OK here are all the factors I find helpful in observing details on Venus....
I find the W47 violet filter to be very useful on Venus, I do sometimes use the W29 deep red filter but to me there is never as much detail with this one. Other observers report different results and I suspect that I am more sensitive to the violet end of the spectrum than to the red end.
David Gray uses a stack of green filters to good effect in his Venus observations.
You could try different colours and see what works for you.
The filters not only restrict the light to one part of the visible spectrum, but importantly they reduce the brightness of the image so that it is possible to see the very subtle variations in brightness of the cloud tops. Using a dark filter (appropriate to your telescope aperture) really helps.
I use an apoziser which I find always improves the image steadiness no matter what the conditions are like, but has the side effect of reducing colour saturation. Apodisers work better on larger telescopes. I also have one for my 5" mak but it doesn't improve the view in that telescope at all. I would think that using one on your 8" would be of some benefit.
For a year now I have been using an Atmospheric Dispersion corrector, and have found that it improves image sharpness on every planet I use it on, even Uranus and Neptune showed a clear benefit and they were quite high in my sky. For lower altitude observing the ADC is excellent in all telescopes, it can transform an unobservable ball with bad colour dispersion into a pretty decent disc.
I have also used a range of telescopes on Venus. 5" Maksutovs, 8" Newtonians, 12" Newtonian. The larger aperture telescope always wins on planets. I only own a smaller scope for occasions when I can't point my large scope at the planet I want to observe so I must travel to different location with a better horizon.
Lastly I always try to observe when Venus is high in the sky. I start before sunset (making sure the sun is behind a building) using go-to, or setting circles, or even just a digital angle finder to point the telescope in the right direction. You need the best seeing you can get.
Edited by chrisrnuttall, 24 January 2020 - 04:24 PM.