Leica Biosystems CW4000 DC Cameras with IA Applications - Manual (Page 5)

Leica DC Camera, with IA applications 3 Installation advice Issue 2
Feb 2002
For use with IA apps, switch off the auto gamma and auto contrast in the DC Twain. Do a Reset of these values. If
you leave these auto functions on, the intensity of the image can vary, this is OK for image documentation but can
be a problem when you want to use a fixed detection threshold.
For use with IA apps do not use Auto Exposure for repeated image grabbing. (This function is in the Image Server
dialog - so it can be used to quickly get an image, however once you know the settings to use, Auto Exposure is
not recommended as it slows down the acquisition rate).
For best colour rendition set the gamma to a value of 1 and only make small changes to gamma. You will find that
small changes to gamma can have a large effect on the image quality.
Note: with the DC300F and DC350F there is a non-linearity in the exposure time at around 114.5ms (due
to the physical properties of the camera) it is best to adjust the light level so that you are faster or
slower than this.
To display live images with fastest refresh rate you should have an acquire time of less than 114 msec.
Be aware that the resolution of the images displayed in live mode (for DC300 & DC500) is lower than the final
acquired image. For example you may see pixelation and aliasing. This is reasonable so that you have a fast
image refresh.
When you use a DC500 + Leica QFluoro with narrow band filters, the exposure can appear good on the screen live
image, but when you grab an image it is darker than expected (for red and blue filters, not green). At the moment
there is no explanation for this. However when you switch the camera to 16 bit mode you can use the Auto-
scaling function to get high brightness images and this works well.
In Leica MW when using interactive measurements, switch off 'fit to window', this speeds up the image refresh.
Limitations Limitations Limitations Limitations
Note: There are some image resolutions that do not acquire good images and these issues will be
resolved in a later release. These are DC500 3900 x 3090 9 shot and DC300 with the expanded resolution
image. For the DC500 using 2600 x 2060 16 shot, please switch graphic display to 24 bit colour
DC cameras cannot be used with Autofocus functions of the Peripheral Server as used by QWin and MW.
Some of the Leica MW processing functions (e.g. QGrain) are limited to 2k x 2k images due to the speed of
processing of large images.
The resolution of the image selection with DC500 does not display correctly with DC Twain version 4.1.1.
In general for IA applications, you will find that images of 1280 x 1100 or smaller give good performance and you
can see the whole image on a monitor set to a suitably high resolution.
These IA applications are for Windows 2000 only
only only only with at least 256MB ram installed in the PC. For use with images
greater than 2k x 2k, 512MB ram should be installed (or 768 MB ram with Qfluoro).