Stub Mandrel

Oh poo :-(

It seem it is only 320 x240 :-(

58 minutes ago, RuralBill said:

Yep that's it, follow that guide and you will be fine....

That's the route I have followed, but wcrsmac says my camera isn't supported.

Anotehr update the camera is a PCVC 820K/20,

If I change the numbers to match the hardware ID of my camera (rather than the one given for an 840K in the example), it tries to load, but fails as it says the files security hash no longer matches the one in the catalogue :-(

I guess W7 didn't do this security check, but W8 does.

Thanks,

Its not a PRO one, it's a PCVC 820K/20, I have found the same instructions in English on Cloudy Nights.

If I change the numbers to match the hardware ID of my camera (rather than the one given in the example), it tries to load, but fails as it says the files security hash no longer matches the one in the catalogue :-(

I guess W7 didn't do this security check, but W8 does.

OIK, I've got it all running - the old Lappy has both XP and 2K on it, so i worked under XP.I used Phillip's on capture program and WcRmac as described on the threads.

wcrmac says it is a toucam XS and that it is not supported by it.

BUT the camera installs itself as a Toucam II 820K

Oh woe!

I found this on cloudy nights, I will try it:

http://www.cloudynights.com/topic/275496-getting-a-toucam-pro-840k-to-work-with-windows-7/

Will a Windows 2K machine do - I have one in a drawer?

Hi folks,

Will this work for a TOUCAM II? I have just received a brand new unopened box one, ready for me to dismember for LX mod and peltier cooling...!

Result - or so I thought, today a brand new never unboxed Toucam that cost me 12 Euros arrived from Spain.

I am getting very confused trying to find W8 drivers for it, can anyone point me at a SIMPLE solution?

Did you use any flats? They might get rid of the smudges.

7 minutes ago, Rich_B said:

Having just joined a few days ago I have been overwhelmed by the helpful responses to my posts. I have already ordered my first scope and accessories and saved a lot of time and money by following the advice provided by the members here. 

At this moment in time I cannot think of any way to improve the site.

10/10 

Another innocent victim of the astro-virus!

It amazes me how some parts of the sky are overflowing with stars like that shot, and others are almost empty - at least until you use a Hubble to spot the zillions of galaxies hidden in the background.

Long ago the editor of Practical Electronics apologise for the spelling 'flourescent' in an article. He said something like "we've downgraded our typist, because graded brains make finer fluor."

16 minutes ago, DRT said:

Are you doubting my legendary willpower, Stu?

LOL! I think it's your telescope buying power that is the stuff of legend

Sorry Will, I was punting for a free sample ;-)

Happy to review one of these for you ;-)

Is that dog really looking through the finderscope?  ;-)

2 hours ago, Pig said:

Here are mine :-)

 

 

 

 

 

They appear to have been newtralised.

This situation is almost exactly analogous to that for Chinese-made machine tools. At first sight identical machines from the same factory, but each importer's version made to s different spec that can be slightly or wildly different in the detail, and differences in QC as well, not to mention the differences in spares stock and after sales support between good retailers and those who 'operate out of a container at the docks'.

Rotate 90-degrees clockwise to make it match the upright 'camera view'.

Looking down on my small scope tracking the transit. Note the 'advanced solar hood focusing aid' lying on the grass...

1 hour ago, The Admiral said:

Having looked at Samir's article, it set we pondering, and this is my take on what goes on!

When we image, the light photons liberate electronic charge in each of the pixels of the sensor; the more photons, the more charge liberated. At the end of the exposure, the charge in each pixel is measured in an analogue way, but for the purposes of producing a digital RAW file it has to be converted into a digital signal. This is the job of the analogue-to-digital converter, or ADC. At 'base' or 'native' ISO, this is a straight conversion of the analogue signal. In order to give a range of sensitivities, as measured on an increasing ISO scale, the analogue signal is amplified before being passed to the ADC, so that weaker signals have a greater amplitude before measurement. There is a downside to this, however, because at some point the ADC will saturate, and this means that pixels which have received a high number of photons, and therefore contain a large liberated charge, will be above the measurement abilities of the ADC. The net affect of this is that the  dynamic range is reduced, more so as the ISO values are increased.

There is a further complication, because manufacturers introduce digital gain as well as analogue gain, at higher ISOs, and are often very guarded about the processes that they use, so it isn't always obvious what the native ISO of the sensor is and at what point they introduce digital gain. We don't want to operate in the digital gain region.

I managed to find this information for my camera from http://www.photonstophotos.net/Charts/RN_ADU.htm

Read noise increases linearly with ISO but above ISO1600 it is clear that the operation of the sensor moves into a different regime. Curves for other cameras can be quite different, according to the strategies adopted by the camera manufacturers.

So what about the histogram? The histogram is a graphical display of the distribution of light intensity recorded by the sensor. It is not taken directly from the sensor, but rather from a jpeg processed from the RAW data. In producing the jpeg, a colour calibration curve and a response curve is applied in order to make the linear data recorded by the sensor appear more as the eye would perceive the scene. These curves are specific to camera models. Typically, the x-coordinate of the histogram would be linearly scaled from 0 to 256, so that no signal would be zero, and the maximum signal before saturation, or clipping, occurs would be 256. Some cameras show the histograms for each RGB colour, but others just a combined luminance curve. Because the histogram is taken from the jpeg, it should be clear that the display will vary according to the ISO setting, so that a source giving a single peak near the bottom end would have a peak which shifts progressively to the right as the ISO setting used to image that source is raised. Therefore, any recommendation to use, say 10% or 30%, for the placing of the sky-fog peak seems to me to be somewhat erroneous. I guess the main thing is to ensure that there is a gap between the peak and the zero of the histogram, but not one so wide that the rest of the curve is squashed to the right.

Up until now I've not taken a lot of notice of the histogram, but I've now gone through all my images just to find out what I've been getting. The following are typical:

This is M64, at 1600ISO, single frame of 30s

 

and this is M42, at 1600ISO, single frame of 15s.

Notice that in both of these one can make out a small component of the curve at the far right hand end of the histogram, and although this isn't the case for all my images, it is so in by far the majority of cases. So even with an exposure of 15s, I am still at risk of saturating the brightest stars. What I am not sure of though, is whether this really means that the sensor is saturated as well, but if it is, then it is likely that colour information will be lost for these particular objects. With this particular image, I guess I had the option of dropping the ISO to try to recapture some of the dynamic range, perhaps to as low as 400ISO, as there is plenty of room to the left of the sky-fog peak. That is predicated on being able to see the distribution well enough on the camera itself of course, as the histograms presented here are taken from my RAW processor. I could reduce the exposure time, but that implies a reduction in the number of photons captured. That is unacceptable as I want to maximise the signal-to-noise ratio to get the cleanest possible image.

Here endeth the lesson

Ian

A very good post, but my thought is that the area on far right is occupied by bright stars in MOST images is tiny but we can explore it. Choosing an image of a light-polluted sky (over Walsall's light dome)

Corel Photo Paint has an option to adjust histogram clipping. Its auto setting allows 5% clipping  and the histogram of a rather light polluted sky looks like this, kjsut as it would in Photoshop or on the back of the camera:

Now look at this histogram with 100% clipping allowed:

In particular note the 'secondary peak' at far right, that's the bright star Arcturus and other brighter stars. The interesting thing is that it doesn't appear to be significantly clipped...

A shame Photoshop doesn't have this great feature of Photo-paint.

Those sort of tables need Danish Oil every year. Forget one year and they've had it... I know!

Another one salvaged from the grot. Luckily there was a rectangle virtually without dust. Stacking in AS!2 and Registax then combining both roughly 50/50 seems to have eliminated all the noise.

The signal from the CCD/CMOS has to be processed to perform the A2D conversion. ISO affects the gain applied during that conversion and as it can't be zero gain then EVERY digital image has to have some effective ISO rating

I've read that with my Canon D450 and long exposures the lowest read noise is at 800 iso, and taht iso 1600 isn't significantly worse. Try it and see.