GB Sports Photographer & The Panasonic LUMIX S1

Sigma 50-100mm Art Lens


Philh04 Plus
14 2.1k United Kingdom
11 Sep 2018 5:50PM

Quote:Guess what, the angle of view changes on APS-H but it doesn't get narrower, it gets wider

I really do not know if I should cry or laugh, you continue to prove that you have no idea what equivalence is....

Of course, when compared to the image from a APS-C sensor an APS-H sensor will show a wider Angle of View, I have been saying that all along, you are not proving or disproving anything... You still seem to think that APS-C is the starting point for the calculation, it isn't... the starting point is the 24 x 36mm frame.

And those illustrations are seriously flawed and should be thrown out pronto... if both examples are from a 50mm lens then the APS-C framing should be identical... just because a lens is designated as DC/APS-C does not change any physical property of the lens being a 50mm. Your illustration is impossible.

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Chris_L 5 5.2k United Kingdom
11 Sep 2018 5:52PM
LOL I've been thinking about it and I think you are right and I am wrong.

I walked away after uploading that and thought about it for a bit and I came back and you'd already bloody posted Tongue

Yes I was wrong. I had been thinking along the lines above and shouldn't have. My apologies to you Phil.
Philh04 Plus
14 2.1k United Kingdom
11 Sep 2018 6:04PM
Thank you Chris and thank you for having the graciousness to apologise. Hopefully our 'discussion' may help some understand the concept.
ChrisV Plus
12 2.3k 26 United Kingdom
12 Sep 2018 12:49AM
I think the confusion comes about when you talk about the ‘multiplier’. I got the wrong end of the stick too and thought you were talking about ‘multiplying’ from the AoV that the lens in question was designed for, rather than working backwards.

You’re right of course on the equivalence figures you give for the relative formats - I hope the OP didn’t fall into the same trap I did in thinking you were saying he’d get longer focal lengths on his APSH body (I accept you weren’t). They will of course be wider, but wider than the 80-160mm native equivalence of that lens on the APSc sensor it was designed for.
Philh04 Plus
14 2.1k United Kingdom
12 Sep 2018 5:26PM
Perhaps I should have said;

Rather than the 80mm - 160mm equivalence of that lens on an APS-C sensor you will have the equivalent of a 65mm to 130mm on your APS-H sensor.... TongueSmile
ABBOALE 1 4
13 Sep 2018 7:58AM

Quote:Phil's wrong, you won't get an effective increase in focal length.
yes i know that
ABBOALE 1 4
13 Sep 2018 8:00AM

Quote:It should work ok as the Sigma lenses are not designed with the short back focus that Canons EF-S lenses have, which is more of a problem with wider angle lenses (that is why you do not see tele EF-S lenses).

That focal length range and aperture (will be an effective 65mm - 130mm f2.34 on your 1.3 crop) could be useful as a portrait lens where any vignetting may not be important.

Perhaps outline what your uses will be.

basically i want to use it as a standard 50 for static aircraft but with a bit more reach in case i cant get close
Philh04 Plus
14 2.1k United Kingdom
13 Sep 2018 8:26AM

Quote:basically i want to use it as a standard 50 for static aircraft but with a bit more reach in case i cant get close

For that purpose I believe you will be fine, the results I have seen in the research I have done have been quite outstanding, in fact it was tempting for me too but I use FF as much as I use my 1.3 crop bodies.

Good luck and let us know how you get on.


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