[jsmoraes (Jorge)]

Raymo, my theoretical resolution with my normal set: newtonian telescope GSO 305 mm, coma corrector GSO, spaced by OAG and filter wheel, skyglow filter, Canon T3 is around 0,65"/px. I believe we can think about 0,8" or 1"/px because of RMS oscillation from guiding and refraction.

Therefore, to resolve the cluster and binaries isn't problem. Since I don't use guiding to do it. Only refraction is the problem.

I used the UHC filter, instead skyglow filter. It is new for me, and I don't know exactly what resolution I have with it. Nevertheless, it seems to be very similar to the resolution with skyglow filter.

Why UHC filter ? To enhance the contrast and separation.

The image was croped to Trapezium region and it was magnified only by 1.5x (150 %). The stacked result permited it.

I did around 40 frames, I selected only the best 20 and DSS used only 17. No dark, no flat, no bias. XiDenoiser, NLM mode, was used to clean noises.

To enhance the visibility of faint stars of the cluster I used mask to increase its brightness and contrast.

The nebula was enhanced with sharp 20 pixels 30 % and Legacy Contrast for color. I used mask to act only on it.

The most difficulty was to choose the best time of exposition and ISO. You need sensibility to see the faint stars without saturation of giants ones.
There was no mathematics, it was trying-and-trying with analyse of result and selection one-by-one after.

I didn't get identify the stars H and I.