Yep, another lens advice question

[Scott]

<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"]<o><span style="font-family: Times New Roman; font-size: small;"]</o>


<span style="font-family: Verdana; color: black; font-size: 10pt;"]Thanks Sean that is all I wanted to know, I do value your opinion and you put it in a way that makes sense.


<span style="font-family: Verdana; color: black; font-size: 10pt;"]<o></o><span style="font-family: Verdana; color: black; font-size: 10pt;"]Cheers mate<o></o>


<span style="font-family: Verdana; color: black; font-size: 10pt;"]<o>Regards </o><span style="font-family: Verdana; color: black; font-size: 10pt;"]Scott<o></o>
<p class="MsoNormal" style="margin: 0cm 0cm 0pt;"]<span style="font-size: 10pt;"]<o><span style="font-family: Times New Roman;"]</o>

[Jarhead5811]

<p class="MsoNormal"]<span style="font-family: Times New Roman; font-size: small;"]Ok, I honestly didn&rsquo;t think 7mm in a 1.6 crop...
<div style="CLEAR: both"]</div>

7mm x 1.6 = 11.2mm


Fairly significant if you ask me.

[Scott]

OK in a crop to FF mode but I'm talking 1.6 to 1.6, which is still 7mm to me ?

[wickerprints]

The difference between 17mm and 24mm is 7mm, regardless of the sensor type. However, on a APS-C sensor you will perceive that 7mm difference as roughly equivalent to a 1.6*7 = 11.2mm difference for someone with a 35mm camera were they to switch between lenses of focal length 27.2mm and 38.4mm. That is what was meant.


But really, the focal length difference between 17 and 24mm is significant not because it differs by 7mm, but because at the wide end, each mm of focal length impacts the angle of view far more than at the telephoto end. For instance, going from 20mm to 16mm will be a very noticeable change in the angle of view, compared to 200mm to 196mm, which is almost negligible.

[Jarhead5811]

I guessI think in equivalents. A 7mm difference on a crop isthe equivalent to a 11.2mm difference on a FF. 17mm being equivalent to 27.2mm and 24mm being equivalent to 38.4mm.