How do I know if my crop sensor is a factor?

[e.rose]

With all due respect...you still aren't getting it.

So my question was how do I know what Non-Canon lenses were made for a crop sensor vs. a full frame so that I can make sure I'm purchasing a lens that's going to "give" me the focal length I'm looking for (or at least as close to it as possible), because if I'm looking at Full Frame lenses, I need to take my crop sensor into account.

The focal length is in the name of the lens. If you are 'looking for' 50mm....then buy a 50mm lens. It doesn't matter which brand, it doesn't matter which designation it has (EF-S, DX, FX, SNFU)...it will be 50mm.

And the only way it 'gives' you 80mm....is if you were expecting it to have the field of view of a 50mm lens...ON A FILM CAMERA.
If you are not used to using a 35mm film SLR (or a full frame digital)....then you do not need to be concerned about the crop factor. The only reason the crop factor exists...is because it's used to compare lenses to the old standard...which was 50mm film cameras.

50mm...on your camera...should be what 50mm is to you. You don't need to think that 50mm is actually more like 80mm...and that 80mm is actually more like 128mm. That's only a comparison.

Okay, because I was confused I looked it up.

You're right about my using wrong terminology, but I'm still right in what I'm trying to achieve.

Crop Sensor (APS-C) Cameras and Lens Confusion

(^^^What I just read through.)

So the focal length is the focal length, is the focal length. I get that now... HOWEVER... the field of view, as I think you stated above, is not the same... And what I'm trying to do is get a wider *field of view* out of whatever lens I purchase...

So it still matters whether the lens is made for a full frame or a crop sensor, because if I get a lens made for a full frame I need to make sure I take my crop sensor into account or it may not be wide enough.

 

[Rosshole]

No, FX and DX are not mounts... Nikon uses a F-mount. FX is there nickname for FF models while DX is the nickname for crop sensor models.

 

[Overread]

So it still matters whether the lens is made for a full frame or a crop sensor, because if I get a lens made for a full frame I need to make sure I take my crop sensor into account or it may not be wide enough.

I think I get where you're coming from but you're wording it all confusingly like

Simply put you want a wider lens so look at the smaller focal length ranges on offer. You don't have to keep working it out in fullframe values however because you've not got a fullframe nor are you trying to specifically emulate a set field of view that a lens gives on fullframe with your crop sensor camera - you're just trying to go wide - so its no more difficult than just looking at the lenses with shorter focal lengths on offer

 

[Ouhei]

If you want wide, Tokina makes a 11-16 f2.8 for crop sensor cameras that's supposed to be amazing. I'll be renting one for an upcoming trip and possibly buying after (depending on how useful I find it). It retails for about $600.

Just read the descriptions of whatever lens you're looking at and it'll say if it's made for crop bodies or not. Full frame lenses will work on a crop body, just keep the crop factor in mind when looking at the focal lengths.

 

[e.rose]

I think I get where you're coming from but you're wording it all confusingly like

It's something I excel at. :lmao:

 

[Big Mike]

So the focal length is the focal length, is the focal length. I get that now... HOWEVER... the field of view, as I think you stated above, is not the same... And what I'm trying to do is get a wider *field of view* out of whatever lens I purchase...

So it still matters whether the lens is made for a full frame or a crop sensor, because if I get a lens made for a full frame I need to make sure I take my crop sensor into account or it may not be wide enough.

OK...you're getting there. But it still doesn't matter whether you get 'crop' of 'full frame' lenses.

If you want a wider angle lens (wider field of view)....you just have to buy a lens that has a shorter focal length.

For example, you could use the Canon 17-40mm F4 (full frame lens) and at 17mm, it's fairly wide. Or you could use the Canon EF-S 10-22mm...and if you set it to 17mm, it will give you the same field of view.

17mm is 17mm is 17mm.

Of course, the EF-S lens can zoom down to 10mm, which is much wider/shorter than 17mm, so you can get a wider field of view. But if you had a 'full frame' lens that did zoom to 10mm....it would also give you the same wide FOV.

So forget about all the letters/designations etc. If you want a wider field of view...get a lens with a short focal length. Period.

 

[e.rose]

So the focal length is the focal length, is the focal length. I get that now... HOWEVER... the field of view, as I think you stated above, is not the same... And what I'm trying to do is get a wider *field of view* out of whatever lens I purchase...

So it still matters whether the lens is made for a full frame or a crop sensor, because if I get a lens made for a full frame I need to make sure I take my crop sensor into account or it may not be wide enough.

OK...you're getting there. But it still doesn't matter whether you get 'crop' of 'full frame' lenses.

If you want a wider angle lens (wider field of view)....you just have to buy a lens that has a shorter focal length.

For example, you could use the Canon 17-40mm F4 (full frame lens) and at 17mm, it's fairly wide. Or you could use the Canon EF-S 10-22mm...and if you set it to 17mm, it will give you the same field of view.

17mm is 17mm is 17mm.

Of course, the EF-S lens can zoom down to 10mm, which is much wider/shorter than 17mm, so you can get a wider field of view. But if you had a 'full frame' lens that did zoom to 10mm....it would also give you the same wide FOV.

So forget about all the letters/designations etc. If you want a wider field of view...get a lens with a short focal length. Period.

If that is, indeed, the case, then what the hell is this all about?

(Crop Sensor (APS-C) Cameras and Lens Confusion)

See because the whole first part of that section where that illustration comes from makes perfect sense to me... however what you're saying is that it doesn't matter... which would mean that illustration is wrong.

(I'm seriously just trying to understand all this at this point. )

 

[Overread]

All the diagram is showing you is that any lens of the same focal length will give a different angle of view when mounted on different sized sensors. Now this really only comes into play if you want to emulate one format in another or if you have a prior experience of one sensor size and want to understand things in those terms.

However you've only one camera and (far as I know) no serious history with fullframe 35mm film - so in the end you're trying to compare two things, but you've only experience and use of one (the crop sensor).

 

[e.rose]

All the diagram is showing you is that any lens of the same focal length will give a different angle of view when mounted on different sized sensors. Now this really only comes into play if you want to emulate one format in another or if you have a prior experience of one sensor size and want to understand things in those terms.

However you've only one camera and (far as I know) no serious history with fullframe 35mm film - so in the end you're trying to compare two things, but you've only experience and use of one (the crop sensor).

Okay... I know what I want to ask/say based on this comment... but... you're going to have to give me a second to sort through my thoughts or it's going to come out as a jumbled confusing mess (It still might. It's a high probability that it will. :lmao: )

::stay tuned... we'll be back after this intense thought process::

 

[Bend The Light]

If someone takes some pictures from the front of the stage and I like 'em, I might say "What lens did you use...I'd like to get some similar shots".
He says "I used my 50mm"
So, I don't go out and buy a 50mm, because he's on a full frame, I'm on a crop.
I do need to think about the crop factor, and I need a 50/1.6 = 30mm. To get the same picture from the same spot with the same FoV?

If you are not comparing to someone else, then no, I'm sure it doesn't matter.

Just what I think...sorry to cut in the thread.

 

[Postman]

Now this really only comes into play if you want to emulate one format in another or if you have a prior experience of one sensor size and want to understand things in those terms.

QFT

"Effectively" the diagram is correct if you're trying to calculate the crop factor, but like Big Mike is saying it's the wrong way to look at it and he already explains why.

So it's really not gonna matter if you buy a FF lens vs a crop sensor lens(unless you're going for compatibility with your future bodies). The FOV of 50mm FF lens will look exactly like the FOV of a 50mm crop sensor lens on your camera.

 

[Big Mike]

Here...this is what you need be concerned about...

 

[e.rose]

All the diagram is showing you is that any lens of the same focal length will give a different angle of view when mounted on different sized sensors. Now this really only comes into play if you want to emulate one format in another or if you have a prior experience of one sensor size and want to understand things in those terms.

However you've only one camera and (far as I know) no serious history with fullframe 35mm film - so in the end you're trying to compare two things, but you've only experience and use of one (the crop sensor).

Okay... I know what I want to ask/say based on this comment... but... you're going to have to give me a second to sort through my thoughts or it's going to come out as a jumbled confusing mess (It still might. It's a high probability that it will. :lmao: )

::stay tuned... we'll be back after this intense thought process::

Okay... bare with me here...

18mms using an EF-S lens (made for a crop sensor) on my crop sensor camera would give me the same field of view as 18mms using an EF lens (made for a full frame sensor) on a full frame camera... correct? (If that's not correct, then I think that's where I'm getting messed up.)

Assuming that *is* correct... then if I took that same 18mm EF lens off of the full frame camera and put it on my crop sensor camera... then I'm going to end up with a field of view equivalent to that of an 28.8mm lens, rather than that of an 18mm lens... Correct? Or not correct?

And assuming that *is* correct, then using that 18mm EF lens is going to give me a less wide (smaller?) field of view than using my 18mm EF-S lens... no? Yes?

This is where my concern is. Because I know what 18mms looks like on my crop sensor while using an EF-S lens. The reason I can't use that lens is because the aperture isn't wide enough for me to use at shows very well. So I want something with a larger aperture, that's going to give me a field of view that I'm used to... so if I want the same field of view that my 18mm EF-S lens gives me, while using an *EF* lens... would I not have to go after an 11mm EF lens to achieve that same 18mm field of view I'm used to?
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Thank you for putting up with me while I apparently struggle to understand.

 

[Bend The Light]

All the diagram is showing you is that any lens of the same focal length will give a different angle of view when mounted on different sized sensors. Now this really only comes into play if you want to emulate one format in another or if you have a prior experience of one sensor size and want to understand things in those terms.

However you've only one camera and (far as I know) no serious history with fullframe 35mm film - so in the end you're trying to compare two things, but you've only experience and use of one (the crop sensor).

Okay... I know what I want to ask/say based on this comment... but... you're going to have to give me a second to sort through my thoughts or it's going to come out as a jumbled confusing mess (It still might. It's a high probability that it will. :lmao: )

::stay tuned... we'll be back after this intense thought process::

Okay... bare with me here...

18mms using an EF-S lens (made for a crop sensor) on my crop sensor camera would give me the same field of view as 18mms using an EF lens (made for a full frame sensor) on a full frame camera... correct? (If that's not correct, then I think that's where I'm getting messed up.)

Assuming that *is* correct... then if I took that same 18mm EF lens off of the full frame camera and put it on my crop sensor camera... then I'm going to end up with a field of view equivalent to that of an 28.8mm lens, rather than that of an 18mm lens... Correct? Or not correct?

And assuming that *is* correct, then using that 18mm EF lens is going to give me a less wide (smaller?) field of view than using my 18mm EF-S lens... no? Yes?

This is where my concern is. Because I know what 18mms looks like on my crop sensor while using an EF-S lens. The reason I can't use that lens is because the aperture isn't wide enough for me to use at shows very well. So I want something with a larger aperture, that's going to give me a field of view that I'm used to... so if I want the same field of view that my 18mm EF-S lens gives me, while using an *EF* lens... would I not have to go after an 11mm EF lens to achieve that same 18mm field of view I'm used to?
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Thank you for putting up with me while I apparently struggle to understand.

I hope that's correct because it makes perfect sense to me.

 

[Overread]

Okay... bare with me here...

18mms using an EF-S lens (made for a crop sensor) on my crop sensor camera would give me the same field of view as 18mms using an EF lens (made for a full frame sensor) on a full frame camera... correct? (If that's not correct, then I think that's where I'm getting messed up.)

Nopes here is where the problem lies
18mm is 18mm always - however look at the diagram again. The focal lengths are the same, but the larger sensor is seeing more the image circle that the lens is making - whilst the crop sensor sees less. Now this creates the different angle of view even though the focal length of the lens remains the same.

Now if it were an EFS lens attached the only difference is that the lens itself would cast a smaller image circle onto the film. This means that whilst it is still the same focal length its only casting an image circle big enough for the smaller sensor - the outer glass and image circle is not made. This if you were to put it on a fullframe camera body you would have strong shadows and vignetting all around the edge.