QHY5III Series USB3.0 Astronomy Camera User Manual V1.0

QHY5III Series USB3.0 Astronomy Camera User Manual V1.0
QHY5III Series USB3.0 Astronomy Camera User Manual V1.0
User Manual V1.0 Beta Version
Software Installation
1. Download and install the System Driver and ASCOM Driver from QHYCCD QHY5III Webpage
http://www.qhyccd.com/QHY5III.html
2. The QHY5III uses SharpCAP as the default capture software. Please download SharpCAP at
http://www.sharpcap.co.uk/sharpcap/downloads QHY5III can run under SharpCAP after V2.7 version
3. For more software support like the EZPlanetary, Native WDM driver and FireCapture. Please wait QHYCCD's news.
4. Connect QHY5III with USB3.0 cable. For first time the system will find new device and search the driver. You can skip the online
searching and computer will find the drivers. After installation you can find the device in the hardware manager. Please check if it is
similar like this:
Use QHY5III in SharpCAP
1.Connect camera
2.Run SharpCAP. If everything ok, the video image will appear automaticly and you will see a FPS number
3.If you run the sharpcap earlier than connect camera. You can use menu->cameras->rescan for cameras to search the camera and
check on the camera name (eg.QHY5III174).
4.To make sure the camera running the software will start the camera at lowest speed. So you may see the frame rate is much slower
than the highest frame rate that declared on QHY5III webpage. Now you can try to increase the performance. First you can try to set
the exposure time to 1ms. Then try to reduce the "USB Traffic" value. For modern computer like the i7-4core. It should get max
performance. But please note not all computer can get best performance. The CPU loading, the save-energy setting, the mainboard
performance and USB3.0 port performance may effect it. Sometimes the display performance will also effect it. So you can try to use
"zoom" function to redue the display size and see if it will help.
The QHY5III174 maxium frame rate at full resolution is about 138FPS. The QHY5III224 is 150FPS, QHY5IIII290 is 135FPS and the
QHY5III178 is 50FPS.
5. Adjust the offset. You may find the when block the light the image is not really zero. Sometimes this will cause the image contrast is
not so "good". You can adjust the offset to get a better background.You can open the histogram to confirm it.
if you are using the color camera, like QHY5III290C,QHY5III224C,QHY5III178C,QHY5III174C, It is very important to set the offset to a
low value and let the histogram peak is close to zero. Because the color camera color balance is multiple a ratio to the pixel value in
the FPGA. The bias will be multiple also and it may effect the color balance.
6. If you want to try the 16bit image. It is best to set the USB Traffic >=5(For QHY5III174). Otherwise the USB transfer may hang
because the data bandwidth is exceed the capability. Then switch the Colorspace to "mono16"
7.By check the "LX" mode you can expand the exposure setting range and do long exposure time. QHY5III series camera has the antiamp light control circuit and it can reduce the amplifer glow significantly, Escpecially for the IMX174,IMX224.
A typic long exposure image in +25C, 5sec exposure and 50% gain of QHY5III174M
Use QHY5III with ASCOM
You can connect many software which support ASCOM. Currently QHY5III only support normal ASCOM connection . Does not support
the ASCOM VIDEO connection.
MAXIMDL
1. Download and Install ascom platform from http://www.ascom-standards.org/
2. Make sure the QHY5III ASCOM driver is installed. If not please install it
3. Run MAXIMDL
4. In camera model select list, select ASCOM and then select QHYCCD-Cameras-Capture
5. In properties, select QHY5IIIxxx Camera
6. Normally, you can set the gain=1 and offset=10 to start. The speed and overscan calibration options are no using in QHY5III
camera.
This is a screen shot that QHY5III174M running in MAXIMDL. Since the QHY5III has no large on-camera frame buffer. In a small chance
you may meet the frame drop. In this condition, you need wait a longer time than the expected exposure time to get a frame.
When you change the exposure. CMOS sensor will generate one or more short exposure frame and you may receive this frame. And
the next frame will be a normal frame with correct exposure time.
Color Balance for Color QHY5III Camera
SharpCAP will start at the default RGB balance for color camera. Here is the screenshot of the QHY5III224C start up
For color camera. SharpCAP will show the WB Red/Green/Blue progress bar.
Since the color balace is the ratio between Red to Green and the Blue to Green. You can keep the Green color to 128 and adjust the
red and blue.
For example, in this image the blue is 255 and red is 161, green is 128. It looks the color is well white balanced. If you need more blue,
since it has reach to 255 and you can not get more. In this condition, you can reduce the green a little and you will have more room for
the ratio.
As we said before. If you are doing planetary imaging you should set the offset value as low as possible. To make the background
close to zero. Then you can easy to get correct color balance. Otherwise it will not easy to get it. The following image shows the offset
is good and you can not get good balance.
The reason is that the Color balance is a ratio of the RGB sensitvitity difference. So we use a ratio to multiple the RGB value and get it
done. But if there is a bias exist. The ratio will not corret. For example, the G sensitivity is two times than R.
G=2R In order to get white balance. We muliple a ratio of 2 to R
R'=2R= G so we get R=G
when a bias exist. The bias is a constant add to each pixel. So the image you see is:
R''=R+bias
G''=G+bias=2R+bias
Now the ratio R'':G''=(R+bias)/(2R+bias) and it is not equ to 1:2 . It shows the bias will effect the true value of the R:G. And the ratio of
R:G will vairous when the image light changed. It is hardly to correct with a fixed ratio.
But for DSO capture, You should keep the offset above zero and avoid the background is cut off. A background from 1000-5000 is a
good value(16bit mode) for DSO imaging.
PHD Guiding
You can use PHD Guiding software and the on-camera guide port of QHY5III Camera. PHDGuiding can connect with QHY5III camera
via ASCOM.
1.In PHDGudiing 2.5. Select ASCOM Camera Choose in Camera and On-camera in mount.
2.Select Connect and In ASCOM camera chooser , select QHYCCD-Camera-Capture
3.In QHYCCD Setup, Select QHY5IIIxxx camera
6. Normally, you can set the gain=1 and offset=10 to start. The speed and overscan calibration options are no using in QHY5III
camera.
7.Select "connect all"
8.Select
to connect the camera and mount
button to begin preview.
9. Select a star in the screen and click
to start calibration and guiding.
FAQs
1.Does QHY5III support 12bit or 14bit ?
QHY5III174,224,290 support 12bit output and QHY5III178 support 14bit output. All these output is convert to 16bit image to transfer
and save. (For 12bit, it is 0-2047 map to 0-65535, for 14bit it is 0-16383 map to 0-65535)
2.How to get maxium FPS
Since QHY5III is very high data bandwidth. Not all computer can get the maxium FPS. Normally I7-4core should no problem for that.
The CPU load will aslo effect the maxium FPS. So please reduce the CPU load by close other applications when using camera. If the
CPU load is too high, the software may become very slow or hangs.
3.How to avoid the camera hangs
If you camera always hangs. It may be caused by many reasons. You can check the following things.
3.1 If there is power leak for your mounts and computers? The power leak may cause the leak current transfer from computer to the
camera via the GND . This may effect the USB transfer and cause the data packet lost and cause it hang. You need make sure the
computer and the mount is well grounded.
3.2 If the USB port's voltage not enough? Some computer's USB port +5V is not enough. It may cause the camera always hangs. In
this condition you can use a powered USB3.0 HUB to connect camera and get the good +5V power for camera.
3.3 If your cpu load is too high? If CPU load is too high, it will cause many frame lost and cause the camera hangs. You can
increase the USB traffic value to reduce the FPS and get more stable video transfer.
3.4 If the USB cable connection is good enough? Sometimes the contact issue in the USB cable to camera or USB cable to
computer will cause the signal loss and cause camera always hangs. Espcially when you move the cables. In this condition. you can try
to add a little silicon oil into the USB socket/plug .This can increase the contact a lot better.
3.5 Avoid the statics. Sometimes the static electricity on human body will cause the camera hang. You can touch the computer metal
case for first before touch the camera to let the static elelctricity on your body release.
3.6 Some computer's front USB port is not so good for high speed transfer (The reason is it connected to mainboard by a cable and
which has no good signal integrity). If you found the camera always hangs on front USB port. You can try the USB port on backside of
the computer (which is connect to chipset directly on the mainboard).
4.What's the interface to telescope? How to use C/CS lens on QHY5III
Because QHY5III camera has 1.25inch eyepiece style design. So it can be intert into the 1.25inch eyepiece tube. No need extra
adapter.
QHY5III has the CS thread front part. It can connect with CS lens. The back focal length is 11mm to 11.5mm. Please note this value is
a little less than the 12.5mm standard CS back focal length. But you can use the 1.25inch spacer to get it to 12.5mm. The reason that
does not design to 12.5mm is to avoid the back focal length is longer than 12.5mm lens and you will no any other method to get the
infinine on the imager.
You need select the C or CS lens by the CMOS sensor size. Normally speaking the CS lens only covers 1/3inch sensor size. So
QHY5III178 and QHY5III174 can only use the C lens. QHY5III174 may need 1inch C lens. When using the C lens, the backfocal length
is 17.5mm, you need buy the C-CS entender to extend 5mm back focal length.
5.How to clean the CMOS sensor and the optic windows of the camera
If you found there is dust on the cmos sensor. You can screw off the front part of the QHY5III. The SONY CMOS sensor is clear glass
and it is no any coating, so that it is quite easy to clean it. You can use the tools that clean the DSLR or just a lens paper to clean it.
The optic window is the IR cut coating or AR coating. So you need to be careful when cleaning it. You can also use the DSLR clean
tools or the lens paper. Don't use big force to clean it. The coating is not so hard and it is easy to get scratch when you use big force
on it.
6. Does QHY5III working under FireCapture?
Yes. The lastest FireCapture supports QHY5III already. Please go to FireCapture website to download it.
QHY5III Mechanical Size
Front Side (Sensor)
Alberic's short exposure DSO capture introduction
Here is a little summary of my technique of short exposures imaging applied to Deep Sky Objects - DSOs. It's a mix between 'Lucky
Imaging' technique for planetary objects and long exposure for Deep Sky Objects.
Main advantages to use short exposures for DSO are :
- No need of auto-guiding system which may be difficult to calibrate,
- No need of super heavy, super expensive or super sturdy mounts,
- A 'planetary setup' is enough,
- Shorter exposures = less atmospheric disturbance effects on each frame. So a better resolution can be expected in good or even in
medium seeing conditions.
Main drawbacks :
- Few light compared to long exposure so the limit magnitude is lower than traditional long exposure mode. In fact the gap is not as
huge as we could expect if adding a lot of frames.
What are the limits of 'short exposure' ?
Good question...
For planetary target, limit is Neptune with an Infra-red filter, let's say 0.5 second in worst case. In most cases, less than 100 ms.
For DSOs, few objects (some bright planetary nebulas, open clusters or glubular clusters) could be imaged with 100 to 500 ms
exposition time with the most recent sensors.
For galaxies, lower limit exposure time will be 1 second to... 'more'. And 'more' is quickly limited by mount tracking, atmospheric
disturbances, wind and dark current of the camera when uncooled. For me a realistic value for 'more' is 5 seconds. So short exposure
for DSOs : between 100 ms to 5 sec. As you can see on my first post, for uncooled IMX 174 which have high dark current it's better to
decrease the upper limit to 3 seconds.
Frames acquisition :
First, align correctly your mount as done for long exposure.
I currently use a software for planetary/lunar/solar acquisition like SharpCap 2.8 and when it will be released, Firecapture.
Use only 16 bit Image format and save as TIFF or PNG.
Use high ain value : 60 - 90. Higher than 90% will give very noisy frames. Less than 60%, the readout noise will increase.
To reduce the noise pattern that may appear in background of final image, let the target move a little bit on the sensor. With the Hand
Pad, or if your mount has a bad Periodic Error curve, it will do the job.
Don't forget to make 'Dark' images after choosen target imaging session, as done for DSO with long exposure. The more frames, the
best.
I don't use Bias nor Flat with IMX174. For bigger size sensors I guess that Flat will be necessary.
Processing :
Before registration, I manually sort out the good images from the bad ones. I don't use automatic sort out. Of course it takes lot of time
but I'm sure it's efficient ! You can use automatic process if you prefer.
For registration, I use Registax 5.0 in monopoint mode ('Aligment Method' : 'Default'). An other solution is Autostakkert 2.6 which have
optimisation options to reduce horizontal noise pattern like IMX 174.
For post-processing I use Iris and Photoshop to adjust the curves and contrast.
Albéric
see more detail and the picture at
http://qhyccd.com/bbs/index.php?topic=5307.0
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