difference between 200mm and 300mm negligible?

[bomberman]

I've just been out in the garden with a sigma 28-300mm lens and a tripod. This is the first time i've used anything over 70mm. There is hardly any difference between 200mm and 300mm! I got this lens for buttons as the AF is broken. Is this normal?

 

[sammyd56]

Not negligible by any means, but perhaps smaller that you would expect. Have a look for yourself:

http://lens-reviews.com/Technical-Talk/Technical-Talk/Lens-Field-of-View-Visualisation-Tool.html

 

[Tirpitz]

using that just makes me want full frame

 

[bomberman]

i was about 8m from a tree taking pictures of the bird feeder. It struck me that rather than having a sigma 28-300 with broken AF, i'd rather have a canon 70-200 f4 and crop right in. Better still a 15 megapixel 50D and canon 70-200 and crop right in.... And better still a 7d and 100-400! AND crop!

using that just makes me want full frame

me too! 5d mkII AND a 100-400! (and crop )

 

[HoppyUK]

Look at the percentage difference between the focal lengths - it's an easy shorthand. 200mm to 300mm is 50%, whereas 25mm to 125mm is 500%.

And don't be fooled into thinking that cropping with a high mega-pixel camera is any substitude for getting the right lens in the first place. It just doesn't work out that way. Having a big sensor is much better than a small sensor with loads of pixels crammed on to it.

Cropping like that is basically what digi-scoping is about - sticking a long lens on to a compact. The results are naff.