Low Light Wide Angle VS. Art Lens

[ScottS]

Could someone share their thoughts on the Canon 16-35mm f/4 lens? I've read rave reviews on several forums and photographer blogs. I'm torn between this lens and the Sigma Art 1.4. I know that they have very different functions. However, is the low light capacity of the 16-35mm f/4 good enough for lower light situations (not pitch black of course)? My shots will be of people inside buildings, beside campfires, in lower light concerts, possibly some street life shots. I have to choose ($$$) between these two for now, for financial reasons.

Really just wanting to hear your uses and results on these two lenses. I'll have to prioritize.

Thanks!

Scott S

[ebiggs1]

Always go Canon if it works and fits the bill.  You are at f4 mostly so staying there is not going to be any different for you.  The light ability is not changed by focal length or different than what you are already seeing.

"The image difference between an APS-C sensor and a FF sensor are worlds apart."

This is pure nonsense.  It isn't true so don't let it deter or convince you.

[ScottyP]

If the Canon is double the price, though, you have to prioritize. I was very willing to pay $2,500 for my Canon 70-200 (yes I know it is now cheaper) and I am still happy I spent it because the images are lovely.   For a wide angle I could not justify the Canon. Your budget probably says you can splurge on some lenses and economize on others. 

[Waddizzle]

"The image difference between an APS-C sensor and a FF sensor are worlds apart."

This is pure nonsense.  It isn't true so don't let it deter or convince you.

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I think there is a big difference.  The FF sensor in the 6D has bigger  pixels, a.k.a. "light buckets".  The pixel size of 6.55 µm.is way bigger than current APS-C sensors.  The higher S/N ratio from the larger pixels is real, not imagined.

[Waddizzle]

The angle of view on a full frame sensor body camera is much wider than with the same lens on an APS-C body.  In addition to the wider angle of view, the full frame sensor gives you dramatically more DOF.

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The image difference between an APS-C sensor and a FF sensor are worlds apart.  The laws of physics says they are.

[ScottyP]

Wadizzle:  

I think you meant to say the full frame camera gives you less DOF, not more DOF. The depth of field in focus on FF is shallower.  The FF gives stronger background blur/bokeh. 

[Waddizzle]

"

Wadizzle:  

I think you meant to say the full frame camera gives you less DOF, not more DOF. The depth of field in focus on FF is shallower.  The FF gives stronger background blur/bokeh. "  

What you say is true.....from a certain point of view.

The calculations can show that a FF sensor will have a shorter DOF if you adjust the focal length for crop factor, 50mm vx. 80mm.

[ebiggs1]

"What you say is true.....from a certain point of view."

No what Scott says is true period.  A 50mm lens on a crop is going to have less DOF than that same lens will on a FF.  The lens did not, can not change its focal length.  It is the sensor in this case that does make the difference.  It is what it is.

[kvbarkley]

DOF is related to the circle of confusion which is dependant on sensor size.

[Waddizzle]

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@kvbarkley wrote:

DOF is related to the circle of confusion which is dependant on sensor size.

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The CoC constant is used in the DoF calculation, and it is directly related to sensor size.

Like I said, it depends upon your "point of view", lliterally.  With everything else being equal, when FF and APS-C body cameras are given lenses of the same focal length, the calculations say that the APS-C sensor has the shallower Depth-of-Field. This is what my first set of DoF tables is showing.

However, when the FF and APS-C cameras are each given lenses with focal lengths [80mm and 50mm] that result in approximately the same Angle-of-View, then the FF camera body will have the much shallower Depth-of-Field.  This is what my second set of calculations are showing.

[ebiggs1]

That is not what you said!  You said....

""The image difference between an APS-C sensor and a FF sensor are worlds apart.""

And that statement is nonsense and not true.  That is reading and not doing experience.  IMHO, of course.

The size of the sensor is not the issue as you correctly later pointed out.

"The laws of physics says they are."

Right!  More than one?   How many?  I think it is the law of waddizzle