Owner's manual

Handbook for the SXVR-H814C Issue 1 February 2013

another ‘Normal’ stretch, in which you bring down the ‘White’ slider to just above the

main image peak. The best setting for this is rather more difficult to guess and you

may need several attempts before the result is ideal. Just use the ‘Undo last filter’

function, if necessary, to correct a mistake. Normal (linear) stretches can give a nice

result on many objects, but you may find that bright areas ‘burn-out’ badly with this

function. It is often much better to use a ‘Non-linear’ stretch to compress the brighter

regions, while expanding the faint data. Here is the result of a non-linear stretch on

the M42 image:

The image now looks quite impressive and I hope that you like this result from this

simple processing.

Further small refinements are usually possible and you will become expert at judging

the best way to achieve these as your experience increases. As a rough guide, the

‘Filters’ menu can be used to sharpen, soften or noise reduce the image. Strong ‘High

Pass’ filters are usually not a good idea with deep sky images, as the noise will be

strongly increased and dark rings will appear around the stars, but a ‘Median’ filter

can remove odd speckles and a mild ‘Unsharp Mask’ (Radius 3, Power 1) will

sharpen without too much increase in noise.

Other things to try, include summing several images for a better signal to noise ratio.

Summing can be done in the ‘Merge’ menu and involves loading the first processed

image, selecting a reference point (a star) then loading the second image and finding

the same star with the mouse. Once the reference is selected, you can either add