Internal Memory Buffer

luling_skies

With the 16 megabit cameras the image files are very large and strain the USB connections to download in a timely manner. This is especially true if the computer has USB 2.0 connection or if a USB hub or active extension cable is used. Employing an internal buffer in the camera will help avoid image loss. At least one of your competitors offers this feature in their APS-C chip cameras.

Tim

Sam@ZWO

Hi Tim

all ASI Cameras have internal memory buffer

just the buffer is not big enough to store one image

but no image will lose as the image buffer can store some lines of one image

and sensor will wait these lines transferred and start one new transfer later

so there is Handshake protocol to keep data safe

the advantage have a larger buffer is you can read out one image into buffer in very fast speed to avoid amp-glow issue, that's why 071 has amp-glow when connect USB2.0 and nearly no amp-glow when connect USB3.0

anyway we will add such feature in our future products

luling_skies

Thank you Sam. I'm buying a new computer with USB 3 ports and a faster CPU. I found that my CPU is running a full speed when capturing and saving camera images while stacking images in AstroToaster. Hopefully the new laptop will resolve this issue.

Tim

bwallis

I really second this suggestion .... I have been fighting the Amp Glow issue on an ASI 1600MM-c for a month and finally got a USB 3.0 laptop which did solve the issue.... but it was quite an effort to try to solve the Amp Glow mess before it was clear that the only solution was to try out a USB 3.0 system

Having an on camera memory capable of grabbing and image that could instantly download an image which could then be transferred via USB 2.0 or 3.0 with ZERO Amp Glow would be a major upgrade

Brad Wallis

Sam@ZWO

bwallis wrote:
I really second this suggestion .... I have been fighting the Amp Glow issue on an ASI 1600MM-c for a month and finally got a USB 3.0 laptop which did solve the issue.... but it was quite an effort to try to solve the Amp Glow mess before it was clear that the only solution was to try out a USB 3.0 system

Having an on camera memory capable of grabbing and image that could instantly download an image which could then be transferred via USB 2.0 or 3.0 with ZERO Amp Glow would be a major upgrade

Brad Wallis

thanks Brad, we are working on it!

bwallis

I will tell you that even with the USB 3.0 system I still see the Amp Glow.... I'm not shooting the bright objects.... I'm working super faint stuff and Narrow Band imaging..... The Amp Glow still shows up after applying Darks.... it is just not as painfully obvious..... so... doing an instantaneous in camera image transfer to a chip is going to be the only way to end the Amp Glow problem..... I love the 1600..... I just wish the Amp Glow was gone !!!! Brad Wallis

bwallis

So... I found some information that says the internal memory for super fast downloads may well NOT cure the Amp Glow issue..... I thought the Amp Glow occurred during download of the date from the chip.... so I thought the super fast image transfer would cure the problem.... If that is not the case then is there any cure in sight for the Amp GLow issue ???

Sam@ZWO

the amp-glow come from 2 parts, slow download speed cause it and the sensor itself cause it too

but usually you can calibrate it well under the same setting

bwallis

I am having a really hard time calibrating it out..... using darks taken at identical settings....

when shooting really faint objects I nearly always find some residual noise from the Amp Glow.... to me that says there must be some variability in the Amp Glow..... if it was not varying by some small amount it should really calibrate out of the images with no problem ...... or am I missing somethng ???

Sam@ZWO

did you use the predefined setting in our ASCOM?