From: Alan Friedman <alan@greatarrow.com>
Date: March 29, 2009 8:22:39 PM MDT
To: Astro_IIDC@yahoogroups.com
Subject: Re: [Astro_IIDC] weekend solar images
Hi Ray,
An interesting question. In a perfect world (where the seeing is perfect all the time) I would say that the 41 series camera is definitely the way to go for lunar and solar imaging or wherever a larger field than 640x480 is important. But there are trade-offs. The 41 cameras are constrained to a max frame rate of 15fps and the smaller pixels account for a non-trivial reduction in sensitivity (also true for the 31 series cameras, though these can record at 30fps.) In average seeing (assuming you use MAP processing) you will find you need 4x the number of alignment points required for the smaller camera with its 1/4 of the FOV. Not much of an advantage here. For me the biggest plus is in being able to better see what I am doing as I compose the image in my head during capture. In those rare moments of good seeing I get very excited and tend to move around the lunar surface quickly trying to capture as much data as I can. With the bigger camera I can move more quickly and I tend to have less of those annoying mosaic voids from poorly planned camera pans. I have both the 41 series and 21 series cameras - if you can swing it, having both is the way to go IMO.
best regards,
Alan
On Mar 29, 2009, at 7:54 PM, Ray Byrne wrote:
Hi Alan,
I've noticed that you use your DMK41AF02 frequently for Solar and Lunar imaging and wonder whether I would benefit from purchasing one. I've got a bit of spare cash at the moment and I'm doing a general upgrade which includes an observatory so that I'll be more inclined to go out and do stuff anyway (which is the main thing). I'd be interested to know if I'd find Lunar and Solar imaging better using this larger format camera over my 21AF04
On 29 Mar 2009, at 23:21, Alan Friedman wrote:
Hi all,
I had a chance this weekend to capture some nice prominences on the edge of the sun:
http://www.avertedimagination.com/img_pages/tsunami_prom_20090328.html
sunny skies and best wishes,
Alan
Alan Friedman
ATB
Ray Byrne
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