How does crop factor affect my focal length?

TelePaul · 23-05-2007 5:03pm #1

I was told that the crop factor on my Canon Digital Rebel would affect my focal length, perhaps make a 50mm lens seem more like a zoom? Could someone elaborate on this?

Fajitas! · 23-05-2007 5:05pm

Yep, multiply your focal length by 1.6 to get your new length.

The smaller sensor uses a smaller portion of the lens than a full frame sensor, so works to multiply it's length.

ThOnda · 23-05-2007 5:09pm

That's what I'm worried about. My lovely 28mm is going to turn into 35 mm "toooooo long" wide lense.

TelePaul · 23-05-2007 5:19pm

ThOnda wrote:

That's what I'm worried about. My lovely 28mm is going to turn into 35 mm "toooooo long" wide lense.

But will that turn a 300mm zoom into a 480mm zoom? i.e will it have a positive effect in that case?

Fajitas! · 23-05-2007 5:22pm

Yep!

Calina · 23-05-2007 5:22pm

Yes it will.

Stephen · 23-05-2007 5:41pm

Of course, the wide end of your zoom will be that much longer as well - in my case my 70-300mm Sigma becomes a 105-450mm with my Nikon's 1.5x crop factor.

TelePaul · 23-05-2007 5:51pm

Stephen wrote:

Of course, the wide end of your zoom will be that much longer as well - in my case my 70-300mm Sigma becomes a 105-450mm with my Nikon's 1.5x crop factor.

Ah takes from the bottom and gives to the top.

Can I just see if I get this right? I like wildlife but can't get close enough without being spotted....would a 300mm lens and 1.6 crop factor allow me to take close up shots from further away? Sorry, I'm really new at this.

Fajitas! · 23-05-2007 5:53pm

Well, it would let you take photos from further away alright, but I'm not sure how far would be best - Roen is pretty into his birding (Both meanings tbh), so wait until he comes along this evening!

Calina · 23-05-2007 5:53pm

I don't 300mm(ie 450) would still be enough to be honest for birds...speaking from experience the only ones I ever got to cooperate would be pigeons and seagulls. But yeah, wait see what Roen has to say.

Roen · 23-05-2007 6:04pm

Ask Carrigman, his is bigger.

TelePaul · 23-05-2007 6:05pm

I was thinking more along the lines of deer and rabbits.

deRanged · 23-05-2007 6:44pm

Rabbits should be relatively easy, I've never tried stalking deer. Birds are tricky though.
http://www.flickr.com/photos/bcie/491581695
This might give you an idea - it's a 75-300 at 300mm lens, handheld and I reckon the bird was about 5 metres from me.

TelePaul · 23-05-2007 6:47pm

deRanged wrote:

Rabbits should be relatively easy, I've never tried stalking deer. Birds are tricky though.
http://www.flickr.com/photos/bcie/491581695
This might give you an idea - it's a 75-300 at 300mm lens, handheld and I reckon the bird was about 5 metres from me.

Very nice shot! Hmmm. Dunno about dear and foxes, I'm thinking I'll be needing a 400mm after all.

ThOnda · 23-05-2007 8:37pm

I can see lots of foxes and badgers from very short distance regulary. The distance is about two meters. I am in my car and they are lying at the edge of the road...
To be honest I don't have the patience to shoot wildlife. The longer lense, the more noisy and les patient you can be.

TelePaul · 24-05-2007 12:47pm

ThOnda wrote:

I can see lots of foxes and badgers from very short distance regulary. The distance is about two meters. I am in my car and they are lying at the edge of the road...
To be honest I don't have the patience to shoot wildlife. The longer lense, the more noisy and les patient you can be.

Thanks for the....help.

How does crop factor affect my focal length?

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