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Old 29-06-2015, 10:20 AM
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Shiraz (Ray)
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Quote:
Originally Posted by Slawomir View Post
Very interesting thread.

Just wanted to add, that for drizzle algorithm to work dithering may not be needed with less than perfect guiding, as there will be some variations between the sub frames anyway.

Also, although it does not relate to sensitivity, but it might be useful to be aware of the fact that binning will also increase well depth given that camera allows to adjust gain. It can come in handy when using a CCD with small pixels and thus shallow well depths.
agreed, but the practicality of binning (as Greg pointed out) is compromised by chip design. Although adding together the outputs from 4 full pixels increases the well depth, that extra charge often cannot be squeezed through the transfer registers. Chip designers seem to compromise by making sure that the registers can carry about half of the 2x2 binned full charge and they can also halve the gain to protect the dynamic range in the ADC. The read noise is also generally compromised a bit (it is usually more than that from a 1x1 read). What you often end up with is about 4x the charge at low levels, more read noise, half the gain and about 2x the effective well depth.
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