Interstellarum Publishes Astronomy Cameras Advert
The German language astronomy newsletter by Daniel Fischer, published by the magazine Interstellarum (Oculum-Verlag) has just released its latest edition. The bi-monthly publication contains current news and information for the amateur astronomy community.
We are delighted to announce that the first German language advert for The Imaging Source astronomy cameras was included in the latest edition. The following banner was published in the middle of the newsletter, as the only advertiser:
Translated, the advert reads:
The Next Generation of Astronomy Cameras. Learn more »
Our German speaking friends can read the full text of the newsletter, by clicking on the following screenshot:
Francesco Megli said,
March 4, 2008 @ 16:18
I would like to gain more information about the performance of DMK CCD-camera as compared to the StellaCam EX I from AVA. Please understand my point: I was so excited about StellaCam at first, but afterwards I began to be deluded by and by, and by now I know it is no miracle, just one of the many similar devices, with a normal pro and con balance. I do not need to repeat this experience again with Imaging Source!
The heart of CCD-cameras is the CCD sensor. StellaCam EX I mounts a Sony ICX428AL, while DMKAU04.AS has a Sony ICX098BL sensor. I have found specifications in the Sony website http://www.sony.net/Products/SC-HP/pro/image_senser/index.html
but apart from the notation that “EXview HAD CCD is a trademark of Sony Corporation. EXview HAD CCD is a CCD that drastically improves light efficiency by including near infrared light region as a basic structure of HAD (Hole-Accumulation Diode) sensor” attached to the ICX428AL, I was not able to understand the technical information for correctly compare the two sensors. Would you please be so kind to do it for me and tell me your conclusions?
Second point. Admitting that I will be willing to buy a DMK camera, which one of the following is the best choice:
DMK 21AU04.AS (B/W) with colour filter set & wheel
DFK 21AU04.AS ?
In fact, I know that the monochrome sensor has a higher resolution as compared to the colour one, since the latter has to accommodate three colour channels in the same pixel number as the monochrome, so that each colour will use one-third of the whole pixels array. At the end, with the monochrome sensor plus colour filters one should get three colour AVI films each one collected with the full pixel array totalizing a 9-fold resolution with respect to the colour sensor. Am I right?
Third point. What about the need of a frame grabber? Does the …AU… (USB version) eliminate it? Does this mean that the …AU… versions are of the “plug and play” kind?
Fourth point. Does aquisition frequency 60 fps means 60 frames per second? To build one frame two fields are required, odd and even. Since the two fields are interlaced, they do not add information to the final frame. In order to add more information to the final frame at 60 fps, the real aquisition frequency should be 120 field per second: two fields total one frame and in this case acquisition frequency would really be 60 frames per second. In case the declared 60 fps means 60 fields per second, so the result should be declared to be 30 frames per second!
The issue is of great concern in case of mediocre seeing. Depending upon the seeing-related displacement speed of the image, if the image is displaced in less than one-thirtieth of a second, than the image will be loaded also on adjacent pixels, resulting to be smeared on more pixels than due. In other words, a real 60 fps (120 fields per second) acquisition rate will beat a seeing with less than 60 Hz image displacement frequency. Stella Cam EX I has 25 frames per second acquisition frequency, unable to beat mediocre seeing. If DMK’s declared figure of 60 fps “f” corresponds to frames, so that is ok (meaning 120 fields), but if it corresponds to fields, then there is no advantage.
I would like to hear comments from you on this before delivering an order.
Thank you.
Best regards
Francesco M. Megli