Sensor Analysis and then Optimal Settings... Is that reall all there is to it?

[eseavey]

I ran the sensor analysis carefully and plan to use the results for future imaging sessions. For my QHY224C camera I though I'd use the "Optimize for Dynamic Rage" and " Noise less than 1%"option next time I image. Is that really all there is to it to get the best exposures for a given imaging period? Is it recommended to increase/decrease exposure times for fainter/brighter objects as I see fit?

Thanks

[admin]

If you have used the 'brain' to calculate the exposure and gain for 1% noise contribution then making the exposures longer will not gain you anything (even for faint targets). Well... not very much anyway - by setting a 1% threshold then you can only improve the noise in the image by a further 1% even if you make the exposure 10x or 100x or 1000x as long as the recommendation, so not worth going longer.

You *may* want to go for shorter exposures under some circumstances:

* If the sub frames are over exposed - stars too blown out for instance - then just reduce the exposure
* If the sub frame time is too long for your guiding/tracking then re-run the brain and set an upper limit on the exposure length

Also, remember that the values you see depend on your sky brightness, so you need to re-run the brain and re-measure the sky brightness if

* The sky brightness changes significantly - for instance new moon to full moon or transparency changes a lot
* You change equipment - ie different scope or add/remove barlow or reducer.

Hope this helps,

Robin

[eseavey]

Thanks Robin. I will try it out this weekend at my dark location.