Norme's remarks actually address Rolo's issue. He isn't suggesting a rush to rash action, but a methodical process as an informed experimenter.
He might be seeing some improvement in his planetary sketches, which are quite good considering the limited aperture he's using. But he's careful to not "over claim" without conclusive results, as a careful observer should.
The baffles are there to prevent "sky flooding" that Rolo alludes to on his ETX experiment. I can attest to this myself having picked up unbaffled ATM cassegrain "attempts" that were ill considered.
They are also present to reduce contrast loss for high ambient light conditions like middle of the day terrestrial viewing.
But also they are present to the degree of "manufacturability" of a scope, like on the f/11 C90, who's truncated primary baffle is a cost compromise. It's "flat face" gets illuminated by bright targets, and the backscatter reflects off the secondary reducing contrast, as well as other effects. I suspect that the "good enough" short baffle meant that assembly of the top/bottom halves wouldn't have to risk collision with the baffle tube, as a manufacturing loss issue.
The Questar thin, long, conical approach is an optimization (this thread is about optimization, not about selling benefits of optimization). If you take any cassegrain and examine how the baffles work (and don't work) on bright objects, some of them work quite differently than others. Sometimes this may be transferable, other times not. (I've been experimenting with 3D printed alternative baffles too.)
And like Rolo/Norme's two sides of the same "is it useful or nonsense" concern, an objective, quantitative measure is necessary. You'd like to be able to quantify scattering, diffraction, and correction changes to assess various optimization (I'll add a fourth: High order Spherical Abberation - HSA, or above the first five Siedel aberrations (google "The Five Seidel Aberrations" for more)). This is harder than it sounds to reproducibly measure (some designs, like the C9.25's slower primary, lead to less HSA).
However, manufacturers put varying degrees of work into optimizing designs for cost or performance, as well as consistent quality control/assurance. Same is true for ATM and DIY improvements.
As to why manufacturers wouldn't add an improvement ... Norme's "need" is very narrow - one scope, a narrow set of equipment he uses, at limited certain BFL's, on a limited set of targets, where he's never going to ask for a manufacturer return. The manufacturer sells to a much broader range of these with its large customer base, with a significant number of returns even in the most perfect cases. The two don't compare - once a manufacturer "fixes" on a design instance to be manufactured, that's it for the most part.
Should others rush out and cut off baffles? No, because the manufacturer addressed their need already. Should experimenters like Norme "learn" the bounds of a scope carefully? Sure - as long as they are honest with themselves about objective criteria to measure improvement/loss. And have a reversible "plan of action", because most experiments fail.
(By the way, Rolo has some of the best images I've ever seen from common SCTs - that speaks for itself as to the effectiveness of a manufacturers choice in design.) Something to measure against any "optimizations" - you'd need to exceed that quality. Yet also, one can increase contrast with sampling and scale expansion with a sensor, while with the eye it's a different game as well.
If we could accurately measure as mentioned above, good scientific method would likely be to apply the improvement to 5 or 7 prior "un-improved" scopes, then take 5-7 already optimized scopes and remove the improvement to resemble the "un-improved" ones. From this we'd look for the mode/mean of results and present error bars on them to conclude effect, possibly with images/sketches to communicate said effect in a useful way.
Even manufacturers don't often do this.
Edited by wfj, 02 June 2018 - 06:33 PM.