NI 1772 camera exposure time adjustment resolution

What is the exposure time adjustment resolution capability for the NI 1772 camera? I'm getting only 10ms. Can I get 5 or even 1ms resolution?

Hi Rob,
I am unclear what the problem you are seeing is. Vision Builder AI does not appear to impose any restrictions on the granularity of the exposure time. You can put any value with precision down to sub-microsecond levels (no need to go by units of 10 microseconds).
As for the changes in intensity vs exposure time, keep in mind that image sensors and the hardware that reads them don't necessarilly behave linearly and so you may not see such a linear relationship in the data. While you said that you saw no change in intensity from 70us to 80us, were you looking at a single pixel or an average of the entire sensor? If you average it over the whole sensor I think you'll see the difference (although it might be small and less than a single count).
Eric

Similar Messages

ISight camera exposure time control for astrophotography

Does anyone know of a way, or an application that allows you to control the shutter speed/exposure time when taking a photo with an external iSight camera?
I am trying to adapt an external iSight camera for astro-photography. There are some excellent tutorials on how to remove the optics to expose the ccd, here. However for certain imaging you need long exposure shots like one could achieve with a DSLR. iGlasses is great for some control, but according to their customer support, does not allow control of the exposure time.
For other webcams there are suggested physical modifications including the use of a soldering iron! I am hoping that someone will be able to point me in the direction of a more elegant software solution! Most astronomy forum users recommend getting a netbook; I can't believe that this isn't something that a mac cannot do better!
Hope that some of you out there who know much more than I do can help out.
Many thanks,
Phil

Not for what you are trying to do.
I don't use anything like you seek, but http://www.outcastsoft.com/ASCASTROIIDC.html offers OS X software for compatible IIDC cameras (other than external iSight.) According to their site:
... Apple's FireWire iSight will never be supported as it lacks IIDC modes we need and is not capable of doing extended CCD exposure times. ...
If that is accurate, your Mac/OS X choices include acquiring:
(1) a supported IIDC camera,
(2) a UVC webcam that can work with something like
http://www.phoboslab.org/log/2009/07/uvc-camera-control-for-mac-os-x
(3) or a DSLR that offers Mac OS X compatible software for the features you need.
If none of those are acceptable within your needed timeframe, my only remaining suggestion would be to find software that does what you want and then buy whatever camera and computer is compatible with it.
Message was edited by: EZ Jim
Mac OSX 10.7.3

How to set the exposure time and the gain of a connected camera with IMAQ USB

A camera was connected to my computer with USB port and we can acquire the image through IMAQ USB. Now we have to set separately the exposure time and the gain with the camera's driver software provided by the manufacturer. My question is: how to set directly the exposure time and the gain of this camera in Labview?

Hi Frank
Welcome to the forum. Have fun
FranklinT wrote:
My question is: how to set directly the exposure time and the gain of this camera in Labview?
I think its not possible for USB Cameras.
Previous threads for your ref
http://forums.ni.com/t5/Machine-Vision/How-to-control-property-nodes-for-USB-camera/td-p/970306
http://forums.ni.com/t5/Machine-Vision/imaq-USB-property-page/td-p/926034
Sasi.
Certified LabVIEW Associate Developer
If you can DREAM it, You can DO it - Walt Disney

How do I create an ACR custom lens profile if camera exposure can't be set to manual?

How do I create an ACR custom lens profile if camera exposure can't be set to manual?
I ask this question for the Nokia 808 PureView 41MP camera. It produces stunning image quality but exposure can only be controlled via EV +/- compensation. I need a lens profile to correct for vignetting to get even skies in panorama (which turn out stunningly otherwise). There is no profile for the Nokia 808 PureView I am aware of and I'd like to produce one.
Is the Adobe profile creator able to correct for varying exposure using EXIF or overlapping parts of the chart or background?
Or would the Adobe profile creator ignore EXIF if I use studio flash to enforce a constant lightning situation, even if shutter speed would vary (aperture is constant and ISO can be set constant, just not the shutter speed)?
Or did Adobe produce a profile internally they can share?
Thanks.

If you read the first post, this is the camera-app of a 41MP Nokia Pureview 808 camera-phone, so maybe someone could write a new camera app but the phone is Symbian OS which is dead, making that unlikely.
http://www.digitaltrends.com/mobile/the-skeptics-guide-to-nokias-808-pureview-five-reasons -41-megapixels-are-not-a-gimmick/
http://www.digitaltrends.com/mobile/the-nokia-lumia-820-and-lumia-920-too-little-too-late/
It would probably be easier for Adobe to rewrite the LPC to allow vignetting to be computed from a single shot of a blank wall without a target in the shot, than to have someone rewrite a camera app that allows manual exposure.
Another idea about how to get the phone to keep a constant exposure would be to experiment with putting darker and lighter objects in the field-of-view away from the target area to make the camera metering adjust things so it’s exposure is the same from one shot to the next. This would take some doing but should work, unless the LPC uses the part of the frame that doesn’t contain the checkboard target in its computations.
You’re basically varying the scene around the target so the camera takes the same exposure of the target each time.

Which do you prefer: Increasing exposure or adjusting the tone curve?

I'd like to know how people here handle their images.
I use a Nikon D7100 in camera RAW. In camera my images are always in balance. In LR, if I select Auto Tone in Basics invariably it will adjust the exposure. I tend to adjust exposure near last in my workflow because I assume my camera had the exposure setting right. When I feel I need to adjust the exposure my first stop is the Tone Curve. I'm wondering a couple of things:
1) I know we edit by the specifics of each photo, but generally do you make adjustments to Exposure or the Tone Curve first?
2) Is there a reason or a time to prefer one over the other?
Thanks,

My recommendation:
(note: I am interpreting "exposure", in your question, to mean "dynamic range at right wall of histogram", i.e. white point)
Adjust basics exposure first (before tone/point curve), but note: you may not be able to go all the way using the exposure slider. Next stop (if necessary): +whites, but note: it may not be optimal to go all the way using whites. Final stop (if necessary): cinch in the the exposure by dragging white point to the left via the point curve.
Rationale: basics have some intelligence and magic that tone curve does not. If you do tone curve first, you've missed some opportunities..
Still a begging question: how much exposure vs. whites vs. tone curve (point curve).
Note: go easy on the contrast at first, and assure blacks are sufficiently seated using blacks slider (and maybe tone/point curve).
Likewise, cranking whites up will increase global contrast, so if you take a shot at blacks and whites before contrast, then you may avoid a common mistake: radically wrong contrast due to adjusting before establishing ballpark black & white slider values.
Anyway, be aware that increased PV2012 exposure (and/or whites) is designed to be used with -highlights (note: there is no "brightness" slider), and to avoid making things too washed out (or over-jamming the highlights) it may be desirable to substitute +whites and/or +shadows for some +exposure.
Note: tones may gang up (on the right side of the histogram) in a non-optimal way when using +exposure and/or +whites, in which case it may be better to use point curve for white point adjustment (e.g. leftward drag). For example, sometimes the whites will be overly compressed if you don't bring white point in on the curve instead.
Rules of thumb:
Most of my normal photos end up with:
+exposure (to fully brighten)
+whites (for full dynamic range without excessive exposure setting)
-highlights (for dialing back +exposure and/or +whites)
+shadows (so -blacks and doesn't leave image with overly dark shadows)
-blacks (for full dynamic range without needing as much contrast)
*contrast: depends - if overly contrasty to begin with (or a lot of -blacks and/or +whites are employed), this usually gets dialed back; if underly contrasty to begin with (or +blacks and/or -whites have been employed), this usually gets bumped up.
(for abnormal photos or when desiring abnormal results - anything goes..).
Other common mistakes (in addition to wrong contrast and/or non-optimal balance between exposure & whites..):
trying to recover highlights via -whites. try -highlights (and maybe +whites) before -whites.
Warning signs:
if you have very high values for +shadows and -highlights, you may have contrast set too high.
if you have a positive value for highlights, you may have contrast/exposure/whites too low.
if you have a negative value for shadows, you may have contrast too low, or blacks/exposure too high.
Miscellaneous:
Try +clarity and +saturation (and/or +vibrance) to pump it up, if reduced contrast and/or increased exposure has left it looking a little washed out.. (likewise, -saturation if +contrast has left it looking a little too "rich"..).
You already know this, but for the sake of completeness (and other readers): you can learn by clicking 'Auto Tone' "button". You may need to dial back the exposure afterward etc. but it can be very educational none-the-less..
Of course, you can always fine-tune tone using tone curve (e.g. if image is just way overbright, like some snow shots, try tugging the midpoint downward..).
Don't forget the locals for final spot toning.
In case you haven't gleaned yet, adjusting via PV2012 is not the same as you might think at first - you don't just set exposure/black/white points and leave them, and then adjust everything else. e.g. -highlights pulls white point down more than -whites does (but +whites brings white point back up, which means you usually need to adjust in tandem..), so be prepared for a lot of back n' forth, to lessen with experience..
PS - There are tutorial videos galore, but at the risk of opposing Adobe and their sycophants, be forewarned: some are geared to how they wished PV2012 was (simple), and not to how it really is (interdependent image-dependent settings..) - examples:
top-down is touted, but that ignores black/white point issues which can lead to radically wrong contrast (and/or exposure) setting.
often, adjustment of blacks is considered optional/fine-tuning, but blacks sometimes need large value adjustment, and dramatically impacts contrast & shadow brightness..
often, adjustment of whites is considered optional/fine-tuning, but sometimes optimal toning can only be had by using a large whites value adjustment, which dramatically impacts contrast, and exposure..
cteavin wrote:
I tend to adjust exposure near last in my workflow because I assume my camera had the exposure setting right.
In case not clear yet, adjusting exposure and/or whites (and/or white point on curve) and all the rest is often done to turn an image "with potential" into a very nice image, not just to compensate for in-camera exposure imperfection. I have lots of under-exposed images that end with -exposure (granted, usually +whites), and vice-versas.. That said, if you don't know whether to crank it up or down, there is something to be said for passing until you do..
Lastly, for emphasis: exposure slider is an intelligent slider. It behaves more like normal exposure adjusters at lower values, and more like brightness adjusters at higher values (has clipping protection and highlight roll-off logic which kicks in as you crank it up..). So, it's a mistake to think of adjusting it just to make up for non-optimal camera exposure setting.
Sorry for verbose answer, but there is really no short answer which doesn't run the risk of being bad advice: best way to adjust "exposure" depends...
Cheers,
Rob

[P70] Camera exposure? & camera some settings can't be "saved"

First about camera exposure ,sometime when OPAN camera app auto mode)
(it about 5 second)
camera
some settings when close the camera and turn back them can't be saved
Special adjustable options , very affectt when using.
In last, the P70 camera hard to “ZOOM” , can't use volume button .
and the
When I have kept the brightness at the dimmest level and enter the Stock Lenovo Gallery , Vidoes application the brightness increases by itself to the max (I Suppose) until I leave the application and comes back to where I had set it.(This does not happen with the Google Photos app)
@https://forums.lenovo.com/t5/A-and-P-Series/P70-A-Problems/td-p/2033962

My Qosmio is an F10-124. It was running a fully updated version of XP MCE and had not been much trouble apart from a completely new motherboard etc under warranty! It also has 2gig memory and a 160gig HDD which for some reason now is only showing 127gig.
I purchased an upgrade WIN7 package a few weeks ago and installed it, and it runs fine, better I think than XP. Drivers took a while to update but it was plain sailing really.
However I had a niggling feeling that there might be a better BIOS by now. Toshiba's site told me the latest version for this machine is 1.40 whereas it already has version 2.0. I think the site just has no support for these re-boarded machines which have R at the end of the part number. This trips up Tempro until the R is removed. I have tried the only W7 32 BIOS I can find so far, version 2.20, but installation fails, so maybe it's best left alone for now.
Don't know if this is any more than academic but at least I have succeeded running W7. Now, Qosmio Player, that's another story.

Best practice when camera exposure must be changed between each grab?

Hi all,
I'm acquiring two images in fairly quick succession from a GigE camera. In an initialization state I use 'Open' then 'Configure Grab'. Then, in my acquire state I read in the exposure required via a property node and use a 'Grab'. Then I loop around and do a second 'Grab'. The first image has a long exposure, the second image needs a shorter exposure.
Mostly this works well but occasionally my second image is too bright (meaning the exposure is too long.) Is this a problem with how I'm acquiring the image? (Is 'Grab' the best vi to use?) Or, do I need to give the camera more time to make the change? (Add in a delay?)
All thoughts must appreciated.

The problem is that you never really know when your new exposure is received and when it is applied.
Moreover when you call the grab, you do not really acquire an image (the acquisition process in your case seems to be continuous), you just read an image in the computer memory.
So your Grab/change exposure time/grab sequence does not include the "real" acquisition process (exposing the camera sensor to generate an image).
There are many possibilities, most of them require triggering. For most of them I would recommend the use the "low level" Vis instead the "Configure Grab/Grab" ones :
1- For every image, stop acquisition, set exposure then start acquisition and get the image.
2- One technique you could try, is to use software trigger to control the image acquisition process :
    - configure the camera to trigger mode and Software trigger as the trigger source
    - for each image :
           - set the exposure time,
           - if needed, add a short delay
           - use a property node to generate a sw trigger
           - read the image.
3- Most of cameras include a pulse width trigger mode : the width of the exposure pulse defines the exposure time for the image. So, if you're able to generate a pulse train with alternate pulse widths (long pulse for the first image, short pulse for the second one), it is probably the most efficient way as you can use the camera at maximum frame rate if your trigger pulse train is well defined.
4- Some cameras have special features dedicated to the task you want to implement : for instance if you use a Sony camera, you may check if it includes a feature called bulk mode.
Photonfocus cameras have a powerful I/O controller that you can use to create sophisticated tasks. However, this will probably require a good understanding if the hardware and maybe some tricky programming.
Hope this helps,
Sami
Sami Fathallah
ALLIANCE VISION
HW and SW Components for Scientific Imaging and Machine Vision
http://www.alliancevision.com

Applying time adjustment twice.

I guess the time adjustment works on what is showing, not on the original photo time. I used Batch Change twice on some photos because some of them weren't imported with the time adjustment, so I thought, what the heck I'm just telling it the camera time (always UTC) and the local time zone, so if I do it again it shouldn't matter (I'm assuming Aperture is looking at the original photo time capture). But Aperture does the shift twice. I see this as a bug, but maybe my thinking is wrong.
This happens frequently for me because I use two camera's and also my girl friends pictures, and when I'm importing I sometimes forget to set the time adjustment.
Update:
I dug into the library and the original photo has not been change and "Date Time Original" and "Date Time Digitized" are still the correct UTC zone. (But we all knew that since Aperture never changes the original.) Why can't I use this as the basis for resetting the "Image Date"?
Message was edited by: MtnBiker

user12860499 wrote:
Hi all,
A developer came to me saying that he put a 11gr2 table into default compression mode which was already in default compresssion mode.After that 32GB of table got compressed to 26GB. How is this possible?Is it that it is double compressed?
Right now I do not have access to that database nor do I know how to find what happed there. Only thing I can think of is that , the table was originally put in compression in 11gr1 and then again applied compression in 11gr2,so some algorithm enhancement might have done this.
Any thoughs?
with this I am also wondering what happens when enahancements are introduced in any feature I mean let say in case of compression if a algorithm enhanced will the enahancement be applied on the whole table or the data that will be inserted/updated post such upgrade?multiple compression option available in 11gR2 with different compression level.
see complete detail
http://docs.oracle.com/cd/E11882_01/server.112/e25494/tables002.htm#ADMIN11630
and Compression can occur while data is being inserted, updated, or bulk loaded into a table.

Setting exposure time in C

I am using C to setting exposure time for my Camera Link CCD,exposure time should be 12 microsecond.
I know there is a function imgSetCameraAttributeNumeric()/imgSetCameraAttributeString(),but which constant refers to exposure time?
How to set?Plz give me an example.
Thank u very much!

phrakture wrote:
Side note, if you're using C99 (you should!), you can include <stdbool> and use bool/true/false.
Side note #2. There is no way, in C, to get the size of an array. You need to use a "trick" to know your size. Typically, when using code like you have, one does:
#include <stdbool>
typedef struct
char sprite;
bool walkable;
} FIELD;
const static FIELD field_table[] =
{' ', true},
{'#', false},
{0, false}
And then you loop until my_field.sprite == 0. Alternatively, you could add a "#define FIELD_TABLE_LENGTH 2" or something, but that adds potential errors if you were to add an entry at a later date and forget to change then length.
stdbool is a nice hack where you have
#define true 1
#define false 0
as for the size of an array, since it's known at compile time, sizeof will do
size_t s = sizeof(field_table) / sizeof(FIELD);
and since we're targeting C99, then proper initialisation of structs looks like this:
FIELD a = {.sprite = '#', .walkable = true };

Time adjustment problem!!

I accidently entered the wrong information while importing some photos and got the wrong time zone, I then tried to do a batch adjustment to get the correct time and just made matters worse. I am totally confused on how to get the correct adjusted time zone. Can anyone lead me in the right direction on how to either restore the default camera time so that I can then do a batch change to the zone I need or explain to me how I can get the correct zone entered manually.
Thanks

I agree, Apertures way seems a little counter intuitive but I think they did it that way to account for the time zones being named within Apertures file, not just the time it was shot without any relationship to time zones. That being said what you need to do is make sure the second lines time zone is your actual time zone, then on the first pick out a time zone the correct number of hours in front of or behind you to correct the time difference in the files. \
So if you need to shift the time period an hour later, put in a time zone that is 1 hour behind yours in the "Camera's Time Zone" and put your time zone in the "Actual Time Zone".
Do the opposite for going 1 hour earlier, pick a time zone 1 hour before yours and use yours for the actual time zone.

Exposure time with externally triggered MC1362 and PCIe-1433

Hi,
I am capturing images using a Mikrotron EoSens CL MC1362 camera and NI PCIe-1433 frame grabber. I have a question about exposure time - which I'm not sure if it is related to the frame grabber, the camera, or the combination, but hopefully someone here can help.
I'm running an external signal to the SMB connector on the frame grabber, and have the camera set to operate in "Pulse width mode", which allows the frame grabber to take control.
My question is:
How do I determine the exposure time from the parameters of the external signal? It's a square wave, and the duty cycle seems to control the exposure time.
I would guess that the exposure time, E= (D/f), where f is the signal frequency and D is the duty cycle? e.g. for f=1kHz and D=80%, the exposure time would be E=0.8ms. Is that correct?
The camera manual can be found here:
http://g4.com.tw/web/file/product/usermanual/995-EoSens%203CL-MC1361-Manual.pdf
and I have included a screenshot of the revelant portions which seem to describe how pulse width works. In particular it says "Exposure time is defined by the width of the external signal". Is that equivalent to my E=D/f idea?
Thanks in advance for any help.

Great, thank you!
"The exposure stays on while the pulse is high." - I basically just wanted to double check this, because it doesn't really say that explicitly in the manual and I find their wording confusing and didn't understand what the three traces in the diagram are.
Thanks again,
Stu

Control exposure time and gain with FPGA as frame grabber

Hi,
I'm using a Basler acA2000 340kc camera with a PCIe1473R FPGA as frame grabber.
I managed to obtain images succesfully by modifying some of the sample codes. I can also control some of the camera settings thorugh the Pylon software.
Nevertheless, I'd like to control the exposure time and gain in LabView.
Any idea on how to do this?
Thanks

Ultimate the serial port on the board is controlled by the code on the FPGA. There are shipping examples that provide the FPGA-side implementation of interfacing the serial port to a host-side interface, which then bridges it to a TCP port, which is bridged to a DLL called "clsernif.dll", which interfaces through the common "clallserial.dll" that Pylon can use to access the camera.
Depending on your needs, you could interface at any of these layers.
-If you need to do this with the ultimate in determinism, you could have the FPGA issue these serial commands directly as needed
-If can do it from the host CPU, you could modify the host-side code and send/receive serial traffic to the FPGA code directly
-You could examine the example code that bridges to a TCP port and simple write some host VIs that talk directly to it by opening a TCP session to the socket it uses.
Eric

How to set long exposure times on a Powershot sd800?

Is there a way to set long exposure times on a Powershot SD800 camera? Am I limited to what the preset menus offer?

zoltanszucs,
You can try shooting in the Long Shutter Mode. Please follow these steps:
With the camera in Manual mode, you will need to go into the menu and enable Long Shutter.
Exit the menu and press the FUNC button.
Select the Exposure Compensation setting and press the MENU button.
Use the LEFT and RIGHT buttons to select the shutter speed.
If this is a time sensitive-matter, additional support options are available at Contact Us.
Did this answer your question? Please click the Accept as Solution button so that others may find the answer as well.

Why do I get lots of noise in my photos on the D30 at long exposure times with 100 ISO speed? Help!

So I'm using a Canon D30 (3.1 megapixel). My ISO speed is set to 100, but when take phots at very slow shutter speeds I get a lot of noise. And I mean a lot. Can anybody help?

Long exposure time is the 2nd main way to get noise in an image. Not a lot you can do other than post processing. How long an exposure? Perhaps a compromise like ISO 200 and a shutter that is half as long (twice as fast) would be slightly better if you played around with it. Or perhaps that would be even worse.
Scott
Canon 6D, Canon T3i, EF 70-200mm L f/2.8 IS mk2; EF 24-105 f/4 L; EF-S 17-55mm f/2.8 IS; EF 85mm f/1.8; Sigma 35mm f/1.4 "Art"; EF 1.4x extender mk. 3; 3x Phottix Mitros+ speedlites
Why do so many people say "fer-tographer"? Do they take "fertographs"?

I created an album from photos taken off three different cameras. I am sorting the photos manually and when I close iPhoto, the photos move back either by date or by camera import time. How can I keep the photos from moving around?

I created an album from photos taken off three different cameras. I am sorting the photos manually and when I close iPhoto, the photos move back either by date or by camera import time. How can I keep the photos from moving around?

Don't tell us, tell them
http://www.apple.com/feedback/macosx.html is the place for feature requests and feedback

NI 1772 camera exposure time adjustment resolution

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