How much color is too much?

I recently bought a 100mm Orion refractor for my girlfriend for her birthday. Last night was the first chance we had to use it. It had a pronounced purple halo around everything, even very dim stars. Bright objects like Jupiter and the moon were very purple. My experence to date is with reflectors, no color problems there. I know most achros have color issues, my question is, how much color is too much? Secondly, what can be done to correct the color problems as far as filters go?

Thanks for any help.
Lee

I'd say if the color bothers you, then it is too much. Some people really like their refractors and others don't because of the color... even though it is the same scope. I too use a reflector, so I have no way of comparing.

Sounds like you've got a lemon, Lee. Ask Orion for an exchange.

While there indeed is purple halo even in dim star (afterall an achromat doesn't know the difference between bright and dim objects ;-), because the brightness is low your eyes can't see it. Also, at low power, the purple (which is much less magnified would be harder to see than at high power (although this is rather obvious on Jupiter even at low power).

How much is too much? Well, we all have different eyeballs
and different sensitiviy to color. For my very small yellow eye lodged in my green skin ;-) , nothing short of APO refractor will do ;-)!

Ron the 4-inch Tall Evangelist B[ee]

After considering the advice given here and talking to Orion, I've decided the color I'm seeing isn't anything out of the ordinary. After I started thinking about it, the color halo wasn't that bad at low magnifications. I was trying to use a 2x barlow and 7mm plossl when it was at it's worst. The scope did give nice crisp views even with the halo. So based on that, I ordered an Orion V-Block filter and the gentleman I talked to told ne that if I still wasn't happy after I test the filter that I could exchange the OTA. If I'm still not happy with the performance after that I can exchange it for a comparable reflector. Orion's customer service really is top notch. I'll let you guys know what I think of the V-Block filter when it gets here next week.

Thanks to everyone for their very useful advice.

Keep looking up!
Lee

A lot depends on the individual. Some folks seem more sensitive to the out of focus red and blue that form the purple halo. When using our club's C-102, which has a focal ratio a bit less than 10 I believe, Jupiter shows an obvious purple halo. But as I use the scope, my eye/brain tends to forget the out of focus color, and it becomes much less obvious. Nice to have some built in image processing. You and your girlfriend should give the scope a good chance to prove itself - worry more about the detail you see through it and less about that purple halo.

You scope probably has the normal secondary color typical of any achromat. The secondary color is determined by the glass choices the company made. The only real way to check it is to measure the variation of focus across the spectrum using narrow band filters.

Hi Lee!

I also got the Orion 100 and the color is a recurrent issue with these scopes. Buying a MV filter is the best thing you can do, after I did that with mine I got wonderful views from it, specially after you ditch the supplied EP's that come with that scope.

You will enjoy the views much more once you get your filter, and if not, you can always return your scope.... Don't you love Orion's service?

Clear skies,
Saul

Well the V-block filter arrived today. Does it work on clouds? Wouldn't you know it, a long weekend and it's suppose to be cloudy the whole time. I have had a chance to use the scope a couple more times since the first light questions and it does deliver really good views, even in the middle of the light polluted Dallas Metroplex. I can't wait to get it to the TAS dark sky site with the new V-block filter in place. Thanks to everyone for your helpful advice.

Keep looking up,
Lee