Sorry John, been a long time. But if you have a look through he original adaptor threads they explore condensers for their projection screen adaptors, similar but in this case there is no screen and the condenser is one suitable to take the image from the lens. They link to a number of Optics science sites in those threads, that discuss things. The thing to watch out for (apart from bad ones that will give you various chromatic and lens aberrations) is that triplets generally are designed to correct for two primaries and either the IR or UV range, instead of three primaries. Such a triplet that corrects for the three primaries are usually ,ore expensive (hundreds even).

Now on the other side, one of the threads I posted on is an old one from virtually before the SLR adaptor thing took off. A guy on the short thread has a commercial Canon SLR lens adaptor for his XL1 that has a condenser instead of the normal hollow tube. He reports much brighter images. So it will be a thread from 2001-2003 that has XL1 and me on it, so an advanced search should find that, I was only on a couple of threads from those days.
rear screen adaptors

Wayne -- thanks for the Condensor info: I'll try and follow this up next week (I'm editing a short film at the moment).

Noah -- I rediscovered a company here in the UK which I dealt with many years ago called SRB Film Service. They sell branded filters and a huge range of stepping rings, including some they make themselves. They also make custom one-offs for you at a reasonable cost. Check out their website and if you can't see what you need email them your requirements -- they might be able to solve your IR filter attachment problem.

www.srbfilm.co.uk

Regards,
John.

Ok, remember how I said sumix's IR filter was kinda crappy? I just noticed their website had a new updated pdf on how to correctly use the IR filter. I thought, perhaps they are reading my posts and this is their indirect response to my complaints about their filter, i dont know. Anyway, it made me think maybe i just dont know how to use the filter correctly, so i set it up again, screwed it in and tried it out, and it wasnt as bad as i remembered. Granted, I still have problems with the backfocus distance, but I suppose i just need the right size washer to wedge behind the lens so it sits in the right place. Anyway, I tested the camera in a few configurations, with the rear filter sumix gave me, with that rear filter and the one that came with my computar lens (its not that good), and then with the sumix filter and my big b+w UV/IR filter. I will try to post shots to illustrate the difference, but basically its no good without a filter, much better but not amazing with the B+W filter, and then really not much worse with just the rear filter. Cosidering my difficulties with mounting the front filter, I will for now stick with the rear filter and try to find a way to adjust the backfocus. This will be a problem for my nice schneider lens since it doesnt actually fit in the c-mount all the way with the rear filter in. The schneider lens protrudes a lot past the cmount threads and that protrusion moves in and out relative to the threading when the lens is focused. maybe this will be ok with a spacer or maybe if i can figure out why the heck the last piece of glass in the schneider lens can be screwed out since it might fit if i just took out that part of the lens, but im a little afraid to mess with it.

That's good news. I'm looking forward to some new tests.

I've been doing a few tests when i had free time. John's plans to play with Sumix's standard application inspired me to look into it a little more. It's not such a bad application. Saving directly to avi is still not really a worthwhile function because i tried it a few times and it recorded at a framerate about 1/4 whatever I had the camera running at at that time. Saving to RAM (which saves to available ram and dumps it to a .smx file), on the other hand, isnt so bad. Given you have enough ram (i had only enough for about 8sec of video), it maintains the framerate well without dropped frames and when converted to avi in the smxview app, it saves the effective framerate in the avi so it should play back realtime (although its unclear how accurate that is). it doesnt use the microsoft vcm to allow you to choose an avi codec, so you are stuck with uncompressed rgb which could then be converted to something more efficient.

I've been looking at things like gigabyte's i-ram or solidstate disk raids (not unlike P2) to remove disk access lagging. I wonder if saving to a ramdisk would be as efficient as saving directly to memory (memorystream in .net) or if my lag is a problem with the filestream.

Not to much better (goes through the PCI bus) unless something is wrong, as the streaming to disk should be very streamlined by the hardware in parallel with your capture already, so slow up take speed of data by disk should not effect it (there is another possibility, if it is accessing memory a few bytes at a time to dribble it to disk that would severely break up memory performance and degrade overall performance, but I doubt in this day and age that this would happen).

So, yes it could be great, but if it is, something is not optimized in the software.

It is probably worth asking Sumix, and the manufacturer of the software, to help sort this problem out with you (streaming Bayer to disk and preview displaying at the same time). They will have the know it all expert programmers (if Sumix doesn't, the software manufacturer should). Maybe you could swing some work out of it,. They must be missing lots of sales because they don't ship their software with a friendly video capture application as standard (hardware needs 12 bit dual slope packing at minimum, head memory buffering, and even compression, which they were working on and direct to external disk caddy recording).

I just remembered something about these cameras that could affect performance, even though they have a set average data rate, unless the head has memory buffering the frame read out comes out in spurts around blanking and other operations.

Noah -- RE Schneider lens problem. I got some C-mount info from Schneider concerning their "older manual iris lenses" as they referred to them in the email. They list the 17mm Xenon f0.95 as a 2/3" format C-mount lens. They don't list a 1" C-mount at 17mm focal length (according to them for 1" it goes: 10mm, 16mm, 25mm, 50mm etc). When you say "the last peice of glass in the lens can be screwed out" I'm wondering if this is in fact a 2/3"-to-1" adaptor? If your lens-front IR blocker performs the same as the between-lens IR blocker, you might prefer to go back to using the lens-front one to avoid the Schneider rear element protruding into the between-lens blocker? The 17mm Xenon should have a filter thread diameter of 35.5mm (?). Looking at the range of stepping rings available from SRB Film service, you could make a light-tight connection for your lens-front IR filter using two stepping rings: 35.5mm to 49mm (special SRB ring) then 49mm to 62mm (standard ring). Standard rings cost between £4.90 - £5.50; special rings between £8.70 - £12.95 (I don't know what charges for overseas shipping).

John.

Yeah it's definitely a 2/3" lens but im not sure why it would have a 1" adapter, and I tried removing that piece of glass only to find the image was not focusable or usable really. That element does seem to focus the image but I think if it is inteded for adapting with another format i dont think its a c-mount. anyway for now i will use other lenses and I need a spacer to increase the backfocus distance anyway which might fix the problem if it gives the scneider lens more clearance.

Sorry i wont be able to make many updates for at least a week, I'm off traveling in France a little.

As for ordering parts overseas, i havent heard good things about recieving packages in morocco (and i dont really even have my own mailing address there). so hopefully the rear ir filter will do what i need for the time being.

Noah -- as far as I understand it 1" is the standard form for C-mount, with 2/3" and 1/2" being smaller off-shoots. I believe the Sumix lens mount is 1", therefore if the 17mm Schneider lens is 2/3", then the 1" adaptor is definately needed for it to fit the camera. I was wondering though if it's the adaptor which projects further back (into the IR blocker) than a "native" 1" C-mount lens would? Buying second-hand C-mount lenses for box cameras can be problematic; I've found it difficult to get information on different brands (like Angenieux or Bausch and Lomb) to make good buying decisions. Perhaps I should start a thread to post what info I have (which isn't much), and this might encourage others with knowledge of these lenses to contribute and build a useful resource?

Enjoy France,
Regards,
John.

I wasnt aware c-mount came with any sensor/film format specifications. I have seen plenty of c-mount lenses for everything from 1/3" (although thats usually CS) to 16mm and 1". From what I understand c-mount only relates to a backfocus distance and a screw thread spec. I really dont think the single piece of glass in my schneider lens is a relay lens that converts its image coverage to allow the same field of view in 1" and 2/3" formats if thats what you mean. In general c-mount lenses just are rated 1/3,1/2,2/3,16mm,1" to tell you what the largest size sensor you can use without vignetting. All lenses intended for different sensor sizes still fit in the same c-mount, its just a matter of wether or not you are using the full coverage of the lens. Or are you referring to something else?

Noah -- I thought when an adapter includes an optical element as you described, it suggests that the adapter is involved in redirecting light because of the difference in original coverage, though I'm probably wrong about that. I've started the new lens thread called "Call for C-mount lens info", so maybe we can find out more about these great little lenses if others join in.

Regards,
John.

Sorry ive been bad about updating lately, I was traveling and hadnt made any significant progress. But to update whats going on with my camera, Sumix has sent me the spacer I need to fix the backfocus on my lenses with the behind the lens IR filter. For now I've decided that IR filter is enough (my computar lens actually came with another IR filter so that improves the situation a little). Neither nor both, however, are as good as the B+W IR/UV cut filter that i cant get to mount on my lenses.

I've been working on the program a little, I intended to test audio/video recording at the same time to test whether the camera's framerate will allow it to sync with audio, but i found that my computer just cant really handle doing both at once. This in turn has turned me toward focusing on ram recording since that may be required to reduce cpu usage and data writing lag and since I know i want to eventually end up with resolutions higher than 1024x576. Just today I finally picked up my camera handheld and recorded some shots to check out the rolling shutter artifact. Unfortunately it reminded me rolling shutter could be a big problem depending on what i am shooting. I think I might try to play around with some settings a bit and post some videos and see if people here can give me advice as to what is acceptable in terms of rolling shutter artifacting. I will keep looking further into using blanking instead of sumix's built in functions to control framerate, since it seems likely those functions are not at all written to minimize rolling shutter issues.

News?
 

Noah - any news on your project? Have you shot any more tests with the M73 camera? Rolling shutter and RAM recording results would be of great interest...
Regards,
John.

Hey I'm glad there is still some interest. I have been working on the camera on and off, but really not much lately, although I did get adapters to allow me to mount my IR filter on all of my lenses, which has so far given me good results. I have been experimenting with rolling shutter a bit, but have come to the conclusion, its not great but it will do as long as i set framerates myself. If the siliconimaging HD camera runs its rolling shutter only twice as fast as its framerate, I figure that should be good enough for my camera. this means I should be able to handle a ~20MBps data stream at 24fps. (~40MPps performance at 48Mhz, i think this has to do with minimum possible horizontal blanking limits and control data overhead, the sensor's manual seems to confirm this somewhat, but I am still not sure why my actual pixel rate seems so hard to calculate, although it is consistent) Maybe some more if i allow a little more artifacting.
Actually the main thing i have worked on lately is the LUTs, which i find to be very cool, since I can get an 8-bit log image out of my 10-bit hardware. This means more highlight latitude (subjectively) and more apparent light sensitivity. Of course 10bits linear isnt a ton to start out with but its nice to have so much control over it.
Another thing that interests me is when I looked through the micron manual, its exciting the amount of control that an be had through register programming. I hope to get into this since sumix supplies functions that allow access to the cameras registers. for example I might be able to do horizontal line skipping to get an anamorphic image, so that i could get a 960x1080 anamorphic image that uses (nearly) the whole area of the chip and is very compatible with 1920x1080 HD and fits my datarate requirements. This wouldnt be too different from the imaging of the FX1/Z1 (except mines 1/2", 24p, uncompressed dtd, 8bit log, with better faster lenses, and cheaper).
Anyway, there isnt a lot of time to work on this lately and my computer has been acting up (it seems moroccan electricity may be damaging to computer equipment) but i want to at least try to get some nice handheld test footage off the balcony of my new apartment. I also now have a new website to post it on. I'll let you know when that happens.

Hi Noah,

We're way over twice the frame-rate for the rolling shutter . . . while double is good, we're clocked much higher than that.

I think people are still subscribed to the thread, but we are just waiting to hear from you.

Jason, sorry, that was just what I gathered from the siliconimaging forums, Ari had told me that you were running at twice the pixelrate and capturing every other frame, which I imagine would lead to a rolling shutter difference of half a frame length, no? This made sense to me since I figured the camera runs at 75MHz or so which on an altasens translates to 150MP/s which would make sense for 12bit 1080/24p (~75MP/s). You're saying the silicon imaging camera actually runs at over 150MP/s? or am I missing something? I thought the altasens couldnt go past maybe 85MHz max.

Quick update:
I finally got around to playing with sensor registers directly through sumix's API. They do not provide any documentation on it, but it turned out to be surprisingly easy to do, and I successfully implemented anamorphic imaging in a matter of minutes (and after bugged sumix so much to implement it in their software). This means I can run at resolutions like 2048x1152 using the full frame skipping every other column to get a squished 1024x1152 image that is much easier to deal with in terms of data rates and using extra pixel clocks for vertical blanking (cutting down rolling shutter artifacts) . Anyway, I am excited about being able to use the whole size of the sensor and be able to run at resolutions compatible with 2k and 1080p. I've also been able to optimize the recording algorithm a bit, but still not enough to get more than 960x540 to disk at 24p with my slow slow processor. I am getting excited about my plans for upgrades, I got the idea to build a modular computer system that folds out to fit in a suitcase for a mobile editing bay and that folds up to about the right form factor to run on rails with my camera head for handheld work. I'll take some shots with the camera in the next week and post them on my new website, and I'll be sure to add updates when i return to the US and am able to start building my new and improved computer end (should end up being compatible with the siliconimaging camera head, just in case ever get enough money to afford one and get tired of working on my own camera)

This isnt anything totally new or special, but I have a video now posted:

http://www.noahyv.com/videos/01_01_01_01_xvid.avi

Let me know what you think and if there are things I am not seeing that needs to be worked on. For one, its at 960x540 which is still a bit too much for my prototype 1ghz computer for the camera(you can tell since it drops one or two frames), in the future ill probably just post 720x540 videos until i upgrade my system. Also note this is a compressed representation of uncompressed video, so any compression artifacting you see are not issues with the raw video I am capturing, just the xvid compression. Note the gamma curves which i've implemented based on some film log response curves. This was shot with vertical blanking set to more than the vertical height of the frame so any rolling shutter artifacting in this video will probably be less than when I run the camera capturing a larger frame resolution.

Just curious, but will that create aliasing artifacts when you un-stretch the image? I'm assuming optically there will be "gaps" where those columns were suppose to be, so it's not exactly the same as using true optical anamorphics is it?

BTW, Your video looks great!

You should think about using a new Core Duo setup with the Yonah or Merom procs . . . there's a ton of processing performance on those machines (I mean we're doing a bunch of real-time signal processing AND CineForm compression at very high resolutions on these procs).

Yeah that is definitely true. I have thought about that, and the sensor manual says that is supports binning (reading extra pixel quads and averaging them), but I have not gone that far into it and do not know what impact that would have on the pixelrate. I would imagine it is less aliasing than i have seen running at full 2x skipping (im pretty sure sumix's standard binning is just skipping).

Actually I have settled on a mobo and proc, i plan to go with the core duo and the ibase MB899F motherboard. Jason, any guess on whether that is compatible with the silicon imaging camera? The question is just the gigabit ethernet controller i suppose.

My suggestion if you want a mini-itx mobo that's ideal for the SI camera would be the Aopen i945GTt-VFA.

Now for our camera, if you can wait for Merom, I'd do that (overhead is always a good thing) . . . of course you could always just add a Merom later.

DDR2-667 is also must (compared to DDR2-533), and it's compatable with this board.

http://global.aopen.com.tw/products/mb/i945GTt-VFA.htm

Thanks for the suggestion, does that support HDTV component out, out of the box? I just liked that the other one i was looking at could support DVI, HDTV, VGA, TV and has full size ram modules (which may be more available and better value). Is the aopen board what SI is using for their setup?

The Aopen does support HD component analog output out-of-the-box.

I would highly recommend it.

Noah -- I've ordered an M73. Hoping to familiarise myself with the software having the camera connected to my dektop, later will buy a laptop. I'm looking around for an Angenieux 15mm lens, but have a Pentax K/C-mount adapter to use a 28mm SLR lens in the meantime to start some tests. I'll keep you posted on how I get on. I believe the software is capable of recording a still image sequence, and I would like to experiment with this at 25 pictures a second (at whatever frame size works within the various bandwidth limitations).
John.

Pity more motherboards do not have component in as well, apart from some of the VIA ones, just a few cents/dollars motherboard costs, not $1K. Pirates have really blown it for the rest of us, and played us right into the hands of manufacturers.

John - Wow good luck with your project, I'll be very interested to hear how things go for you. It sounds like you are just using their camera application? I would imagine the 25 still frames per second is a pretty big limitation since I dont think it will store those in RAM like with the RAM capture option, and even with lossless TIF (which they now support), youre looking at some pretty high data rates since BMP and tiff i believe are RGB so that triples the data right there, and the cpu requirements for real-time lapacian debayer seem pretty high especially for more than SD res. But i suppose a nice dual core cpu and a fast HDD might be all you need.

Wayne - Actually I've been surprised to see component HD out on quite a few motherboards especially with the new integrated intel and nvidia 6150 gpus. I'm not sure I get what you mean about pirates. Do you mean people pirating movies? I would guess it probably has more to do with demand.


As for my progress, I'm finally back in the US and getting back to work on the software. So far my tests are good, less cpu utilization with my faster computer i left here, looks like i may need to change my disk writing method again since ive been using a little test program to try different methods of writing data and it seems .NET filestream can get 52MBps on a linear write as long as i dont give it more than 256KB to write at a time (weird, huh? maybe a disk cluster size thing... it benchmarks only about 30MBps running one 1MB write operation and 52MBps with 4 separate calls to write 256KB). I think I will play with non-threaded writing more and hope that will give me good results with this new revelation. I wasn't too happy with my many-threaded disk writing implementation anyway, it was great at avoiding dropping frames on my slow system but when pushed too much no good at writing them in the right order and I dont think im programmer enough to fix it right now :P

I meant component in for recording from cameras. I wish they would all go to HDMI now, and HDMI in on the motherboard. 10.2Gb/s, HDMI 1.3 (upto 16bit colour and mega resolutions) would make an excellent camera head interface, it has the digital structure that could be made to handle head commands. I would like them to replace short haul network, USB/Firewire, hard drive and VGA with HDMI, it would make an excellent data interface (please note, the extra cost limitation for slow cheap devices can be over come by having the interface conform to lower data rate USB/2.0/go version (automated requiring little CPU interaction, like firewire) standard for these devices, and repackaging the data stream at the hub. What a beautiful world that would be, don't matter how many ports you have on your computer you can simply plug anything into anywhere and it will instantly work. It could even replace many forms of PCI, and even the external PCI express desktop bus (what happened with that).

Noah –- you’re right: single and sequence still image recording to HDD (using the supplied software) is a simultaneous conversion to RGB, and therefore very heavy on data rate. Since my desktop is faster than my expected laptop (along with a faster 7,200 rpm drive), I thought I’d experiment with this though. I mentioned to the Sumix support team that it would be highly useful to be able to record RAW sequence frames (to bring the data rate down to one third), and they said they would consider this possibility for a future upgrade. Until then, for me normal laptop operation would involve RAM-recording the Bayer video file. Is there any possibility for the user to change the still image format to Bayer? I’m always interested to hear about your extraordinary modifications –- any conclusions yet on the electronic anamorphic image quality?
John.

That is incredible, I thought there was always a save to bayer option. They should have included capture to disk with customisable interface (that allows control through the PC keyboard and any external controls connected to the PC) in the default package by now. It would be good to suggest this to them, as they have sold a number of cameras to video people that have not been useful because of the lack of these things.

Sumix avi files
 

Noah -- I made a few RAM recording tests on my desktop computer which usefully has 2 GB of RAM. I made an avi version of the smx file with SMXView, but this avi can not be imported into After Effects. The 16:9 frame size was 1280 x 720 at 25 fps. Is this a case of getting the Sumix codec into After Effects so that the Sumix avi will work? How would this be done? Obviously it is important to be able to import the avi footage into other software: any advice would be gratefully accepted. It's a shame Bayer tifs can't be recorded to RAM and converted to RGB (everything can read an RGB tif!).
Regards,
John.

Hmm I vaguely recall having some issue with the way sumix implements containging uncompressed RGB video in the AVI wrapper. I never went to far checking it out, but chances are you might be able to open the avi in virtualdub and just stream copy it into a new file maybe thatll fix whatever went wrong with it (maybe avi header is not done right or something). I guess i can test a few things out for you, see what the deal is with their avi sequences. I'll tell you if i find anything.

Thanks...
 

Many thanks Noah; greatly appreciated. I seem to remember a couple of years ago reading that Ben Syverson (who was then using a Sumix 150C camera) converted the Sumix Bayer file using his own software called linBayer, which was a 16-bit After Effects plug-in. Does anyone have a recent contact for Ben? Is linBayer still available anywhere?
John.

VirtualDub
 

Noah -- I tried VirtualDub and this played the Sumix avi! For your information (makes no sense to me of course!) the two VirtualDub warnings given for the clip were: "* AVI: index not found or damaged -- reconstructing via file scan. * AVI: invalid chunk detected at 2764810056. Enable aggressive recovery mode." From VirtualDub I was able to make an avi copy which imported into After Effects without problem, plays in Windows Media Player, etc. Thanks for the tip.

One of the things I wanted to do in After Effects was export a few particular tif frames to check image quality, and I was able to do this directly from VirtualDub as well -- bmp or tga (targa) files are the still image choices: I chose targa, and in Photoshop I was able to look at the frames as planned. Many thanks.
John.

John, you could also try reading through that Obin thread, these sorts of things were discussed there.

Wayne -- do you know what Ben Syverson is doing now? I was wondering about his linBayer plug-in. Google seems no good on it...
John.

Don't know, people come and go at a crazy rate. Look at his profile and send him message. If you can't send Chris a message and ask him to ask Ben to contact you.

Have you looked at that thread, he had a website with his software, there might be upto date contacts there. If it is no longer there, try google, and click on the cache option. If that is not there go to archive.org (thewayback engine) and search for the sites history there and see if you can get an email address. He's not to bad, he might like to look into this, he has a Sumix camera too, so he would probably be a good person to contact. Actually, I think, the last time I saw him, was on my technical thread.

If you are out of luck, drop a message in a thread he should still be subscribed to, or in other forums that he would still check.

Noah -- I'm writing up my initial experiences of the camera -- ok if I post it here, to keep the M73 stuff together (as Oscar is doing on Forrest's Elphel 333 thread) ? Since RAM recording to a laptop using the supplied camera application is different to your re-coded/self-build computer project, perhaps you'd prefer to keep this thread focused on that?
John.

You may post what you like, but it might be worthwhile to start your own thread since it might get confusing otherwise. But I certainly dont mind either way.
I probably wont be able to post too often since I now have a regular job and unfortunately dont have too much time to work on the camera (hopefully i will find time). When do have time I seem to end up getting distracted thinking about building cool mini custom computers to run the camera off of (which is obviously not a priority for the camera at the moment, since there is a lot of programming to be done), but I sort of need a new computer anyway. But now that I am done moving and settling into my new job/surroundings, I might be able to start messing with my M73 again.

Noah, any progress recently? I've recently started my project back up and I'm looking seriously at supporting the Sumix M72/M73 cameras, mainly because of the low cost compared to the SI cameras.

Have you been able to get anywhere near 48 fps? I'm hoping it might be possible to get 1280x720 @ 48 fps (8 or 10 bits) to cut down on the rolling shutter issues.

Also, do you know of any reasons to avoid the M72? For 1280x720 it looks like it might be a better choice. Just curious.