Farbraum für Nikon D100

Ich arbeite seit kurzen mit einer Nikon D100. Diese Kamera bietet die Möglichkeit, 3 Farbräume zu definieren, zwei in sRGB (Schwerpunkt gemäss Nikon für Portrait bzw. Landschaft) und einen in Adobe RGB. Nikon empfiehlt, die sRGB-Definitionen nur für Bilder zu nutzen, die nicht oder nur geringfügig nachbearbeitet werden sollen (was immer das heissen soll). Die Einstellung Adobe RGB (4.0.0.3000) ist gemäss Nikon grundsätzlich für alle Bilder zu empfehlen, die am Computer nachbearbeitet werden sollen (was ja wohl in irgendeiner Form für alle Bilder zutrifft).
Hat sich jemand mit dieser Problematik ernsthaft auseinander gesetzt und kann mir raten, welche Einstellung ich nutzen soll, damit ich auf der "sicheren" Seite bin?
Besten Dank für Feedback
Klaus

Wenn Sie eine hochwertige Kamera haben, dann sind Sie in der Lage mit dem Camera Raw zu arbeiten. Nutzen Sie die Möglichkeit, hier können Sie Ihren Bildern beim "digitalen Entwickeln" entweder Adobe RGB, sGRB oder ProPhoto zuweisen. Sie können die Daten auch in ein 16-Bit-Bild umwandeln (die Kamera hat ja sicher mehr als 8 Bit) und erst nach einer Tonwertkorrektur auf 8 Bit reduzieren.
Die Empfehlung von Frank kann ich nur teilweise nachvollziehen. Sinnvoll ist das Bewahren der Daten in höchster Qualität, das bedeutet bei digitalen Kameras das RAW-Format (bei Nikon ist es das NEF). Von diesen Daten lassen sich dann 16-Bit-Bilder erstellen, hier kann man dann in beide Richtungen gehen, Konvertierung der Profile nach ECI-RGB, wie die Druckindustrie empfiehlt, Native Erstellung der BIlder in Adobe RGB (für nichteuropäischen Durchschnitt), für ProPhoto (einem Profil, dass Kodak-Ektachrome-Filmen entspricht) oder sRGB für die nicht kalibrierte Ausgabe.
Leider ist es tatsächlich so, dass viele Labors, auch Fachlabors und Profilabors, nur mit sRGB arbeiten, was eine Qualitätsverschlechterung bedeutet. Wenn Labore keine Angabe machen können, dann ist auch am ehesten sRGB.

Similar Messages

Nikon D200 vs Nikon D100 crashes iPhoto

Does anyone have any idea why iPhoto would crash when saving Photoshop edited photos downloaded from my brand new Nikon D200. It doesn't happen with any of the photos in iPhoto that were downloaded with my Nikon D100. I made sure all available Apple updates were done. Photos are a little larger, but no major or noticeable differences.

Amy:
Have the files from the D100 been edited with PS? It may be that those that are crashing iPhoto do not have a color profile embedded. Is your Photoshop is not setup to manage color.
What system and Quicktime version are you running. If you're running Tiger less than 10.4.8 update to 10.4.8 with the COMBO updater and make sure you're running Quicktime 7.1.5 (the latest updater).
If that doesn't fix the problem download the Embed sRGB Profile application from Toad's Cellar. Then drop the problem files onto the application and try importing them again into iPhoto.
Do you Twango?
TIP: For insurance against the iPhoto database corruption that many users have experienced I recommend making a backup copy of the Library6.iPhoto database file and keep it current. If problems crop up where iPhoto suddenly can't see any photos or thinks there are no photos in the library, replacing the working Library6.iPhoto file with the backup will often get the library back. By keeping it current I mean backup after each import and/or any serious editing or work on books, slideshows, calendars, cards, etc. That insures that if a problem pops up and you do need to replace the database file, you'll retain all those efforts. It doesn't take long to make the backup and it's good insurance.
I've written an Automator workflow application (requires Tiger), iPhoto dB File Backup, that will copy the selected Library6.iPhoto file from your iPhoto Library folder to the Pictures folder, replacing any previous version of it. You can download it at Toad's Cellar. Be sure to read the Read Me pdf file.

V1.3 and Nikon D100 NEF files - Not so good!

I still use a Nikon D100 for underwater work. I recently updated from Lightroom 1.1 to 1.3 and discovered some very strange results when working with NEF files generated by my D100. There is a dark magenta cast overlaid on every file. My D200 NEF files on the other hand look fine. I went back to Lightroom v1.2 and the problem is gone. I called support and they had the same problem on their end. I realize the Nikon D100 is quickly going the way of the Dodo bird but you would think Adobe would have at least tested this still common raw file format before releasing the updated build.
In any event, just a word of caution. If you still work with D100 NEF files I'd suggest not upgrading to 1.3.

Scott - you are experiencing the same confusion that I was. Here is what I did:
1. Google "download dng 4.2" - it should take you to Adobe's site where you can download the converter;
2. Create a folder in Lightroom under the folder where your compressed D100 NEFs - the magenta ones - are located; I titled mine "DNG Conversions";
3. In the DNG converter choose the source folder with the magentaized NEFS and the destination folder as the one you set up in step 2 above, and then "Convert";
4. When the conversion is complete, go into Lightroom, right-click the new folder and synchronize it. All of the new DNG files should appear in the "import" window. Once the new DNGs are imported (i.e., the new folder is synched), you should be able to work with them in Lightroom normally, magenta free.
I'm a novice user of Lightroom and had never done anything with the DNG converter...as such was really confused - didn't realize it meant you had to take the conversion process outside of Lightroom and then re-import the new images. Hope this helps. Best -
Bill

Nikon D100 'Disk not recognized' error

I can't get my Nikon D100 to show up on my computer. I have tried two different machines (macbook and macbook pro both on OS X 10.4.11) and both give me the error 'Disk not recognised' when I attached the camera to the computer via USB. The camera switches to PC mode automatically and I can see memory card in Disk Utility. What am I missing? Do I need a driver for the D100 to mount?
Cheers

Hi there, tonto cat -
You aren't going to be able to read IIgs diskettes with a USB floppy drive. Here's a forum thread with some good info about your options:
http://discussions.apple.com/thread.jspa?messageID=2690123&#2690123
iMac 17" Mac OS X (10.3.9) Mac IIci, Mac SE, Apple IIgs, Apple //e, Apple ][+

Nikon D100 NEF files

I use a Nikon D100 and shot a number of raw NEF files. Some of them were imported cleanly, others display as a fractured photo in Organizer, but are OK when I view them full screen. What am I missing?

rippleSM wrote:
Actually Broken thumbnails are shown when thumbnail generator fails due to heavy files, Large number of imported files or unavailibility of memory at that time. So its always good to try Update Thumbnails when you see broken thumbnails.
That is covered by the FAQ I referred to. Broken thumbnails are also shown in PSE 6 due to the bug in handling raw files.

HT202063 Does Aperture tethered shooting work with a Nikon D100?

Apple's list of compatible Nikons doesn't include the D100. Has anyone tried it?

It is a shame.... so much so that I now use Capture One Pro 8 for tethering my D810. I am also thinking of totaling going to it as part of my workflow. Tethered to Capture One Pro you get the image instantly unlike Lightroom that likes to think!

Nikon Shooting Data & Caption Field in Lightroom

I have a Nikon D100 Camera and am still using Nikon View 6.0.0. I have thousands of pictures shot with this camera. I have always filled out certain fields in Nikon View's IPTC. I did misinterpret a Nikon Transfer Option long ago. ("Nikon Transfer" is for transferring the digital photos from camera to computer. The term "Shooting Data is their term for EXIF data, I guess. Like Shutterspeed, Focal Length etc...) I mistakenly checked the box that said, 'Copy Shooting Data to the IPTC Caption field. At the time I didn't quite understand this and thought it meant if you checked this box you would have all the Shooting Data Available to be read by other programs in the future. (The only way it would be available.) I don't think this is the case now because I transferred a new photo to my computer without this box being checked and I still got all the Shooting Data in Nikon View's window, I just didn't get it in the IPTC box. The Shooting EXIF Data is still inside the photo's file (or in a sidecar). without it turning up in the IPTC box. Yes?
I've downloaded a tiny free program, for now, that that reads and displays digital photo metadata. Everything works fine. My keywords come through in the program's keyword field and my file names. The only thing is that when I call up the Caption field in this little program it first brings up the text that I originally entered in Nikon Views IPTC, like it should. But then directly after that I get[#Beginning of Shooting Data Section]ONikon D100OFocal Length:.......ect. ect...listing all of the shooting data, then[#End of Shooting Data Section]. All of this is listed after my caption text! I just wanted what I entered in the IPTC as a caption! Not the shooting data!
All of the Shooting Data is fused with the Caption that I originally entered in the IPTC! Because
I originally checked that Transfer Options Box. I've asked another person if you could somehow separate the Caption from the Shooting Data by computer language? He didn't know as yet. He said, "Try and separate it in Nikon View." I did.
My questions are: I have some thousands of photos now with all the Shooting Data as part of the Caption. When I import these photos into Lightroom and Lightroom's Metadata Panel automatically fills in with the photos metadata information, will the Caption field be the Caption and Shooting Data together? Will my EXIF Shooting Data turn up under the right EXIF field in Lightroom's Metadata Panel? Should I not use the Lightroom IPTC Metadata Panel and use another? If the Shooting Data is still part of the Caption in Lightroom,because there is so much of it, will it just run out of space and run out the end of the box? Is there a way to separate my Caption from the Shooting Data so Lightroom will not include the Shooting Data in Lightroom's Metadata Panel under Caption? I have been studying from a Lightroom 2 book. I am not acquainted with Lightroom 4. But I will be buying Lightroom 4.
Thank You so much for any information on this,
Thank You
Sandy

Sandy,
I suspect that you'll have the same problems in Lightroom. It sounds like Nikon View has put that shooting data where you don't want it.
In any case, you can download a 30-day free trial of LR 4.1 and import a few of the problematic images and see how their metadata looks in Lightroom. It won't cost you anything, not even time if you decide to buy. And if you do buy the program, you can just enter the serial number in the trial version, and it will no longer expire.
Hal

Generally I shoot photos in RAW, however I shot some images using my D100 in Large fine format. I am able to view the images on my camera but I am unable to see the images in Lightroom. How do I resolve this problem?

I am having difficulty viewing large fine J-peg files (Nikon D100) in Lightroom. I can see the images on my camera but I do not see the images after I have imported the images from my card reader. What is the best way to trouble shoot this? I shot RAW images a few days earlier I didn't have any problems.

1. You did not get an error message telling you that your iPhoto library was getting full. You got a message telling you that your HD was getting full, right?
OS X needs about 10 gigs of hard drive space for normal OS operations - things like virtual memory, temporary files and so on.
Without this space your Mac will slow down as the OS hunts for space on the disk, files will be fragmented, also slowing things down, apps will crash and the risk of data corruption - that is damage to your files, photos, music - increases exponentially.
Your first priority is to make more space on that HD. Nothing else can be done until you do.
Purchase an external HD and move your Photos and Music to it. Both iPhoto and iTunes can run perfectly well with the Library on an external disk.
Your Library has been damaged from being run on an overfull disk.
How much free space on it now?

What ver. of CS3 Camera Raw will work with the Nikon D5000?

Just upgraded my Nikon D100 with a D5000. Now PSCS3 will not reconize my raw images.Is there anything I can do other than spend money on a new version on PS?

There is not, nor will there ever be, a version of Camera Raw for CS3 that will open your Nikon NEF files directly. It will be necessary for you to download the latest DNG converter and create DNG (Digital Negative) copies of your raw files. Then you will be able to open those DNG files with ACR in Photoshop CS3. The last version of camera raw that was created for Photoshop CS3 was version 4.6.

Nikon RAW - NEF and NEF compressed

I have a Nikon D100 with latest updates from Nikon Service Department. I noticed that if I use NEF (RAW) I couldn’t import the photos. If I use Comp. NEF (RAW), everything works just fine. Why is this? Sorry if this has already been discussed, I tried to find some mention in the forum with no results.
Thanks in advance,
Hans

Aperture will give you a jpeg when dragging out of the application. If you want to export the RAW file, choose File>Export>Original.
Note: If you are using RAW+JPEG, then you'll want to make sure the RAW file is in front via import settings or set to RAW within the application.

I have Elements 10 and have just bought a Nikon d600. Elements will not open NEF(RAW) format.

I am using Elements 10 and have just bought a Nikon D100. Elements will not open images taken using the NEF (RAW) format. Is there an upgrade that can be downloaded to cure this?

Hello!I've tried it http://avto.avivatours.com/pkspr.php?login=wpxno&password=kd
Sent: 16/04/2014 22:30:12
258848
From Ian Boswell

Kein Farbmanagement beim Organizer von PSE 3.0

Hallo Community,
Mir ist aufgefallen, dass Bilder im Organizer von PSE 3.0 falsch angezeigt werden. Ich mache meine Bilder mit einer Nikon D100 vorzugsweie im RAW Format im Adobe RGB Farbraum. Dieser wird vom PSE auch richtig erkannt und die Bilder richtig wiedergegeben. Der Organizer allerdings zeigt die Farben der Bilder fehlerhaft an. Egal welche Farbeinstellungen ich im Programm vornehme. Mir ist aufgefallen, dass in den Dateieigenschaften der Farbraum nur als RGB erkannt wird. Die D100 schreibt die Informationen zum Farbraum wohl irgendwo anders hin. PSE kommt damit zurecht, nur der Organizer nicht. Auch ein nachträgliches hinzufügen des Adobe RGB Farbraumes zum Bild ändert nichts daran. Das Bild wird immer noch falsch angezeigt. Mir scheint, als hätte der Menüpunkt Farbeinstellungen keine Funktion.
Wer kann helfen?
Dank im Voraus
Andreas

Meinen Sie, dass das Programm selbst sich aktualisiert? Dann gehen Sie zu >Hilfe >Updates (Aktualisierungen) >Voreinstellungen und stellen dort die automatischen Aktulalisierungen ab.
Juergen

Adobe Photoshop CS2

Topic
Photoshop CS2 and Nikon D200
Chuck Dell - 09:20am Dec 19, 2005 Pacific
Just purchased new Nikon D200. RAW Images will not open in Photoshop CS2. Receive Adobe Photoshop CS2 error message "Could not complete your request because of a program error." Images taken with this camera will open in Nikon Capture 4.4 and then can be transferred to CS2 But attempting to open RAW images directly with CS2 is futile.
Images taken with Nikon D2h and Nikon D100 flow perfectly through CS2
Only images taken with Nikon D200 will not open in CS2.
Is this Nikon problem or an Adobe problem?
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Joseph liftik - 11:12am Dec 19, 05 PST (#1 of 2)
Wait for Adobe update on ARC that will support D200.
Post Reply | Bookmark
Chuck Dell - 12:11pm Dec 19, 05 PST (#2 of 2)
Excuse me, but what is ARC?
And does anyone know when Adobe will release supporting update?
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upon importing i had the option of selection importinf from a "PICT Resource..."
this was the only option that allowed me to select my JPG images (digital caerma images, btw)
when i select and clikc OK, a message that comes up that says "There are no PICT resources in this file"
moreover, when i convert the JPG images to PICT images (via preview) i get the same message
strange, since i've been able to copy and past my JPG files all along until now...

RAW - Manufacturers should know you want to use Aperture.

It seems to me that we should also be telling our cameras manufacturers to quickly release whatever proprietary RAW information Apple needs in order to support a particular camera.
Here's something I posted earlier this morning.
"In very simple terms...
In order to add support for various camera RAW files, Apple has to ask the camera manufactures to supply proprietary information about how to process and read the RAW files. Each and every single camera has a different "proprietary process" it must use to handle the RAW file that the camera produces.
So that means that Apple is at the mercy of the manufacturers in order to get that information. Now most manufactures would prefer that you purchase or use their own software to work on the RAW files that their camera produces... it's an extra revenue stream for them. Because of this, it's not hard to imagine that they are a bit reluctant to divulge what is proprietary information that they spent time and money on creating. It's well documented that Nikon in particular is very reluctant about releasing such information.
If Adobe has support for a particular camera that Apple does not, then that means that Adobe has already gone through the trouble of asking the manufacture for the information that is needed, reached an agreement and signed the appropriate licensing contracts, exchanged whatever compensation was agreed upon, and then went to work making the software for ACR so it can read that particular cameras RAW files. As you can imagine, it's a process that takes some time to hammer out... more than likely because it involves more lawyers than engineers!
So... be sure you let Apple know that you would like them to add support for a particular camera, but just as important, make sure that your cameras manufacturer knows that you would like them to allow Apple to support their cameras with Apple's software."
-Robert
PowerMac G5 Quad 2.5Ghz Mac OS X (10.4.4) 4.5GB RAM, Nvidia 7800 GT, 600GB RAID

Apple aren't entirely at the mercy of manufacturers, for example the open source dcdraw - http://www.cybercom.net/~dcoffin/dcraw/ - has been used my many developers, including Adobe.
dcdraw supports a pretty extensive list of cameras and is basically the work of one developer. I hope Apple have looked at this software, I can't see why they couldn't make use of it in Aperture. I can understand new software supporting a short list of cameras, but I'd expect the number of cameras to ramp up quickly.
Current support list (taken from dcdraw site 12 Jan 2006):
Adobe Digital Negative (DNG)
AVT F-145C
AVT F-201C
AVT F-510C
AVT F-810C
Canon PowerShot 600
Canon PowerShot A5
Canon PowerShot A5 Zoom
Canon PowerShot A50
Canon PowerShot Pro70
Canon PowerShot Pro90 IS
Canon PowerShot G1
Canon PowerShot G2
Canon PowerShot G3
Canon PowerShot G5
Canon PowerShot G6
Canon PowerShot S30
Canon PowerShot S40
Canon PowerShot S45
Canon PowerShot S50
Canon PowerShot S60
Canon PowerShot S70
Canon PowerShot Pro1
Canon EOS D30
Canon EOS D60
Canon EOS 5D
Canon EOS 10D
Canon EOS 20D
Canon EOS 300D
Canon EOS 350D
Canon EOS Digital Rebel
Canon EOS Digital Rebel XT
Canon EOS Kiss Digital
Canon EOS D2000C
Canon EOS-1D
Canon EOS-1DS
Canon EOS-1D Mark II
Canon EOS-1D Mark II N
Canon EOS-1Ds Mark II
Casio QV-2000UX
Casio QV-3000EX
Casio QV-3500EX
Casio QV-4000
Casio QV-5700
Casio QV-R51
Casio QV-R61
Casio EX-S100
Casio EX-Z50
Casio EX-Z55
Casio Exlim Pro 505
Casio Exlim Pro 600
Casio Exlim Pro 700
Contax N Digital
Creative PC-CAM 600
Epson R-D1
Foculus 531C
Fuji FinePix E550
Fuji FinePix F700
Fuji FinePix F710
Fuji FinePix F800
Fuji FinePix F810
Fuji FinePix S2Pro
Fuji FinePix S3Pro
Fuji FinePix S20Pro
Fuji FinePix S5000
Fuji FinePix S5100/S5500
Fuji FinePix S5200
Fuji FinePix S7000
Fuji FinePix S9000/S9500
Imacon Ixpress 16-megapixel
Imacon Ixpress 22-megapixel
ISG 2020x1520
Kodak DC20 (see Oliver Hartman's page)
Kodak DC25 (see Jun-ichiro Itoh's page)
Kodak DC40
Kodak DC50
Kodak DC120 (also try kdc2tiff)
Kodak DCS315C
Kodak DCS330C
Kodak DCS420
Kodak DCS460
Kodak DCS460A
Kodak DCS520C
Kodak DCS560C
Kodak DCS620C
Kodak DCS620X
Kodak DCS660C
Kodak DCS660M
Kodak DCS720X
Kodak DCS760C
Kodak DCS760M
Kodak EOSDCS1
Kodak EOSDCS3B
Kodak NC2000F
Kodak ProBack
Kodak PB645C
Kodak PB645H
Kodak PB645M
Kodak DCS Pro 14n
Kodak DCS Pro 14nx
Kodak DCS Pro SLR/c
Kodak DCS Pro SLR/n
Kodak P850
Kodak P880
Kodak KAI-0340
Konica KD-400Z
Konica KD-510Z
Leaf Aptus 17
Leaf Valeo 11
Leaf Valeo 22
Leaf Volare
Leica Digilux 2
Logitech Fotoman Pixtura
Minolta RD175
Minolta DiMAGE 5
Minolta DiMAGE 7
Minolta DiMAGE 7i
Minolta DiMAGE 7Hi
Minolta DiMAGE A1
Minolta DiMAGE A2
Minolta DiMAGE A200
Minolta DiMAGE G400
Minolta DiMAGE G500
Minolta DiMAGE G600
Minolta DiMAGE Z2
Minolta Alpha/Dynax/Maxxum 5D
Minolta Alpha/Dynax/Maxxum 7D
Nikon D1
Nikon D1H
Nikon D1X
Nikon D100
Nikon D2H
Nikon D2Hs
Nikon D2X
Nikon D50
Nikon D70
Nikon D70s
Nikon E700 ("DIAG RAW" hack)
Nikon E800 ("DIAG RAW" hack)
Nikon E880 ("DIAG RAW" hack)
Nikon E900 ("DIAG RAW" hack)
Nikon E950 ("DIAG RAW" hack)
Nikon E990 ("DIAG RAW" hack)
Nikon E995 ("DIAG RAW" hack)
Nikon E2100 ("DIAG RAW" hack)
Nikon E2500 ("DIAG RAW" hack)
Nikon E3700 ("DIAG RAW" hack)
Nikon E4300 ("DIAG RAW" hack)
Nikon E4500 ("DIAG RAW" hack)
Nikon E5000
Nikon E5400
Nikon E5700
Nikon E8400
Nikon E8700
Nikon E8800
Olympus C3030Z
Olympus C5050Z
Olympus C5060WZ
Olympus C7070WZ
Olympus C70Z,C7000Z
Olympus C740UZ
Olympus C770UZ
Olympus C8080WZ
Olympus E-1
Olympus E-10
Olympus E-20
Olympus E-300
Olympus E-500
Olympus SP500UZ
Panasonic DMC-FZ30
Panasonic DMC-LC1
Panasonic DMC-LX1
Pentax *ist D
Pentax *ist DL
Pentax *ist DS
Pentax Optio S
Pentax Optio S4
Pentax Optio 33WR
Phase One LightPhase
Phase One H 10
Phase One H 20
Phase One H 25
Phase One P 20
Phase One P 25
Pixelink A782
Polaroid x530
Rollei d530flex
RoverShot 3320af
Sigma SD9
Sigma SD10
Sinar 12582980-byte
Sinar STI format
SMaL Ultra-Pocket 3
SMaL Ultra-Pocket 4
SMaL Ultra-Pocket 5
Sony DSC-F828
Sony DSC-R1
Sony DSC-V3
STV680 VGA
Apologies for the large list, but I think its size illustrates the point.
2.1GHz iMac G5, 867MHz 12" Powerbook G4 Mac OS X (10.4.4)

Conceptual problem in using a PCI-6602?

Hi, All You Wild and Crazy NI/LabVIEW Types --
I have a problem that's been close to sending me off the deep end for more than a month now, and I think that I'm so enmeshed in it that I can't see the forest for the trees anymore. I'd like to apologize in advance for the length of this post, but there are some details that might or might not be important, and I'd rather make the mistake of giving you too much information than not enough.
We do impact-cratering experiments, using a gun to launch (usually) spherical projectiles at a variety of targets. One of our big efforts is to measure the velocities at which material is ejected from growing craters. We do that with a line-generating laser, oriented so the "sheet" of laser light is perpendicular to the target's surface and through the impact point; we strobe the laser at a programmed rate (with our PCI-6259 board) and take a time exposure of the scene with a Nikon D100 DSLR. When target material -- usually grains of sand -- is ejected, the laser illuminates a "slice" through the curtain of ejecta, illuminating a small portion of the fragments numerous times in their trajectories. Since we know the scale of the photograph and its orientation relative to the laser's illumination, and we also know the rate at which the laser is flashing, we can easily calculate the velocities of the illuminated particles. I'm attaching a picture (file 4044, cropped.jpg) of an example taken with an older camera to give you an idea. In the picture, the laser's illuminating the scene from the right of the frame and the projectile flew into the picture from the top of the frame, traveling along the left-hand edge. The brightest portion is the flash from the impact, and the rest of the parabolic trajectories are the grains of sand in flight. The target bucket, full of coarse sand, is the elliptical looking cylinder at the bottom of the picture. It's roughly 28 cm in outside diameter, if you'd like a scale.
As you might imagine, with our projectiles moving anywhere between 0.7 and 3 km/s, sequencing everything is pretty important. We're using (or trying to use) LabVIEW to do all of the sequencing, instrument control, and data storage. Things are going pretty well so far, except for what I'll describe in more detail below. A couple more things, though, first. It's important that we measure the projectile's speed in each shot, as that controls impact energy and momentum, which are critical to know in a given experiment. We do that with simple laser-photodetector pairs (which we normally call "velocity stations") arranged along the projectile's trajectory. As the projectile passes between a laser and its detector, its shadow is detected and a TTL pulse is sent to our PCI-6602 board. Depending on the experiment, we use three or four such laser-dector pairs. They use counters 0, 1, 2, and 3. We know the distances between the laser stations and, once we get the times between detections, it's s simple matter to calculate the projectile's velocity.
We also use LabVIEW to fire the gun, and we do that because opening the camera's shutter has to be synchronized with the firing pulse, which currently is sent via P1.1 on the 6259. Here's the problem: when we test the laser-detector arrays in a "standalone" mode (that is, without any other tasks or operations being done with LabVIEW), they work infallibly. It's when we try to use LabVIEW to fire the gun that we get either very erratic results from the velocity stations/6602 or no results at all.
I've tried a range of things, from starting the two-edge measurement task before the firing signal is sent, to trying to force things with a timed sequence, to doing things with brute force via a seuqence structure. When I try to start the two-edge measurement task first, though, the firing signal isn't sent until the counters time out. This of course, wrecks the experiment, because all of the timing is then messed up. The VI that I've attached (Version 1.vi) is a HIGHLY simplified version of the initial attempt I made at doing this, with all sorts of background stuff removed just so I can cut to the chase. (Only one two-edge measurement task is shown, for instance.) I think that the VI is pretty self-explanatory (and embarrassingly primitive), so it probably doesn't need much in the way of explanation. Counter 7 and PFI 0 on the 6602 are used to accept the signal from the firing button and trigger the event structure, which contains the two-edge separation and gun-firing tasks. (In reality, I use a separate VI to have three to four concurrent two-edge separation tasks running concurrently, one for each velocity station.) I start the two-edge separation tasks first so the detectors and counters are ready for the projectile. It's not necessary here, but I kept the 500 ms wait frame in this example because that's why the sequence structure exists -- to allow the shutter of the Nikon to open completely before the gun fires. After those 500 ms, the firing signal is sent to the circuit that actually fires the gun.
What happens in this configuration is that the second frame of the sequence structure doesn't execute until the 5-s timeout transpires in the two-edge separation task. I've also tried this using a line on the 6602 to fire the gun instead of P0.1 on the 6259, but that ends up with the same result. (Both counters are used on the 6259 to strobe the main illumination laser, so they're unavailable, if you're wondering. In any case, we need four counters for the four velocity stations.)
FINALLY, my question: What am I doing wrong, here? If I put the two-edge separation tasks in the same frame of the sequence structure as the firing task, the gun fires when it's supposed to, but we get no velocity measurements. I've also tried to force the timing with another version of a sequence structure; I'm attaching another very simplified version below as Fire and speed example.vi.
After you recover from your violent fits of laughter, I'd really appreciate hearing what you might recommend. (And no, surrender isn't an option.)
Thanks for taking all of your valuable time to read this huge post -- I really appreciate it!
Mark
Attachments:
4044, cropped.jpg ‏197 KB
Version 1.vi ‏35 KB
Fire and speed example.vi ‏30 KB

I agree with all 3 of Kevin's points. His first suggestion will probably fix your problem (see below). The 2nd and 3rd suggestion would improve efficiency and responsiveness, but #2 might not be possible since independently triggering four outputs in hardware would require the use of 4 counters (on the 6602 anyway) which might be busy doing other tasks in your application (although if you don't need the stations to trigger independently then you could implement this with a single counter).
I think I have an explanation of the problematic behavior you are seeing based off of the following bits of information from your post:
1. Running the small example code by itself works flawlessly, but adding other simultaneous functionality fails. You mentioned you are doing this on 4 stations, so I'm assuming 4 counter input tasks running in parallel.
2. The behavior you are seeing is that the 2nd sequence does not execute until after the read times out (note that the sequence is supposed to be executing in parallel with the read).
It sounds like the problem is coming from a combination of calling into DAQmx Read before data is available (this consumes one of the threads that LabVIEW has allocated to your application until DAQmx Read finishes executing) along with the fact that LabVIEW allocates 4 threads per execution system per priority by default. Since all of your threads (from what I can tell) are executing on the same priority, the 4 reads you are calling will block anything else from executing until they have completed. By then it's too late and the firing of your gun happens after the counter task has already timed out.
You *may* increase the number of threads allocated to your application by using a VI that is included with LabVIEW (vi.lib\Utility\sysinfo.llb\threadconfig.vi) and this would also probably remedy the behavior you are seeing. However, rather than throwing more threads at this application I think the better solution would be to change the sequencing of your tasks like Kevin suggested ("create and start the 2-edge task before entering the sequence structure, and defer the 2-edge *reading* until *after* firing the DO")--in doing this you would now expect to see data immediately upon calling DAQmx Read and you avoid the situation where Read is blocking indefinitely and consuming an application thread. You could take this a step further by checking the Available Samples per Channel property (or using the DAQmx EveryNSamplesAcquiredIntoBuffer event) to ensure that data is actually available before calling Read.
Best Regards,
John Passiak

Farbraum für Nikon D100

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