Help on buying lens with crop factor consideration...

[melthazor]

So I have a 500d, which I learnt has a cropped body @ 1.6?

I'm actually considering wide angle lens. So would it be correct to say that the 10-22mm lens would be a 16-35.2mm lens instead because of the crop factor?

So would it be advisable to buy wider ones like for example a 11-16mm (or whatever they have out there)?

And wouldn't a fish eye of 8mm be 12.8mm making it less of a fish eye?

 

[Rashkae]

So I have a 500d, which I learnt has a cropped body @ 1.6?

I'm actually considering wide angle lens. So would it be correct to say that the 10-22mm lens would be a 16-35.2mm lens instead because of the crop factor?

So would it be advisable to buy wider ones like for example a 11-16mm (or whatever they have out there)?

And wouldn't a fish eye of 8mm be 12.8mm making it less of a fish eye?

11-16 is NOT wider than a 10-22. 10 < 11

Yeah, an 8mm FE would be 12.8mm, reducing the fisheye effect. That's one major reason many landscape photographers prefer full frame cameras - you get the full wideangle effect.

 

[melthazor]

11-16 is NOT wider than a 10-22. 10 < 11

Yeah, an 8mm FE would be 12.8mm, reducing the fisheye effect. That's one major reason many landscape photographers prefer full frame cameras - you get the full wideangle effect.

Ahahahaha, sorry about the mistake. 10-22mm is definitely wider.

So I guess the safest would be a fish eye lens? And maybe renting the actual lens to test it out?

 

[fmeeran]

A bit off track, but I believe Sigma has a 4.5mm fish eye for the canon.

 

[spree86]

Ahahahaha, sorry about the mistake. 10-22mm is definitely wider.

So I guess the safest would be a fish eye lens? And maybe renting the actual lens to test it out?

What do you mean by safest would be a fisheye? Don't understand that.

 

[Octarine]

So I guess the safest would be a fish eye lens? And maybe renting the actual lens to test it out?

Save for what? A fish eye is a very special wide angle lens... it's not just wider.
Yes, renting lenses is a good option. Also, do read up about wide angle lenses and composition. It's not that easy, one can easily snap a lot of empty space

 

[pinholecam]

So I have a 500d, which I learnt has a cropped body @ 1.6?

I'm actually considering wide angle lens. So would it be correct to say that the 10-22mm lens would be a 16-35.2mm lens instead because of the crop factor?

So would it be advisable to buy wider ones like for example a 11-16mm (or whatever they have out there)?

And wouldn't a fish eye of 8mm be 12.8mm making it less of a fish eye?

Yes, you need to multiply the crop factor to the focal length to get the crop focal length.
There is no ideal answer as to how wide is best. Remember that the wider it is, the greater the perspective distortion. Things in the distance gets pushed back wrt things in the foreground, which can look remote or just fine depending on what you want to achieve.

A fisheye for 35mm format will be cropped on an APS-C camera and will not be a full fisheye. A fisheye designed for digital and APS-C will be a fisheye lens.

 

[melthazor]

Ok now from reading all your replies, it seems like it doesn't necessarily mean that getting a FE would solve the crop factor issue.

That getting a FE, the pics would still be fisheye regardless, but it's just slightly cropped towards the centre?

So it doesn't mean by getting a FE, the lens would be a normal on my camera without the FE effect just because of the 1.6 cropped body? Am I right?

But for normal wide angles, the lens does in fact become less wide because of the crop body? Is there a way to counter this? By getting something that is not FE but wider than 10-22mm?

 

[NoS77]

TS, would you need such a wide angle lens?

 

[pinholecam]

Ok now from reading all your replies, it seems like it doesn't necessarily mean that getting a FE would solve the crop factor issue.

That getting a FE, the pics would still be fisheye regardless, but it's just slightly cropped towards the centre?

So it doesn't mean by getting a FE, the lens would be a normal on my camera without the FE effect just because of the 1.6 cropped body? Am I right?

But for normal wide angles, the lens does in fact become less wide because of the crop body? Is there a way to counter this? By getting something that is not FE but wider than 10-22mm?

A fisheye lens is a lens that does not have the corrective optics to make it rectilinear (ie. straight lines corrected to look straight)
There are 35mm format and APS-C fisheye lenses.
As mentioned above, using a 35mm format fisheye lens on APS-C body, image is cropped and it becomes less of a fisheye.
An APS-C fisheye will retain its fisheye 180degree FOV.

Even when cropped, it does not take away the fact that the fisheye lens does not have the corrective optics. So it will be less rectilinear than a corrected lens.
You can use a distortion correction software to correct this distortion, but in the end you loose picture quality and crop away some more of the photo.

Its not correct to say that a wide lens becomes less wide on a APS-C body.
The widest lens on 35mm format is 12mm (12-24mm)
The widest lens on APS-C format is 12mm (Sigma 8-16mm = 8*1.5 = 12mm)
If you used a 35mm format lens on APS-C body your same 12mm lens becomes 18mm
If you used the APS-C lens on a 35mm format body you get get vignetting since image circle is less than 35mm format.


In summary :
1. You want rectilinear or don't care? - ie. Rectilinear = non-fisheye UWA (10-22; 10-20; 12-24, etc); Don't care = either
2. You absolutely need 180deg FOV? - If yes, likely the fisheye. With UWA lens you need to do a panoramic stitch
3. If you want the widest rectilinear lens the Sigma 8-16mm is the answer. Else any of the UWA zooms that goes to 10mm (eg. 10-20mm);
Don't worry about possibilities of going wider and such. Since not possible unless you are ok with the distortions of a fisheye lens.

 

[Prismatic]

You have to consider what you will be using the WA for, actually, anything less that 50mm on full-frame is already
considered a wide angle. The lenses that we are discussing here are in the realm of ultra wide-angles. For most camera
brands, the range of lenses for normal use ends around 16mm. Beyond which, the lens available become more specialist
and more expensive. You can capture a wider angle of view yes, but details in the photo become smaller and also more
distorted towards the edges. sometimes it becomes so distorted when you shoot from certain angles, you have to consider
whether it's worth the effort to correct the distortion in photoshop later. My advice will be go rent out the lens and try to see
if you like the perspective first before you commit the moolah.

 

[ZerocoolAstra]

Ok now from reading all your replies, it seems like it doesn't necessarily mean that getting a FE would solve the crop factor issue.

That getting a FE, the pics would still be fisheye regardless, but it's just slightly cropped towards the centre?

So it doesn't mean by getting a FE, the lens would be a normal on my camera without the FE effect just because of the 1.6 cropped body? Am I right?

But for normal wide angles, the lens does in fact become less wide because of the crop body? Is there a way to counter this? By getting something that is not FE but wider than 10-22mm?

TS, what a cropped sensor does is capture a smaller portion of the image as compared with a full-frame sensor, or 35mm film.
I believe the image below should explain the concept quickly and easily.

taken from http://www.kenrockwell.com/tech/images/crop-factor/35mm-frame-crops-460-px.jpg

Green = Canon 1.3x crop (APS-H)
Red = Nikon DX 1.5x crop (APS-C)
Blue = Canon 1.6x crop (APS-C)


The image formed by the lens is commonly referred to as the 'image circle'. For a full-frame lens (eg. Canon's EF lenses), the image circle is large enough to cover the full frame sensor completely. An APS-C lens (eg. Canon's EF-S lenses) has the image circle large enough to cover the APS-C sensor only (red/blue rectangle) but usually not the full-frame sensor.

Some fisheye lenses are designed specifically for the APS-C sensor, because the extreme distortions at the corners may be desirable for certain applications.

 

[melthazor]

A fisheye lens is a lens that does not have the corrective optics to make it rectilinear (ie. straight lines corrected to look straight)
There are 35mm format and APS-C fisheye lenses.
As mentioned above, using a 35mm format fisheye lens on APS-C body, image is cropped and it becomes less of a fisheye.
An APS-C fisheye will retain its fisheye 180degree FOV.

Even when cropped, it does not take away the fact that the fisheye lens does not have the corrective optics. So it will be less rectilinear than a corrected lens.
You can use a distortion correction software to correct this distortion, but in the end you loose picture quality and crop away some more of the photo.

Its not correct to say that a wide lens becomes less wide on a APS-C body.
The widest lens on 35mm format is 12mm (12-24mm)
The widest lens on APS-C format is 12mm (Sigma 8-16mm = 8*1.5 = 12mm)
If you used a 35mm format lens on APS-C body your same 12mm lens becomes 18mm
If you used the APS-C lens on a 35mm format body you get get vignetting since image circle is less than 35mm format.

In summary :
1. You want rectilinear or don't care? - ie. Rectilinear = non-fisheye UWA (10-22; 10-20; 12-24, etc); Don't care = either
2. You absolutely need 180deg FOV? - If yes, likely the fisheye. With UWA lens you need to do a panoramic stitch
3. If you want the widest rectilinear lens the Sigma 8-16mm is the answer. Else any of the UWA zooms that goes to 10mm (eg. 10-20mm);
Don't worry about possibilities of going wider and such. Since not possible unless you are ok with the distortions of a fisheye lens.

Very informative, but a little chem...kinda roughly get what you mean.

I don't want a fisheye, don't like the distortion. I want wide angle lens, but I never considered the crop factor until I came across it. So I always thought that if the crop factor really does affect the wide angle, by getting a fish eye, it will fix the distortion but still keep it wide angle issue. I thought wrong...

How do I know if mine is an APS-C or 35mm format? I have a feeling that APS-C is the cropped body and the 35mm format is the full body dslr, correct?

So the widest would be the 8-16mm? I'm only looking to consider the widest because if I get say the 10-20/22, I don't want it to be only as wide or slightly wider than my standard lens because of the crop factor. Which makes buying the lens a waste of money, unless there is a possibility of me upgrading to a full body dslr.

So I thought if I considered the crop factor and buy a wider lens, it would almost be as wide as the initial 10-20/22 on my 500D.

 

[melthazor]

TS, what a cropped sensor does is capture a smaller portion of the image as compared with a full-frame sensor, or 35mm film.
I believe the image below should explain the concept quickly and easily.

taken from http://www.kenrockwell.com/tech/images/crop-factor/35mm-frame-crops-460-px.jpg

Green = Canon 1.3x crop (APS-H)
Red = Nikon DX 1.5x crop (APS-C)
Blue = Canon 1.6x crop (APS-C)

The image formed by the lens is commonly referred to as the 'image circle'. For a full-frame lens (eg. Canon's EF lenses), the image circle is large enough to cover the full frame sensor completely. An APS-C lens (eg. Canon's EF-S lenses) has the image circle large enough to cover the APS-C sensor only (red/blue rectangle) but usually not the full-frame sensor.

Some fisheye lenses are designed specifically for the APS-C sensor, because the extreme distortions at the corners may be desirable for certain applications.

Yes it's from that picture that I kinda gathered my conclusion from.

So am I wrong to say that if mine was a 1.6x crop, then the 10-20/22mm would be less wide as the area it can capture/see is only within those blue lines as compared to the 10-22mm mounted on a 35mm full body cam...

I'm am very confused now, hahaha!

So which is it? Because from my understanding, it makes it less wide. It doesn't give you the actual 10-22mm on a cropped body. But as other members have mentioned that it isn't true to say that it makes it less wide.

Another thing, is my crop factor on the 500d a 1.6x? How do I find this out? Read somewhere that it was a 1.6x...can anyone confirm this?

 

[ZerocoolAstra]

Yes it's from that picture that I kinda gathered my conclusion from.

So am I wrong to say that if mine was a 1.6x crop, then the 10-20/22mm would be less wide as the area it can capture/see is only within those blue lines as compared to the 10-22mm mounted on a 35mm full body cam...

I'm am very confused now, hahaha!

So which is it? Because from my understanding, it makes it less wide. It doesn't give you the actual 10-22mm on a cropped body. But as other members have mentioned that it isn't true to say that it makes it less wide.

Another thing, is my crop factor on the 500d a 1.6x? How do I find this out? Read somewhere that it was a 1.6x...can anyone confirm this?

The Canon EF-S 10-22mm is designed specifically for Canon's cropped sensor cameras. As such, if you were able to mount it onto a full-frame camera (eg. Canon 5D), you would likely see a circular image with big black borders. So you're not really getting more.

Just a note: Not that long ago, a lens with focal length < 20mm was considered REALLY WIDE on a film camera. Only recently have there been more full-frame lenses in the ultra-wide range (eg. 16-35, 14-24, 12-24, etc).
My point is that 10mm on a APS-C camera already gives a very wide field of view. Just how wide do you want it to be?

 

[ZerocoolAstra]

Another thing, is my crop factor on the 500d a 1.6x? How do I find this out? Read somewhere that it was a 1.6x...can anyone confirm this?

Check check out this page
http://www.dpreview.com/reviews/canoneos500d/page2.asp
under 'lenses', there is a remark 1.6x field of view crop

 

[melthazor]

Found this: http://www.digital-slr-guide.com/crop-factor.html

So it's true to get a wider angle lens if you are using a cropped body as it will be multiplied by 1.6x.

So a 10-22mm will be more zoomed in on my cam compared to a full body slr/dslr.

Pros, correct?

 

[sinned79]

btw fisheye lens is for very specialised usage, not all like it (like myself even though i love to shoot landscapes), and not all photos from fisheye turn out nice.

and u get all sort of intended distortion from fisheye shots.

 

[sinned79]

Another thing, is my crop factor on the 500d a 1.6x? How do I find this out? Read somewhere that it was a 1.6x...can anyone confirm this?

its confirmed, no need to confirm.

XXXD, XXD, 7D - 1.6
1D - 1.3
5D, 1Ds - full frames

 

[melthazor]

The Canon EF-S 10-22mm is designed specifically for Canon's cropped sensor cameras. As such, if you were able to mount it onto a full-frame camera (eg. Canon 5D), you would likely see a circular image with big black borders. So you're not really getting more.

Just a note: Not that long ago, a lens with focal length < 20mm was considered REALLY WIDE on a film camera. Only recently have there been more full-frame lenses in the ultra-wide range (eg. 16-35, 14-24, 12-24, etc).
My point is that 10mm on a APS-C camera already gives a very wide field of view. Just how wide do you want it to be?

Ah you see, that's where I didn't know that the 10-22mm is made for cropped bodies. I read we just have to consider crop factor, even a local cam shop told me that (which isn't wrong).

It's not how wide I want it to be, I want a 10-22mm, but I don't want it ending up as a 16-35.2mm on my cam instead. And if it does become a 16-35.2mm on my cam, won't I be better off buying a 8-16mm as it would finally be 12.8-25.6mm on my cam?

But like you said, if 10-22mm is made for cropped bodies, then I still would be getting 10-22mm not more not less on my cam.

And what about sigma's 10-20mm? Same or crop factor has to be included?