Telscope colour rendition

[Swagman105 (Geoff)]

I am currently looking to upgrade my old Vixen 80 for an APO of around 100mm to take the next step with my AP.
In researching different brands I see the term "accurate colour rendition" used as against "accurate colour correction" I would expect all quality APOs to have good or near perfect colour (chromatic) correction, so the term colour renditions seems to indicate that not all APOs are alike in terms of the transmission of different visible light wavelengths, possibly as a result of different coatings and glass. In aiming for imaging accuracy, it is hard to imagine that once lost in an optical system information can be accurately restored by an imaging system and post processing.
My question is " Is the "accuracy of colour rendition" of a telescope something measurable or meaningful and therefore something to consider when trying for the best possible images?"
I have tried to look at many images taken with different telescopes and while pleasing to the eye, almost all show somewhat different colour renditions of similar objects. Again almost all of these images have been made using different combinations of telescopes, imaging gear and processing so it is hard to isolate the effects of telescopes' colour rendition factor on their own.
Any opinions would be valued but I would like especially to hear from those who have had the opportunity to use much the same imaging gear and processing with different telescopes as to whether the "colour rendition" characteristics of different APOs is significant.

[gregbradley]

FSQ106N has different colour characteristics compared with FSQ106ED which can be a bit greenish.

Fluorite scopes tend to be more colourful. I had an FSQ106EDXiii and sold it and got a TEC110 F5.6 fluorite triplet and straight away noticed the improved colour it produced using the same cameras.

My current 105mm F6 CFF seems fine with colours as well although I haven't used it that much. But it seems to produce nice colourful images. Its an FPL55 oiled triplet.

So yes I think there are slight differences between scopes in colour transmission due to coatings and lens materials also baffling and the type of paint they may use inside the tube.

A TEC180 fluorite oil spaced triplet was quite colourful, an AP140 was less so, FPL53 oil spaced triplet.

So anything with a fluorite triplet I would rate as likely to be best at colour transmission. Even an FS152 fluorite doublet let through nice colour but it also was really semi APO with some blue rings around brighter stars due to blue being a bit out of focus as its not a true APO.

Those differences would fade away if you mainly do narrowband though.

Greg.