Maximum magnification for planets/moon with 7"Mak

[chris shaw]

I live in the city side of Singapore (near light polluted Toa Payoh) and I have a 7" Maksutov scope. What is the maximum useful magnification I should use for planetary/lunar observation on a relatively clear night (for Singapore)?

Chris

[Lee]

I live in the city side of Singapore (near light polluted Toa Payoh) and I have a 7" Maksutov scope. What is the maximum useful magnification I should use for planetary/lunar observation on a relatively clear night (for Singapore)?

Chris

Highest I tried on the 7" probably 350-400x and that's on the Moon.
With better eyepiece and when objects at higher altitude you probably
could go higher .

[weixing]

Hi,
Normally, you shouldn't exceed 300x for best image quality regardless of how big your telescope aperture. Unless, the seeing is super good, then you can try higher magnification.

Have a nice day.

[chris shaw]

So do you mean that regardless of my scope having 7" aperture or 10" aperture, one shouldn't go beyond a magnification of 300X?

At 300X magnification, my 7" scope gives a magnification of 43X per sq inch.

In your experience, is it often that you can push your scope to this level of performance or does the image get soft around 30X - 35X per sq inch? This has been my experience with my 7" Mak. I am talking about astronomy right in Singapore's city.

Chris

Chris

[weixing]

Hi,
Most of the time you shouldn't use magnification higher than around 300x, unless the seeing is super good or you are at high altitude... above most turbulence. The magnification is basically limited by seeing or atmospheric condition.

Anyway, this maximum magnification is just a guide. It can be higher or lower depend on individuals preference or tolerance ... someone can push the magnification to over 50x per inch on average seeing and they still feel OK. For example, the maximum magnification I normally use is 214x(35x per inch) for planets/moon and I feel the image is still OK, but others may think the image is a little soft.

By the way, the maximum magnification I had used before on moon was 642x(107x per inch) . The moon still can be focus and can see the moon features, but the image quality was just bad ... I never used that magnification again.

Have a nice day.

[chris shaw]

Since your magnification is 214X and its 35X per inch, I assume you have a six inch scope?

You mentioned you normally push it to 35X per inch for planets/moon but is this in your backyard in Singapore or is it in some other dark location?

Chris

[VinSnr]

I live in the city side of Singapore (near light polluted Toa Payoh) and I have a 7" Maksutov scope. What is the maximum useful magnification I should use for planetary/lunar observation on a relatively clear night (for Singapore)?

Chris

I agree that you shouldn't go above 300X for best views in Singapore.

[weixing]

Hi,
Yes. I use a 6" F5 Newtonian . I normally observe on top of a multi-storey car park in the middle of HDB flats or a slightly more dark location near a mosque.

Also, I need to mentioned that I commonly used 300x(60x per inch) on my previous 5" MCT on planets/moon... the image quality is not too bad (in my standard) .

Anyway, when observe planets and moon, light pollution isn't a much issue and you don't really need a dark location to observe, because the planets/moon are bright enough. Seeing is more importance for this type of observation.

By the way, please post equipment related question under Equipment Discussion in the future.

Have a nice day.

[MooEy]

i would say that around 200x u will already be seeing almost every bit of details on most planets. and prolly u will be getting lost in moon at that magnification.

any scope with 1/8 wave or better SA would be able to take more than 50x per inch, but the main challenge is not optics, but rather the seeing. not saying that ur scope is unable to take the magnification, but rather the atmosphere will give up before ur scope does.

~MooEy~