View Single Post
Old 17-02-2014, 02:37 PM
strongmanmike's Avatar
strongmanmike (Michael)
Woohoo it's clear

strongmanmike is offline
Join Date: May 2006
Location: Canberra
Posts: 14,749
Originally Posted by gregbradley View Post
I think Mike is talking about a different thing. Using a mask and blending it in lighten mode or enhancing what is there and then blending that in on the object of interest is only enhancing data that is there in the first place.

Some brush tools and lassooing can cause an artificial structure based on the borders of the selection. I take he is referring to that.

As far as R Jay goes I don't know that he adds false detail to his images but rather super heavy colour saturation and stretching to coax out every last drop. He may have features enhanced out of proportion to their relative brightness - so relative brightnesses are changed heavily
but I don't think that is creating an artificial structure that does not exist. Much like Hubble narrowband showing up structure that regular colour does not.

Don't forget he uses 20 inch RCs and dark sky sites and super long exposures with good cameras and mounts. The 20 RCOS scope is probably the most premium scope around and its too bad they went out of business, but they got some amazing data from those scopes.

Ok going a bit OT here...

One of RJ's images that had me thinking about the possible dangers of painting masks is that of NGC1097. In this (remarkable) image RJ was able to show (and very clearly) two of the jets emanating from NGC 1097.. but strangely, not the third (or VERY faint 4th). The two opposing jets visible in this image however are not the two brightest of the three jets but rather are in fact the brightest and the 3rd brightest jet, the 2nd brightest jet does not show in his image at all, even under an extreme stretch, nothing...why? This doesn 't make any sense unless there was some feature specific enhancements that were not applied to this jet, perhaps because the processor wasn't aware of its existence?.. I dunno but given the clear brightness of the other two jets it should be visible if more global attention was paid to all faint features

Also if you compare THIS version of M83 to THIS version what is going on? Perhaps this is the heavy handed application of brightness adjustments to very specific features, in this case specific areas of the galaxy arms..?

Either way and just to clarify, I am not accusing anyone of any wrong doing here I am just pointing out what in my opinion looks to be examples of what selective imbalanced and perhaps arbitrary brightness enhancements can do and thus question the accuracy and even validity of other faint features revealed in other images that were created with similar techniques

NB: I still think RJ's images are excellent of course and love his colour fidelity

Reply With Quote