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Which telescope is better?

Both have 60 mm diameter and 6 mm eyepiece but:

1) 600 focal length. So magnification = 100x and f/stop = 10

2) 350 focal length for magnification of 60x. But the f/stop here is 6

My feeling is # 1 because the magnification is better. FYI, the price for each one is pretty close.

What is your feeling given one has better magnification but a lower f/stop?

Update:

Sorry folks, not f/stop, but focal ratio. So I was thinking old SLR cameras with F/stops. But I meant focal ratio, the dividing of the focal length by aperture.

3 Answers

Relevance
  • 2 years ago

    60mm is a small scope. Magnification is pretty much irrelevant in such a scope. About 20X is the best useful magnification you should expect.

    If mounted on a tripod, it would give nice views of the moon, and will split binary stars for you. If the optical quality is good you should see some nice star clusters and nelulae but don't expect too much.

    I really feel that these scopes will be OK for terrestrial use such as looking at birds or ships at sea, and is certainly far better than nothing, but you will quickly find their limitations when used at night.

    OTOH, small scopes take up very little room in your closet, which is sadly where most scopes take up permanent residence, and will not be a major capital expense to lose sleep over. And if you do develop a more serious interest in observational astronomy you may be able to adapt the 60mm scope as a rather good finder scope on a larger instrument.

    But you should be congratulated on your decision to actually make some observations yourself, rather than becoming yet another couch based astronomer.

  • Tom S
    Lv 7
    2 years ago

    Other factors not mentioned are far more important than magnification, I assume you are looking at refractors, so are these achromatic or apochromatic refractors? 60mm achromatics are toys. (see 1st link) Also telescopes don't have "f/stops". I assume are are a "beginner", so study up before wasting $$ (see other links). Aperture is way more important than magnification.

    https://starizona.com/tutorial/imaging-with-a-refr...

    https://cloudbreakoptics.com/collections/best-begi...

    https://www.space.com/31229-best-beginner-telescop...

    https://astrobackyard.com/buying-your-first-telesc...

  • ?
    Lv 4
    2 years ago

    neither. a 60mm telescope is a toy. don't waste your money.

    Telescopes 101

    http://www.astronomy.com/observing/equipment-use/2...

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