Telescope Reviews: Re: Gassendi and environs 16 May 2008

... Thanks (again) for most enjoyable moments that this forum can possibly give!

What a detailed pile of facts to study from - and as Larry said, these kind of analysis really gets the pics into breathing!

Mardi - regarding those minor changes in the light conditions on mountain peaks on photos.

Time and again I've been surprised by just looking at Registax processing the single frames from an avi (as these pics are recorded for instant @ 25 fps). There can be quite major shiftments on the mountain peaks especially - that is on the way that light from them has dwelled onto the CCD / CMOS chip - actually varying according to seeing (for instance boiling conditions can cause these).

The only way to be quite on the safe side with these minor changes on photoes would be to process enough frames from avi or just use a decent single shot.

And - of course - a drawing would settle the problem as one could have a visual confirmation tool to assist the memory or as a reference.

Sometimes it is also amazing how some minor peaks can be left in darkness unless one postprocesses the pic in a way that the contrast and brightness become more revealing.

It is just amazing how much detail can be lurking in a pic - as the version that the camera gives is just its own interpretation of the brightness, contrast and saturation.

Plenty of details can many times be digged up due to postprocessing (for instance via unsharp mask which enhances the contrast between single pixels).

- And folks, please, do not take this kind of talk like criticism - or merely discussing technicalities on an observation oriented thrad!

It just happens to be so, that modern digital photos are quite far from what the eye is able to see. At their best, they can deliver to a most enjoyable degree quite revealing details - even small details - when the processing enables those quantum reflections from the lightdwells of the charged couple device (CCD) to come into daylight. - Or should one say Moonlight

And regarding that idea of posting accurate time for the observation (or shot) - that is a fact I learned from Jim - and I'm very happy for his advice on that (among many other things).

One should also be aware that modern digital cameras also record on a pic or avi a thing called metadata. There is also the correct time of shooting there, if only the camera was first told the correct time.

Thus in a digital pic this kind of stamping can be found among the actual bitflow having the photographic data. This is also used to determine whether a pic has been tempered with (for instance if it is used as evidence or something) as every processing leaves a mark on the metadata section.

- So, actually no need for even wristwatches (if that feels like a bother to look at the time) in this, if one just puts the camera to correct date and time.

Be well all!

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Share - and you shall have it all

Timo Keski-Petäjä

CtheMoon

Observation shelter KuuMaja (MoonHut)

TAL 250K*Celestron C8-N*SkyWatcher Skymax 150 Pro*TAL1(Mizar)*EQ6 Pro SynScan*Celestron Advanced GT (CG-5 GOTO)*Baader Hyperion Clickstop Zoom 8-24*17 mm UWA-70*TeleVue BIG 2x Barlow*Celestron 2x Barlow Ultima SV Series

Edited by Mare Nectaris (05/18/08 01:47 PM)

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