Deconvolution; before or after stacking.

[[1ponders] (Paul)]

Once for the processing gurus.

When considering using deconvolution on deep sky images, is it better to use a decon process ( LR, ME etc) after callibration and registration but before stacking and decon each separate image, or wait til after stacking and process the composite image?

[iceman (Mike)]

I do it after stacking, but i'm not sure if there's a "proper" way. I guess the danger of doing it before is that you'll bring out artifacts on each frame and then stacking them could highlight the artifacts even more.

[[1ponders] (Paul)]

That's what I'm thinking too Mike, but I was wondering if a light deconvolution might help in the alignment and the stacking process and result in a smaller star image that may be further refined by decon after stacking/averaging.

[janoskiss (Steve H)]

Given that deconvolution algorithms in general work a lot better with more signal-to-noise, I'd opt for deconv after stacking.

[[1ponders] (Paul)]

Thanks Steve.

[jase (Jason)]

Unless you're dealing with strong, clean data - *always* use deconvolution after, calibration, registration and combine functions. Steve is correct, deconvolution algorithms work best with more data. In some cases, after the combine task if your data is still faint you can always use pixel math before deconvolution to stretch your data further.

Its actually not how you use it, but when to use it. Some data types don't suit the deconvolution process. If you're trying to keep the most amount of nebulosity in an image I tend to avoid deconvolution entirely.

[[1ponders] (Paul)]

Gotcha, thanks Jase.