a stop.
What you are illustrating though is that quoting light loss without attaching a lens doesn't really tell a potential customer what to expect. Intuitively, affixing a 50mm f1.4 should result in 1 stop of light loss to the system..and it does not. It shows about half of what's expected, and then completely misbehaves by showing 1 stop loss to the camera, as five stops are dialed in on the 50mm! CF1Le was engineered, by the way, specifically to flatten out that curve you were seeing...so my tests will look flatter than yours with CF1L installed. Again, CF2Le and CF3Le do not behave quite this way, and the light loss curve is different. I could have bought a few nice cars with the R&D dollars invested into these little elements
Jason (pureHVX), thanks for piping in here. You're one of the first shooters to have used the flip in the field, and we're hoping the rest of our customers are as happy with the system.
What you are illustrating though is that quoting light loss without attaching a lens doesn't really tell a potential customer what to expect. Intuitively, affixing a 50mm f1.4 should result in 1 stop of light loss to the system..and it does not. It shows about half of what's expected, and then completely misbehaves by showing 1 stop loss to the camera, as five stops are dialed in on the 50mm! CF1Le was engineered, by the way, specifically to flatten out that curve you were seeing...so my tests will look flatter than yours with CF1L installed. Again, CF2Le and CF3Le do not behave quite this way, and the light loss curve is different. I could have bought a few nice cars with the R&D dollars invested into these little elements
Jason (pureHVX), thanks for piping in here. You're one of the first shooters to have used the flip in the field, and we're hoping the rest of our customers are as happy with the system.
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Jason Ramsey
Admin
All I know is now that I actually have a bit of an understanding about how things "should" behave in regards to light loss after doing that test, I'm more confused than ever :beer:
It doesn't make sense... so someone needs to find whatever the logical explanation to it is.
Later,
Jason
It doesn't make sense... so someone needs to find whatever the logical explanation to it is.
Later,
Jason
Kholi, quicktime, for sure. Quick and dirty...
http://www.conceptsmith.com.au/brevis.mov
I love the SGpro's bokeh, and I love the idea that the Brevis is more sensitive with 35mm lens (my 50mm anyway) at f4 than the SG with lens wide open. I'm keeping both, but man this is an expensive game.
http://www.conceptsmith.com.au/brevis.mov
I love the SGpro's bokeh, and I love the idea that the Brevis is more sensitive with 35mm lens (my 50mm anyway) at f4 than the SG with lens wide open. I'm keeping both, but man this is an expensive game.
Dennis... Barry... Tim Michael Jason... crap! all of you guys that know WAY more than me 'bout cameras... the list is just too dang big
Guys... IF, and that's unfortunately a bigger if than I'd like... but IF I can get the Nikon 28-70 and 80-200 2.8's... should I? Cause if 2.8 is the same as 1.4 well then HECK, the zooms are said to be sharper than Nikon primes!
I just looked at the 720 from the flipped Brevis, and besides some minor but present hot-spotting I was quite pleased... I would like to see a bit more definition from time to time but it is most definitely a nice image... and I was already I was planning on getting the RedRock mattebox with a (half a built in) ND and a polarizer... but would that be enough to control the light? on a frozen snowed-over lake?!? not kiddin' about that, I mean it about the white lake... (Dennis I was SO happy to see your lake footage!)
Also, did you guys just say you could zoom? if so how much cause that would multiply your focal lenghts when using a set of primes.
Guys... IF, and that's unfortunately a bigger if than I'd like... but IF I can get the Nikon 28-70 and 80-200 2.8's... should I? Cause if 2.8 is the same as 1.4 well then HECK, the zooms are said to be sharper than Nikon primes!
I just looked at the 720 from the flipped Brevis, and besides some minor but present hot-spotting I was quite pleased... I would like to see a bit more definition from time to time but it is most definitely a nice image... and I was already I was planning on getting the RedRock mattebox with a (half a built in) ND and a polarizer... but would that be enough to control the light? on a frozen snowed-over lake?!? not kiddin' about that, I mean it about the white lake... (Dennis I was SO happy to see your lake footage!)
Also, did you guys just say you could zoom? if so how much cause that would multiply your focal lenghts when using a set of primes.
Dennis Wood
DVXuser Sponsor
Not to worry on the bokeh issue Steve...stay tuned on that one. Us, we deliberately test with cheap ugly zooms (you can get them used for next to nothing)...and they work extremely well. I've got a 28-200mm Canon f3.5 that is very usable, at all points in it's focal range. In fact, I ended using it at 28mm for the falls shots in our flipped footage example. Ben Winter shot this very amusing short .... with one f3.5 35-105 zoom lens.
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