Evangelos Achillopoulos

In my tests, in an ISO res chart I can?t see the resolution drop that you guys are claiming. I am comparing digiprimes with ultraprimes and DoF adapters, there is only a glare effect in the highlights which resembles the promist look. In MTF I can see the drop of contrast but the resolution is there. Probably your experience is limited to Pro35 which can?t allow experiment with different ground glass. The new ground glass solution in which am reaching, it hasn?t any of the above problems except of light loss. Which again it?s limited and can be accepted since cameras like RED are in the 250 ASA range and the HPX3000 and Varicam are in the 800ASA range?

Michael First the HDX900 is certainly NOT a Varicam they may have similar sensors but the similarity ends with a difference in latitude of 2,5 stops? The use of fast digiprimes to achieve filmic look with 2/3 cameras has past away from my mind the moment that I tried in my Varicam F a DoF adapter that I made. After six months of R&D we build a lens relay for 2/3 and Brevis35 the results are below The adaptor on a Varicam and a F900R the lenght of the system is similar to a Cinestyle zoom so no problem with ergonomics. All that with a cost of no more than 5000$... We are now developing a new ground glass for Brevis35 with no diffuse effect, no vingeting in very close aparture, no vigneting in wide angle lenses, no loss of contrast and resolution. The only trade off will be loss of sensitivity of 1 ¼ of stop. I have select Brevis35 as a host system for my development because is the only adapter, that I can change the ground glass in five minutes... Mike and Lindsay, there no way to get that kind of image with HDX900 regardless of Pro35 due to latitude inferiority against the Filmrec mode of Varicam and with HPX3000 that has the Filmrec mode of Varicam, you really need the DoF adapter to reach that result. Varicam, HPX3000 and F900R have an image invert function that allows using these adaptors without a prism to invert the image like Pro35. That gives a sharper image because of less glass in the image path. The HDX900 does not have the image invert function.

I can dare to suggest www.imatest.com . You can download the trial version and use the step chart function, export .Tiff 16bit and import it to step chart analyzer, select the area of the steps in the image, don?t forget to select 0,15D step or TS28D Danes Picta chart on the dialog, and let everything else to auto. The best range is on High quality and mid high or 0,1 f-stop noise level or 0,25 f-stop noise level. It?s a nice tool can be helpful, for reference I have put on my thread a set of popular cameras stills with the exact same chart. Have fun.

Where can I find more info about that ?difference? that 2/3 prism lens has? How much different they are or what is the result in use of flat photo lenses in prism based cameras? Do they introduce aberrations and what kind?

Joofa thanks for your kind words, but I thing there is no point to reverse engineer RED original curves since am interested on how I can use the RED RAW converting to something useful to our post production and DI process. If you want to do that your welcome from me to use the .R3D file in order to make that research? Any one with some results from the charts??

For same weird reason the FTP does not allow .R3D files to be downloaded? So I add in the filename at the end a .zip extension? After you have downloaded the file remove the extra extension .zip from the filename. The new link is A001_C004_080314_001.R3D.zip Sorry for the inconvenience.

For many of you, am the guy that is chasing Jim and Graeme about RED latitude… It’s not exactly that, instead, am an engineer that has above all, the axiom to be objective. So in order to do my job as a DIT/DI supervisor/Production engineer, I have to test the cameras and find the possible short fallings in order to try solutions and protect my fellow cinematographers in such a way, that when we will try to put on film (or digital) the collective work of so many people that are involved in the production of a movie, do not have surprises. Of coarse I don’t like marketing blah blah… because when the problem will arise I will be the one that has to solve it or workaround it. But let’s get to the chase… As always, when a new camera falls into my hands I do two things first I measure real resolution in a chart that has 2000 lines resolution like the ISO12233 to know, what the effective resolution is, and second I shoot a transmitive step chart from Danes Picta that has 28 steps of 0,15 neutral density chips a total of 14 f-stops. On the ISO chart, RED has surpassed my upper limit easily with 1550 lines of horizontal resolution. Measured with a 50mm Arri Distagon 2,1 in 4 aperture. I can upload the .R3D file for this measurement, but I thing the resolution that this camera has, is toping even 4K scanned film resolution, so it’s almost irrelevant to continue the discussion in resolution. Another thing that was a very pleasant was the absence of chromatic aberrations in the corners of the resolution chart… On the second thing, the step chart, I shoot it in a darkened room as its being evident from the photos, with a back light source of 3200K diffused. I was using 3200K in order to measure the worst case scenario and also it’s the same light that am using in all my camera tests. When we ware looking the chart with our eyes the darkest step was having a very easily noticing difference from the totally black carton board background. This is ensuring that the chart was correctly lightened. Also on the photos is easily understood that the camera wasn’t have any stray light coming from the board. The step chart is calibrated with error less than 5% on every step. Photo taken with flash Photo taken without flash This test is for evaluating what is happening into the deep dark areas, for that reason ignore the first 8 bright chips, in which the first it was just clipping. As you all know there’s nothing that can be adjusted on the camera in order to affect the exposure of the RAW footage. I only measuring released versions of firmware, so the camera was having the 13 version, which is the current release firmware. I know what beta means, that’s why I don’t want to play with beta versions… I used the 1,0,4 RedCine to export a tiff and a dpx in order to check out the headroom of the camera (Dynamic Range). That, to my surprise, was an adventure, every change that I made, even cropping or new white balance, I was getting different results, not to much different but different… After a while playing with RedCine and then with Photoshop and Brightness/Contrast in order to see what was visible on the step chart, I realize that I have to experiment heavily with the Debayering software in order to maximize the results and avoid the tweaking of every shot in RedCine, which is a nightmare. But I have to test the settings that are looking good to real footage and see the resulting real life image. Just in case, to avoid plastic effects… Since I don’t have the luxury of time to play that much and I don’t have the diversity of footage to do such thing, I decided to let in public the R3D RAW file of the reference step chart shoot and let all of you, that want to play with REDcine or REDalert to share with the forum your findings… A proposed work flow could be: Use RedCine or RedAlert and specific settings that you thing its best for maximum latitude export a 16bit Tiff or whatever you thing its best. Import the resulted image to Photoshop or any other software that will allow you to judge the latitude and noise levels (with Photoshop you can use Brightness and Contrast to expose noise and ND steps) Emphasies in the dark chips and ignore the first 8 brightest. Note that every one ND is ½ stop the chart has 28 steps (a total of 14 stops is available on the step chart) and the outer edge of the deeper step is in between the two bright (over and under) dots and in line with the right one After many trails find the best setting and try it to your real footage and see how it looks like. When you are getting in same conclusion post it in the forum to be shared with the rest of us. I hope the combined work of so many professionals will allow us to find a way through, to the new tool that is called REDONE and maximize its performance to our common benefit. I reserve my personal opinion for the time being. The link to the .R3D file the size is 67Mbytes .R3D 3200K TS28D step chart For reference am posting the links for three popular HD cameras that has being shoot the very same step chart in exactly the same conditions. Sony CineAlta F900R -3db HG3 Panasonic Varicam F -3db FilmRec Dark Compression Panasonic HVX200 0db Cinelike-D Any comments or suggestions are welcome. With respect to community,

David I understand, you are far away... In Greece from the 20 features per year that the local production is doing, 30% is S16, 20% is in 35mm and the rest is digital. But wait, cinema class digital is just the 1/2 of digital the rest is DV HDV and broadcast HD. All the features that being made with film are not making any money at all. The last big film was "ElGreco" I dont thing that has made the break even point... The commercial film production they have a budget of 400K$ and they selling at most 250K tickets. typical numbers is 100K tickets... Why they still using film? Because they want to be trendy... You know thing big... To rent a Viper or a Genesis or even an F23 is crazy dreams. So to cover the "thing big psychology" they using S16 which against 720p or 1080p is almost crap. And its crap because the labs are crap and the cameras are very old and not properly serviced (vary bad registration). So many features with HDW750 and of-coarse to be everything burned is art... I have printed 4 fetures with Varicam one of them went to Cannes in 2006 at the "saimaine de la critique" it was also listed in the Variety. The film was the "soul kicking" or "I psihi sto stoma" IMDB link In the International Festival of Thessaliniki when projected it was the best film-out ever seen in the festival, everyone was thinking that it should be film 35mm... In comparison with Cinealtas and 750 it was by far better. But not due to resolution, instead because of latitude and filmic texture. We have different perspectives in different areas of the world. my 2/3 of the film-outs they don't print more than 20 copies... Geof Boyle at a show in Paris has seen an unmarked projection and it was stating on a post at CML that Varicam footage was so good that was unbelievable to him and that HPX3000 was looking better than even F23 and RED...

David I have done film out of the ISO res chart in 4K raster in inter-negative and I personally see along with the Kodak guys the resolution on a microscope 100x and it was reaching the 1600 lines. We did a direct answer print to 2383 and we project it on a studio Kinoton projector with new lenses and the resolution on the center was 680 lines and on the sides 610. I shoot the same chart with Varicam > process it > film out on inter > answer print results: Microscope 700 lines, projection 680 and on the sides 610... Check the same on a big multiplex screen, the same results... If you do the same test with 1080p you will realize that you have to blur the image a bit at the end because it has to much sharpness. The famous story of "Pinocio". So for low volume distribution up to 1000 copies, for us that we are on the other side of the planet, resolution is meaningless. For big studio productions its another story, tooo... many generations... As for Digital projection... In Greece we have 2 or 3 screens... until we will be able to release locally a feature in digital, we need another ten years... Their is a madness around the world about resolution and none-one is noticing big issues like 5000K hard balance...

John Galt said: “More pixels do not necessarily create more resolution,” declared Galt, “but can harm overall image performance.” To explain, he recalled "a big argument with Japan" from his tenure as project leader on the group that developed the Panavision Genesis. “I argued vociferously for 1920x1080 RGB,” Galt said. “They were keen on building a 4K camera — which would have been one of the UHD 3840x2160 versions [proposed by NHK]. The main reason we didn’t do that is the pixel would get so small we’d lose two stops of sensitivity and two stops of dynamic range.” That’s because the size of individual pixels on a 35mm imager determines those stats — bigger is better because bigger photosensors can capture more light. Galt then mounted an argument for MTF (modulation transfer function) — cascaded across all components in an imaging system — as the single best measurement of “system resolution.” Determining the resolution of a film-based system, for instance, would require accounting for the MTF of a camera’s lens, the film negative, the interpositive, the internegative, the print, and the lens in the projector. The weakest link in that chain can have a dramatic detrimental effect on the final quality of an image. “Even if each of those parameters has a 90 percent MTF, the final system is only 53. If each parameter is 90 percent except for one parameter that is 60, the final will be 35 percent. “We have fallen into this trap of defining cameras in the context of 1K, 2K, 4K or megapixels,” Galt continued. “It’s only one parameter. The system MTF measurement is the only way to characterize a complete system. If the MTF is less than 35 or 40 percent, the image is going to be out of focus.” A working knowledge of MTF factors in a given system can lead to some important conclusions, Galt said. For instance, he estimated that a “good Nikkor lens” has an MTF of only about 30 percent at 4K resolution. “If you’re scanning film at 4K — unless you have extraordinary scanning optics — you’re wasting money,” he said." I don't remeber how many times I was analizing that subject on this forum and others. Thats why Varicam has that great DR because the pixel size are even smaller in comparison to the Cinealtas F23. Except from new F35 (Genesis) that because of the size of the sensor it has a similar pixel size... I have post this link that is an independed study about the resolution of theaters, numerus times... 35mm resulotion study Its evidend that the average resolution in our next door theatre is no more than 700 lines! If you print directly from the first intermediate a film shoot on 720p and a film shoot on 1080p will not have a difference that would be noticeable from the average viewer in a theatrical release. In my personal opinion from the 20 film outs and 2K DIs that Im aware of I cant see any difference. What I can see is the lack of latitude and shallow depth of field in some cameras. With Varicam I certainly don't have the latitude problem but the DoF is remain to be solved. I actually have something ready in a while that will surpass Pro35 by far and with NO diffusion look... Resolution is useful for very large distribution something like more than 5000 copies which is useful for the 5% of the total worldwide film production. And its useful only in order to make many DUPs certainly not for image quality reasons. Imagine that a Greek block baster has a distribution of 200 copies. It can easily printed from one inter-negative. So we don't need the extra resolution in order to be wasted for inter-negative > inter-positive's> and lots of inter-negatives again... just a straight print will cover the 99% of the features that we produce in our small country. I thing this is the case for the 95% of the rest of the world. Countless times I have said that scanning in 4K its a waste. Thanks god that a person like John makes a statement like that. If you search the internet you will find that John has this position since 2004 so its not a marketing move against RED. John Galt is Panavision Senior Vice President of Advanced Digital Imaging.

We do capturing a calibrated step chart (like Danes Picta TS28D or Stouffer 4110) that is ACCURATE REFERENCE TO LINEAR LIGHT and to emphasis on that, I own an X-rite 310 status A transmittance densitometer and I measure every step and correlated with the certificate from the manufacture and the error is less than 0,01D. In Imatest we are stating what chart we used exactly by selecting the chart type. So the target is ABSOLUTE PERFECT AND IS BEING CALCULATED BACK TO THE LINEAR LIGHT REFERENCE.- As for gamma curve... lets just use what the user will use in a real life project... And Graeme all the cameras are writing data either on tape or on disks, RED, because of the sensor, writes bayer data thats all. So please no more "data centric digital cinema age" marketing arguments... Again we are not playing marketing games here! Work with your camera to make it better, accept positive criticism, like the one thats on that thread, with no excessive aggressiveness from your side... Try to be humble, at the end it will pay back.

At last someone that understands. The question is, for a cinematographer, yes I have 11 stops but which of them are really useful? Signal to Noise Ratio, S.N.R. is the analysis of Imatest but expressed to F-stops not to db?s? And expressed to F-stops to be easily understood from cinematographers! That?s why the noise reduction and the correlation is resulting to better SNR or more useful range. Some where I read that the sensor is hard balanced to 5000 Kelvin, that can be another cause of problems, since interiors with 3200K will be more noisy? unbelievable!

Joofa I would like to know your full name also and your occupation, but beside to that you are doing a very good but deeply technical analysis that I understand it fully. To add something in the mix for John and Graeme, The way that this method (of measuring DR) is working, is that we expose the image just before it clips the brightest step, this is between 98% to 100%, so there are no photons that will allow a hard clip since there is NO clipping in that way of image exposure. All the brighter steps especially the first 1/3 are noiseless on almost every camera? So what we actually analyze is the dark steps. These steps because of the nature of the measurement are very sensitive to noise reduction. In reality there is a limit, there are steps that don?t trigger at all the sensor so on these there is no data and those steps are the absolute limits of the system (sensor/debayering/curve). But what is usable is what matters to a Cinematographer, so the rest of the steps that have some info, as heavy the noise reduction is, that much Imatest is reporting better results, but to a point. That point is the absolute limit of the system that I described just above. That point yes Graeme it doesn?t change. But to get better results with means of changing the EFFECTIVE noise reduction, yes you can make the result to look more in favor or less favor. As I have said in the past you can also go to Photoshop and hand paint the steps, which will give you the best results. This is not the point. But we are not playing games here. The point is to get an image AS IT GOING TO BE USED BY THE USER. And then measure it, AGAIN THAT?S VERY SIMPLE.

Yes Keith, RED camera is using CMOS Bayer pattern sensor so if you read carefully the theory of it you will find that: ?Since each pixel is filtered to record only one of three colors, two-thirds of the color data is missing from each. To obtain a full-color image, various demosaicing algorithms can be used to interpolate a set of complete red, green, and blue values for each point.? From wikipedia So demosaic or debayer algorithms are manipulating the RAW image data in a dynamic way in order to give the best results. This can?t be described as lossless process when it?s compared to a 3 CCD sensor or a Stripe array sensor like Genesis has or like Foveon, in which you have all primary colors and resulting RGB image directly from sensor. Due to the nature of the Bayer pattern sensors it?s unavoidable a sort of noise reduction in the process. If you have basic knowledge of how a Digital SLR is working with RAW converter (for Bayer pattern CMOS sensors like REDs) software like Capture one, you will know that there are a myriad of parameters like sharpening, noise reduction, curves etc. that intervene to the final image. Graeme quote: "I put a curve on it, and the software Imatest now tells me I have more DR. No I don't. I have the same amount - the exact same amount I started with. I put a different curve on it, and the number goes up again." So for someone like Graeme to claim that kind of problem with the use of Imatest is quite odd. He can always use a typical curve that his end user will use like REC709 or REDLog, its very simple. Since I haven?t seen his final word I will keep a ?wait and see? position. As for your idea, I thing that?s a useful test tool for on set real-time evaluation, but I don?t thing that for laboratory use will be compered to a tool like Imatest. But Keith the subject of that thread is not ?methods and tools of DR measurements?? So I will stick to the subject and wait for a reasoned respond from Graeme. And why not some other qualified persons from the community to pose their opinion?

Graeme OK, I will follow your thinking? When I try to emulate what you are saying with cameras like Varicam and Cinealta F900R I can?t change the results of Imatest. So with all other cameras I can?t reproduce what you are saying. Why? Because your camera is recording RAW data, that means your software is doing the debayering, the subsequent noise reduction and the unavoidable sharpening according to a given curve. Right? I thing yes more or less? Every time that you give to your software (Red Alert, REDcine) a different request (see curve, sharpening, gain ASA etc.) in order to create a new output from RAW, the internal algorithms are dynamically adjust the parameters (Debayering strength, Noise Reduction, Antialiasing etc.) in order to produce the best result. Right? Again I thing yes? That effectively, IS CHANGING the results of Imatest, you should aware of this long time now. All the other cameras are not having that RAW/Debayering need, that?s why I can?t reproduce your findings? Even thought in all the other cameras we just do the following: 1. Open the box put out the camera. 2. Turn on camera. 3. Do a black balance. 4. Selecting the BEST PERFORMING SETUP according to manufacture data or use the settings that you typically use with that camera on real projects. 5. Adjust the white balance point to the appropriate Kelvin of the light source. 6. Point the camera to an appropriate transmitive step chart target as numerous times I have described. 7. Grab JUST ONE frame (not many as Keith has understand). 8. Export it in 16bit Tiff 9. Analyze it with Imatest. That?s it. So, setup a RED camera as it will going to be used in a real shooting project and according to the above steps. Choose the real settings that you going to use on a real project, export the tiff frame and analyze it. Better, choose your best performing settings and do the export? analyze it. That IS your camera performance? Graeme from your work, I have understand that you are a very good engineer, why can?t you understand all that? To compare two cameras, we simple use the best settings chain on every system and we analyze the results. What is so difficult to understand? Imatest is stupid software that doesn?t know what?s RED and what?s Varicam. It just analyzes noise figures. As for using Imatest to guess what the gamma curve that you used is, I don?t thing that Imatest was designed to do that. So don?t expect accurate results on that. But this is not a correct argument in order to trash the usability of Imatest. On DR measurements expect very accurate results ? Keith, Imatest is analyzing in a single frame the noise levels on a specific ?ND level? by measuring the mean deviation of noise in that step. It translates the noise level to relative F-stop level. Then is counting how many steps are visible with noise level i.e. no more than 0,1 F-stop. Converts the counted steps to F-stops i.e. 28 steps visible with noise level no more than 0,1 F-stop with ND 0,1D per step equals ND 2,8D divided by ND 0,3D (which is one F-stop) equals 9,33 F-stop latitude with very low noise level. How low noise? Less than 0,1 F-stop. That expression is closer to be understood by a cinematographer than the i.e. SNR -56db? So Imatest reports five levels of quality or how many stops with noise level: ?Very good quality?________High________< 0,1 F-stop noise level ?Usable quality?___________Mid-High_____< 0,25 F-stop noise level ?Very problematic quality?___Medium_____< 0,5 F-stop noise level ?Very Bad quality?_________Low_________< 1 F-stop noise level ?Crap?!?_________________Total________all visible steps up to 5 F-stops noise ceiling I thing this is the most cinemagrapher friendly approach to the DR/Latitude measurement problem? and its politically correct for an engineer, is like common ground for the two professionals (cinematographers and engineers). All the graphs are for those who can understand them and they exhibit very critical quality details that are crucial for a DIT or an engineer. Keith I strongly recommend you to go and read Imatest how to in order to understand better what am talking about.

Jim and Graeme, It?s easily understood that if you give different image you will get different results? Even my four years old son knows that different actions have different results? So please stop repeating that argument. If you really want to have accurate results, then take a shoot, pass it through your red alert, in a way that you will not alter the original curve (there must be same kind of original curve in the RAW recoding) export 16bit TIFF, and this is it, you are ready? Don?t forget to tell us what is that curve in order to be able to verify it independently and am OK. Alternatively if you don?t accept Imatest for your personal reasons, PLEASE DO SHARE with the rest of us your internal tool in order to be able, all of us to have a way, to compare your CAMERA to the rest of the cameras? But you should have to note, that this tool to be accepted from us it has to have a generic input like TIFF and not a special for RED? Jim, all the rest is just monkey business? If you don?t want things like that to happen then don?t come forward and engage with people in small talking. There are consequences, that?s why Sony, Panasonic and others don?t coming forward. If you thing you are brave, you have to withstand the pressure and be OBJECTIVE AND HUMBLE with your product. Or stay in the shadow and let your camera to speak by itself, read everything, analyze it, and act. Then your ACTIONS will be accepted and praised. Graeme, our time its also very precious, so if you think that?s a waste, stop answering posts EVERYWARE! Phil, John, the step charts are created from monochrome positive film, the charts are coming together with density measurements, that verifying the accuracy of every single step, so in this way there is an absolute stripe of NDs from clear to ND 4,20D. A stop is 0,30D so 4,20D is 14 stops? And because they are back light it?s easy to create an even light. The step charts are very useful if you playing with your camera, because they immediately allow the understanding of the results of your action.

Graeme, my problem is that few months ago we ended that particular discussion in the hard way, by Jim coming forward and post a seizure of discussion in the DR ?issues? that arise when I picked up the test Adam did. The post was something like ?I don?t allow Graeme to talk about that matter any more!?. That was probably because our engineering discussion didn?t have good marketing results for RED. Or at least this is what I understand, from His act. I perfectly understand His position and I didn?t continue any more since it was obvious the problem you had? This is one thing, but having the nerve to argue with a poor 1st AC that happens to post his humble personal adventure with THE SAME IMATEST PICTURE that force Him to seize our discussion back then, its another thing? You guys at RED, must decide, do you accept Imatest and transmitive charts as a basis of discussion for DR measurement or not? Because I see The Boss using Imatest to point to a poor guy (and to a community of cinematographers that is listening without being able to properly argue) that his camera performs 11,4 stops and on the same time the lead engineer on the first real conflict with a real engineer tries immediately to depreciate the case by doing the classic FUD movement. Jim and Graeme PLEASE talk to each other before posting, you are not alone? JIM, BEWARE, WE ARE NOT IDIOTS! Yes I know it was a bad coincidence (for RED), that I did read, that thread, this morning? I?m hoping after all these, RED to be a better camera? and not all of us to be better (forgiving, tolerated) RED users? The cameras should serve cinematographers NOT the vise versa! Back to the engineering discussion? Stephen, Max and others I?m willing to pass through my Imatest software a still frame (Tiff) shoot from Viper, F23 and others from a Danes Picta or a Stouffer transmitive step chart properly lighten as imatest is pointing. The chart is very cheap Stephen, Danes is from Czech Republic and it cost something like 50euros. Danes Picta TS28D is the chart and it?s calibrated in 28 steps of 0,15D a total of 14 stops. For US residents Stouffer is T4110 with 41 steps of 0,10D a total of 13,6 stops. I use Danes. It needs a black carton surface to hide the back light, a diffused light source like a four lamp Kinoflo and a darkened room. First do a black balance and then adjust the white balance of the camera to the white point of the Kinoflo, then adjust the iris with the help of a waveform monitor to reach the brightest step the absolute top of the waveform, capture a 16bits Tiff frame with no processing, send it by email to me and I will reply with the analysis? That?s it, simple and easy. Now where, Graeme found the difficulty of that process I don?t know. Probably to have good results, needs a lot of tweaking in the curves who knows?

Graeme, I have no comment on the color of your face? but the image that?s being published and used in this thread is from your web site and it was your BEST effort in terms of curves and noise manipulation, even so they simple can?t be compared with a stupid old camera like Varicam F? don?t mention HPX3000 or Viper? Don?t go to your B plan immediately and try to depreciate my argument when there is no other way to fight it. You are a very good engineer, and you know good guys sometimes are making mistakes to? So stick to your A plan and stop trying to convince me that the sky is RED, just try to fix proper latitude to your camera, starting with a new better performing sensor because resolution is not everything, color and latitude IS everything. Don?t be another marketing resolution victim? All the Oscar?s awards in our resent history of cinema went to movies that we see in our local theaters with no more than 750 lines resolution (or much less)? Didn?t we laugh with them? Didn?t we cry with them? Didn?t we respect them? The scenario, the acting, the directing, the art of photography, the colors and the light are magic, NOT resolution.- (Except if you make cameras for military espionage satellites?)

I have updated the table in order to include Graeme chart. I can't accept that chart since its not independently captured and processed. Regardless to my personal objection I have included it in order to be easier the comparisons. Graeme I'm aware of your objections but please don't claim 11,5 stops since there aren't visible even with Imatest. Stephen there is more to it, the DINSTICT steps are just 28,2 so 28,2 x 0,333 = 9,39 F-stops and the rest are INDINSTICT steps (not clearly visible), but the software, due to the advanced algorithms Imatest is using, can see deeply into noise and can report up to 11,4 stops. (the 0,333 F-stop is for 0,1D step for Stouffer in contrast of 0,15D or 0,5 F-stop Danes chart) If you compare that to the Varicam results all the steps are visible clearly up to 12 stops. In addition to that, there is a clear saturation in the latitude behavior of the camera around 9 stops. It seems that the sensor (or the post processing on the DSP) is so pushed to produce latitude that it has no headroom above 9,5 stops and that is evident also in the Adam Wilt test. The only difference between Adam and Graeme is the blue channel noise reduction; all the rest is almost similar. Its also evident the fatigue of the latitude from a point on, that the noise curves is climbing very aggressively. Varicam F goes up to -4 Log exposure with no more than 0,9 noise and RED cant reach more than -3 Log exposure with almost double noise levels, above 1,5 to 2,0 ? And still I haven't test Viper or Varicam H or HPX3000 or even F23. The -4 Log exposure is equivalent to 4,0D Visual density in the blacks.

Zac the essence of my message was: Look the performance that?s above ?mid-high?? I?m posting a more digested version of the summary? So now I thing its better... Green is better red is worst. Now see what Jim showed to us in his post: Its easily understood that the camera doesn?t have 11,5 stops of usable latitude... That?s my two eurocents, dude's

Hello guys Just to add some engineering point of view here. I was the guy that used the Imatest in this forum first and I pointed out it as a DR measurement tool. So I have a responsibility to clear up few things? If someone reads what the Imatest numbers meaning, he will easily understand that the maximum USABLE latitude could only be ?mid-high? in which the noise level is NOT more than ¼ of an F-stop. Above that level everything is almost a crap, so ?mid? is half a stop noise and "low" is ONE FULL STOP, I don?t won?t to mention the "total" which is 5 STOPS of noise level!!! So what Jim is actually saying is that the camera has an EFFECTIVE DR of 9 and ¼ F-stops!!! In the mid high range. NOT to mention the excessive noise reduction which is evident to his screen grab, the curve is almost vertical in the noise spectrum? So where in the hell did he see the 11,5 stops? Except if we consider the 5 stops of noise an acceptable level? An old Varicam F can have the same numbers with NO noise reduction!!! If I use noise reduction, I can get up to 10 ½ in the mid high level but with a noise spectrum as vertical as RED has? but this will create plastic faces? and David will not be very happy. If someone is in interest, see my objective latitude test that I did back in September and notice how much steeper is the noise spectrum curve (that Jim is pointing) than from all the cameras I have tested? The noise curve is the bottom right curve on the Imatest report picture. The link is http://www.motionfx.gr/files/Latitude%20Ob...son%20Sep07.pdf David, what an engineer is trying to do, is, to maximize the performance of the tools an artist is using. In order to do that, it needs an accurate method to measure the results of his efforts. There for an artist should put the minimum of his time to really understand what an engineer is trying to tell him with his numbers. So please read slowly what am writing and try to understand what am saying, probably there is some helpful information hidden in our efforts. A humble engineer?

Probably you didn?t read the full contents of the links that I send In the http://www.imatest.com/docs/q13.html Go down to the middle of the page and read the Dynamic Range measurements?

Keith probably I didn?t explain well or the language barrier? The step charts are NOT REFLECTIVE and yes, you are correct, reflective test charts are totally wrong in DR measurement. The step charts are TRANSMITIVE they don?t reflect the light? Its like an array of Neutral Density filters that has being calibrated with a densitometer to have exact steps of 0,15D or 0,10D status A and they allow to pass the full visible light spectrum like normal camera mounted ND?s. LED?s do NOT transmit a uniform full spectrum light. That?s very crucial in DR measurement because sensors are not having the same behavior in blue for instance, so if your LED?s are not calibrated with a Spectrophotometer and a Light Spectrum analyzer you can never be certain on the results. You have to have a flat spectrum light source like an array of diffused dido tungsten light as a BACK light (that?s because the step charts are NOT reflective) for the step charts. More over the LED light is a point light it?s not an area light so it?s very difficult without a diffuser to make a judgment in a so few pixels about the noise? In order to make your LED array so accurate in light spectrum and so diffused that you can measure accurately DR I thing that you will spend more than 1000 dollars. I?m an electronic engineer and I know what am saying. ?There is also no way you could accurately view 12 or 14 stops of a linear grey scale on a waveform monitor. The only thing I am interested in is how many of the square YAG fluorescent crystals could be clearly seen on the monitor screen. Which is all that counts really!? That?s why I suggested you to use that software in order to see the hidden info in that range. The waveform is needed only to adjust the aperture. The Cinematography class cameras are having totally different ways in image recording than typical Broadcast cameras, for instance Varicam and F23 are recording Log encoded images that need special processing? So monitor observation is good to a certain degree, certainly not to a Cinematography class?

I?m just getting everyone back to the topic? Keith this is a nice Idea? But the problem is that you can?t evaluate the noise in all the steps (as you point in your message) and with the waveform or a monitor you can?t see information that?s hidden below a point. The correct method is, just to buy for 84$ a Danes Picta calibrated step chart like TS28D that has 28 steps of ND?s with ½ stop each reaching a range of 14 stops The web site is : http://www.danes-picta.com/txt_PhotoDigital.htm Or alternatively you can buy a Stouffer T4110 step chart with 41 steps of 1/3 stop a total of 13,6 stops for a bit more dollars? The web site is : http://www.stouffer.net/TransPage.htm Put the step chart to a black carton sheet in a way that no light passes from the edge of the film, so only the steps are visible, back light it with a diffuser in a darkened room in a way that the back light is not lighten the room or the lens of the camera. The level of light should be in a point that you can discriminate, by naked eye the darkest step from the carton black sheet. Use a waveform to adjust the aperture in order to have at the top and just clipping the brightest step. Record few frames. Capture uncompressed 10bits few frames of the recorded footage, use software like Combustion or After Effects in 16bit mode to export a frame in TIFF 16bit format. Then buy for 199$ a software that is a great tool for all of us that we dealing with photography or cinematography in order to assist us in measuring scientifically and evaluate our hardware. The software is the IMATEST. It measures system MTF, tonal response, noise, dynamic range analysis, veiling glare, chromatic aberration analysis, calculate distortion for 3rd and 5th order polynomial and many other aspects of what we do. The web site is : http://www.imatest.com/docs/q13.html The total cost of that set up is no more than 300$. And it?s quite scientifically accurate. And I thing its inexpensive compeered to the LED method? This set up allowed me to do the following tests back in September 2007: http://www.motionfx.gr/files/Latitude%20Ob...son%20Sep07.pdf Check out the graphs and you will realize that a simple evaluation in a monitor or a waveform it?s not good enough, the approach that Mr. Norman Koren follows in Imatest is giving immediately an answer of the level of DR quality that the camera has. By splitting the results in High quality DR (noise level less than 0,1 of a stop for the given step that measures), to Mid High quality DR (noise level between 0,1 and 0,25 of a stop), Mid quality DR (0,25 to 0,5 of a stop) and Low quality DR (0,5 stops to 1 stop noise). In the past I have propose the Imatest workflow to be a reference in our measurements, but it didn?t had much of acceptance my proposition, probably because will make some people to sad?

Jamal Use our relay and the 2/3 to 1/3 converter from JVC: 2/3 to 1/3 adaptor There are also for 1/3 to 1/2... Regards,