Evolux 62ed producing deep blue stars advice needed. Please help

[FLO]

16 hours ago, Chibster86 said:

I've now decided to reach out to FLO to have the scope examined.

Hi 🙂 

There isn't much we can add to what has already been said.

Others in this discussion have correctly explained the colour fringing you see is only the usual 'blue bloat' associated with fast, compact, affordable ED doublet telescopes. (True apochromats have different specifications and/or cost considerably more). 

The solutions suggested by others - filtration and post-processing - are also good. 

On 16/01/2023 at 21:28, Adam J said:

Manufacturer's have started to really push the limits of what they can get away with calling apochromatic in recent years. 

We agree. 

To be fair. All things considered. Evolux telescopes are popular and perform well. 

HTH, 

Steve 

[Skyline]

It could also be down to the reducer you was using, the SW version also has an ED element.

[Oxize]

@FLO I had an conversation with Stargaze about this also. Neither me (Evolux 62ED), and he (Evolux 82ED) have that blueish tint also. 

Below an 60 second light of M31. Red channel is elavated which you see in most lights.

 

 

And its not an Achromat. Even FLO is telling me now that they dont consider this an REAL APOCHROMATIC. Guys really. The scope cost like 450 and 300 for the flattener. An simple 72 Achromat you get for underless than 200 dollar. Dont make you own versions of this scope. There is no scope between an Achromat or Apochromat. I can surely accept this will be cheaper glass with Apochromat lenses (FPL51/FK-61/FCD-1?). Lichtenknecker would never use BK7/F2, ZK9 or ZF4 achromatic glass in these scope. 

 

My guess is FK-61, FPL51 or FCD-1. All classed as real APO EDs.  And if you want to be sure, we need somebody with an spectrometer. I

 

Ive contacted Lichtenknecker also and they said the following:

 

"refractors are designed with the lenses available, taking into account the wishes of the modern user (fast opening ratio).

There is a big myth that is perpetuated on the net that only FPL53 offers the best color correction, I say this is not the case, only the combination of different glass types is relevant. There are Takahashi top models where no FPL53 can be found (or its equivalent from Hoya etc). It is therefore one of the arts of the trade to find those combinations. That is why Skywatcher does not communicate about this.

Specifically, with the Evolux series, a balance has been chosen between price and speed and use: mainly visual (2'' compatible), also photographic with reducer/corrector.

An honest visual user will find that the Evolux performs MUCH better than an ordinary achromat, because it does contain the ED glass needed for an apochromat.

The honest photographer will also notice that the even faster Evolux with its reducer/corrector gives nice pinpoint stars over at least an APS format. The thing about which a lot of ink is flowing is that with the increasingly sensitive cameras, the blue correction to the violet, which is hardly visible to the eye, is somewhat less than the much more expensive Esprit series.

The handy harry who works in our regions will therefore have no problem visually and photographically with his anti-pollution or UHC filter, and will be cheaper than the Esprit series, and faster than the Evostar series.

For 409+319=728eur you have a fast 62 ED doublet with a custom more than APS sized doublet ED reducer/corrector.

Furthermore, I do not accept unsubstantiated false accusations, and I have absolutely no problem with a third party proving that there are 2 ED APO elements in it. There is a lot of fake news on the internet..."

 

 

 

 

Edited March 29, 2023 by Oxize