I have a Nikon COOLPIX P7700 and because it has been losing function due to wear and tear after 6 years, and I wanted a better zoom range for wildlife, I decided to get a Canon 77D DSLR so I could get myself a more powerful camera that could have a really long zoom range and be of high quality. Although the kit lens isn't telephoto, it advertises a mm range of 18mm to 55mm range while the Nikon advertises 6mm to 42.8 mm. Although 55 on Canon isn't much more than 42.8 on Nikon, I thought it would still be a little further optical zoom than the Nikon's. Yet the Nikon displays an image much more zoomed in than the Canon's (keep in mind I've disabled digital zooms for both cameras but am pushing them to their maximum zoom). How/why could this be? I'm completely lost because I thought more mm = more zoom, and in fact you're supposed to multiply 1.5x on Nikon and 1.6x on Canon, so Canon should be significantly stronger.

This picture is a comparison between the two. I've digitally zoomed into both photos to show them at equal size. As you can see there's more grain and warp on the Canon photo because I had to digitally zoom in more, as the optical zoom was weaker (and my question is: why was it weaker if it was 55mm vs Nikon's 42.8mm?)

Thanks for the help!

On the left, Canon, on the right, Nikon

  • \$\begingroup\$ The suggested duplicate does ABSOLUTELY NOTHING to allow the OP to find an answer to his question as long as the mistaken assumption demonstrated in the OP that the Coolpix P7700 has a crop factor of 1.5X is not addressed. \$\endgroup\$
    – Michael C
    Jun 24, 2018 at 21:36
  • \$\begingroup\$ I see absolutely no reference in the "duplicate" question and answers that inform the OP that his Nikon Coolpix P7700 has a crop factor of 4.7X, rather than 1.5X. \$\endgroup\$
    – Michael C
    Jun 24, 2018 at 21:39

1 Answer 1


The difference is described by the so called crop factor. The Coolpix P7700 has a much smaller sensor compared to the EOS, thus it will photograph only a smaller section at the same lens focal length. In this case the sensor is so much smaller that it actually looks like it has a focal length longer than the longer actual focal length of the EOS. You basically have to apply a sensors size in the form of the crop factor to the focal length of the lens (and consequently also to the aperture) in order to arrive at the actual, effective focal length.

Your Coolpix P7700's smaller sensor has a crop factor of about 4.67X, compared to the canon's 1.6X crop factor.

When both are 'normalized' to their 35mm/FF angle of view:

  • The 6-42.8mm lens on the Nikon gives a 28-200mm "equivalent" angle of view
  • The 18-55mm lens in the Canon 77D gives a 29-88mm "equivalent" angle of view

To get an equivalent angle of view to 42.5mm with your Coolpix P7700, you need a 125mm lens for your 77D.

You have a couple of relatively low cost options for your 77D:

  • An EF 55-250mm f/4-5.6 lens for your 77D would give you a 35mm "equivalent" angle of view of 88-400mm, which would be roughly twice the "zoom"¹ (magnification) of your Coolpix P7700 when both lenses are zoomed all the way in and images from both are viewed at the same size.
  • An EF 70-300mm f/4-5.6 lens for your 77D would give you a 35mm "equivalent" angle of view of 112-480mm, which is roughly 2.5X the magnification of your Coolpix P7700 when both are viewed at the same size.

There's also the Canon 75-300mm f/4-5.6, but it's not a very good lens.

¹ This is an intentional misuse of the word "zoom" to match the way you use it, which doesn't mean what you seem to think it means.

  • \$\begingroup\$ Why is the 75-300mm much worse than the 70-300? Is it just because the 70-300's USM has better sound? Sorry, I'm a beginner at photography. Thank you so much for the help with my question! That was a super thorough answer! :) \$\endgroup\$
    – Zechla
    Jun 25, 2018 at 5:37
  • \$\begingroup\$ @Zechla The various lenses have totally different optical formulae. The EF 75-300mm f/4-5.6 III has 13 elements in 9 groups. The EF 70-300mm f/4-5.6 STM has 17 elements in 10 groups. The older EF 70-300mm f/4-5.6 IS had 15 elements in 10 groups and traces its lineage back to the EF 75-300mm f/4-5.6 IS (which is a totally different lens than the non-IS 75-300s). And while numbers of elements/groups, in and of itself, does not necessarily define which lens will be better, in this case the current 70-300mm and 55-250mm offerings are considerably better performers than the current 75-300.. \$\endgroup\$
    – Michael C
    Jun 25, 2018 at 7:22
  • \$\begingroup\$ ... in terms of optics especially at 300mm, which is where it sounds like you would be most interested in using a telephoto lens. \$\endgroup\$
    – Michael C
    Jun 25, 2018 at 7:25

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