Beginner Lens

Roy1212

Roy1212

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Roy Newport
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As I wait my new 24-105 f4 lens today bought on the advice of the great people on this site my question now is (advice again sorry)which affordable wide angle lens would be a good fit for my 7d mkii.
I've been looking at the 11-16 Tokina about £300 or the canon 10-18 for £181 from Jessops less £25 cash back any thoughts appreciated.
 
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Sigma 12-24mm :D A stunning lens with negligible distortion and it'll work on APS-C and FF too :D
 
Sort of understand,Went into Jessops yesterday to buy filters for my new 24-105 and had a look at the canon 10-18,I didn't realise a Canon 10-18 which doesn't fit a full frame and was made for cropped cameras like my 7d mkii isn't really a 10-18 confusing or not?
 
Because a crop sensor is smaller than a full frame sensor, the focal length of a lens differs between the two. If you are using a lens on a crop camera like your 7D, then multiply the focal length of the lens by 1.6 to get the equivalent focal length on a full frame camera. For example, the 10-18mm on crop, the equivalent focal length on full frame would be 16-29mm.
 
I sort of understand that but it's made for a cropped camera so why not call it a 16-29 instead of calling it a 10-18
 
All the mm are based on 35mm focal lengths wether it be a point and shoot crop or FF lenses, its done this way to avoid confusion. as some lenses can be used across FF and crop.
 
Royroy1111 said:
I sort of understand that but it's made for a cropped camera so why not call it a 16-29 instead of calling it a 10-18
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Because it is still 10-18mm lens. If it was 10-24mm for example, at 24mm it would give the same field of view as your 24-105mm at 24mm.
The crop sensor to full frame comparisons are not really useful unless you are using both systems or you want to emulate the look of one with the other.
 
So my sigma 10-20 is not really a Sigma 10-20?
One more question please is my sigma 10-20 4-56 dc hem rated as a lens or not? Or should I upgrade.
 
Just taken in my back garden with the Sigma 10-20,first time I've used it as I'm getting a bit of a lens snob,is this lens good enough for landscapes for me? I could save some money.View attachment 42786
 
Royroy1111 said:
So my sigma 10-20 is not really a Sigma 10-20?
One more question please is my sigma 10-20 4-56 dc hem rated as a lens or not? Or should I upgrade.
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Of course its a 10-20mm, why wouldn't it be???
Never used one, but the Sigma has a good reputation and is often recommended, along with the Tokina 11-16mm.
 
zicklurky said:
Because a crop sensor is smaller than a full frame sensor, the focal length of a lens differs between the two. If you are using a lens on a crop camera like your 7D, then multiply the focal length of the lens by 1.6 to get the equivalent focal length on a full frame camera. For example, the 10-18mm on crop, the equivalent focal length on full frame would be 16-29mm.
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The focal length doesn't change at all, it remains the same irrespective of the sensor size. It's the field of view that changes.
 
Royroy1111 said:
Just taken in my back garden with the Sigma 10-20,first time I've used it as I'm getting a bit of a lens snob,is this lens good enough for landscapes for me? I could save some money.
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Just remember not to go silly with the aperture. The Sigma is very good at sensible apertures but it's not unusual for them to be asymmetrically soft when stopped down too far (one edge being softer than the other). But there is no sensible reason to ever stop down an ultra-wide lens beyond f/8. Most of the time f/5.6 is more than sufficient.

(if you want to know why going beyond f/8 is unnecessary, look up the depth of field and hyperfocal distances for the range of focal lengths covered by an ultra-wide lens)
 
the 10-20 is fine for landscapes, i used canons 10-22 however there wasn't much between them and certainly those that i knew that had the sigma were more than happy with the results.
 
By the way, an ultra-wide is often the least suitable/most difficult lens to be successful with for landscapes. A short-tele can often be far more adaptable unless you have a specific wide view in mind. My general purpose landscape lens is 35-70mm (on APS-C) and it's more often too short than too long for the image I see within the view. YMMV.
 
Royroy1111 said:
Sort of understand,Went into Jessops yesterday to buy filters for my new 24-105 and had a look at the canon 10-18,I didn't realise a Canon 10-18 which doesn't fit a full frame and was made for cropped cameras like my 7d mkii isn't really a 10-18 confusing or not?
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It is the same. Stop listening to people who haven't got a snooty talking about crop factors. It's my pet hate because people like you with one camera and one set of requirements shouldn't be confused by thinking about what a focal length means on a different format camera.

Just for clarity, the focal length is a measurement. It's not something that ever should have a crop factor equivalent mentioned, a typical Std focal length for APSC is 30mm, for full frame it's 50mm, for medium format it's 80mm. In the good old days, the marketers didn't talk about crop factors (to make it easy to understando_O) and no one ever got confused. Go figure! :confused:
 
Phil V said:
It is the same. Stop listening to people who haven't got a snooty talking about crop factors. It's my pet hate because people like you with one camera and one set of requirements shouldn't be confused by thinking about what a focal length means on a different format camera.

Just for clarity, the focal length is a measurement. It's not something that ever should have a crop factor equivalent mentioned, a typical Std focal length for APSC is 30mm, for full frame it's 50mm, for medium format it's 80mm. In the good old days, the marketers didn't talk about crop factors (to make it easy to understando_O) and no one ever got confused. Go figure! :confused:
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Disagree. The only thing more confusing than understanding crop factors is not understanding crop factors. It's essential knowledge for anyone looking to buy a lens - as this thread, and dozens of others, bears witness ;)
 
And the misunderstanding is only perpetuated by the confusion of thinking something about the *lens* changes.

A better way of concisely explaining what's happening is required, one that firmly puts the understanding back onto the sensor and not the optics.

But I'm also of the opinion that this is a minor issue that's blown out of all proportion on too regular a basis - it's not something that's important to good photography because it's purely a sensor size issue, which itself is not important to good photography.
 
Sigma 10-20mm. I used to have it on my canon 60d. Only sold it as I moved to full frame
 
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Love mine

MOD EDIT: STOP SPAMMING THE FORUM TO GET BACK INTO THE CLASSIFIEDS.
 
24mm is 24mm whatever body you put it on. All that changes is the amount of the image circle that is recorded.
I know its Uncle Ken but - http://www.kenrockwell.com/tech/crop-factor.htm

However - certain lenses are specifically made for crop sensor bodies and project an image circle that will not cover a full frame sensor giving darker edges. A lens made for a full frame body can however be used on a crop sensor body with no adverse effect.
Sigma for instance designate their crop sensor only lenses with the letters DC so they should not be used on a full frame body. Sigma lenses designated DG however are designed for a larger image circle for full frame and can also be used on a crop sensor body.

I hope that makes some kind of sense :)
 
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HoppyUK said:
Disagree. The only thing more confusing than understanding crop factors is not understanding crop factors. It's essential knowledge for anyone looking to buy a lens - as this thread, and dozens of others, bears witness ;)
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I respectfully disagree. The OP needed something wider than his 24-105 (for his 7dII), he considered an 11-16 Tokina or the canon 10-18. All perfectly good and straightforward.

Then he went into Jessops and was confused because the salesmen inferred the 10 to 18 'isn't really a 10-18 confusing or not?'.

There was no confusion till Jessops badly explained the crop factor to him instead of just taking his money. And the lens he'd selected was a good match and exactly what he should have bought.

Even being 'helpful', if he'd had a plan to go full frame there isn't a lens that'll transfer across well - the Sigma 12-24 will fit full frame but it still becomes an entirely different thing. A built for crop UWA is the lens to buy, and that's what he wanted.
 
Phil V said:
I respectfully disagree. The OP needed something wider than his 24-105 (for his 7dII), he considered an 11-16 Tokina or the canon 10-18. All perfectly good and straightforward.

Then he went into Jessops and was confused because the salesmen inferred the 10 to 18 'isn't really a 10-18 confusing or not?'.

There was no confusion till Jessops badly explained the crop factor to him instead of just taking his money. And the lens he'd selected was a good match and exactly what he should have bought.

Even being 'helpful', if he'd had a plan to go full frame there isn't a lens that'll transfer across well - the Sigma 12-24 will fit full frame but it still becomes an entirely different thing. A built for crop UWA is the lens to buy, and that's what he wanted.
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But that's the point. There is confusion around crop factors, it gets mentioned all the time and is impossible to avoid, so it's important to understand it properly.

Referring to your previous post, crop factors were never an issue with film because 99.9% of cameras used 35mm - it was a universal format standard for decades. And it wasn't an issue for the other 0.1% because you couldn't fit those lenses to any other cameras.

Today, it's completely different - there is a multitude of different formats, four for DSLRs. Mostly, the same lenses can be freely interchanged between them, but not always! You just gotta know this stuff to make an informed buying decision. Focal length has always been our shorthand for angle-of-view (perhaps it shouldn't be!) and the crop factor is the easiest way of getting a good comparison. It also works for depth-of-field comparisons, too :)
 
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