# 16-35 f/4 IS for infrared?



## Duff (May 24, 2014)

Any info on how the new 16-35 f/4 IS lens works in infrared? The 17-40 did an okay job (at least it doesn't have a hotspot), but the 16-35 f/2.8II was useless in IR.


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## neuroanatomist (May 24, 2014)

I wouldn't expect any until people start getting the lens. Canon doesn't make IR dSLRs, so they're not going to test for it (and probably not include IR light in their design considerations). It's not something that can be inferred from a block diagram or MTF chart. Unfortunately, you'll need to wait until IR shooters get their hands on the lens, sometime after it's actually available.


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## Khalai (May 24, 2014)

neuroanatomist said:


> I wouldn't expect any until people start getting the lens. Canon doesn't make IR dSLRs, so they're not going to test for it (and probably not include IR light in their design considerations). It's not something that can be inferred from a block diagram or MTF chart. Unfortunately, you'll need to wait until IR shooters get their hands on the lens, sometime after it's actually available.



60Da does not count as IR camera? Just asking, I'm not much knowledgeable about astrophoto and IR photo...


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## neuroanatomist (May 24, 2014)

Khalai said:


> neuroanatomist said:
> 
> 
> > I wouldn't expect any until people start getting the lens. Canon doesn't make IR dSLRs, so they're not going to test for it (and probably not include IR light in their design considerations). It's not something that can be inferred from a block diagram or MTF chart. Unfortunately, you'll need to wait until IR shooters get their hands on the lens, sometime after it's actually available.
> ...



The 60Da still has an IR cut filter, it's just weaker in the deep red (Hα is 656nm, IR starts at ~700nm). Also, the 60Da is suited only for astrophotography, and an f/4 lens is pretty unsuitable for that application.


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## millan (May 24, 2014)

I wonder too. It prevents me to sell the 17-40 and to order the 16-35 f/4 IS. I am very impatient and curious


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## traingineer (May 25, 2014)

neuroanatomist said:


> Khalai said:
> 
> 
> > neuroanatomist said:
> ...



Unsuitable if you don't have a tracking mount.


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## Nitroman (May 25, 2014)

My gut feeling is that it will have a hotspot - much like the 16-35mm F2.8.

The older lenses seem to be better for IR as the newer ones are made to reduce IR.

But the proof of the pudding is in the testing !


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## fugu82 (May 25, 2014)

Well, I have the 24-70 f/4 IS and the 70-200 f/4 IS, both pretty modern lenses, and they play very nicely with my IR converted 40D. So there is some hope that the new 16-35 f/4 will be better than the 2.8 in that regard. Would be hard to be worse, actually. :-\


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## RLPhoto (May 26, 2014)

If I get my hands on one, I will test it on my IR T1i.


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## Duff (Jun 21, 2014)

Now that the lens is on the market, any infos on the IR performance (hotspot, focus shift, sharpness)?


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## neuroanatomist (Jun 21, 2014)

Patience, young grasshopper. B&H only started shipping it yesterday. Maybe you should take your IR camera and fly visit B&H in Manhattan...


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## Spooky (Jun 24, 2014)

oops, just spotted this thread - I just posted a new thread re IR use - this lens is very good! R72 filter and no hot spots... very clean & sharp across the frame, I used the IR focus mark on the 'window' and got very good results in strong sunlight.

Sorry about the subject matter, only a test shot!


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## Spooky (Jun 24, 2014)

Another shot this afternoon...


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## Duff (Jun 27, 2014)

Spooky said:


> oops, just spotted this thread - I just posted a new thread re IR use - this lens is very good! R72 filter and no hot spots... very clean & sharp across the frame, I used the IR focus mark on the 'window' and got very good results in strong sunlight.
> 
> Sorry about the subject matter, only a test shot!



Thank you for your time for testing it! 
I've actually hoped that it would hospot than the switch from Nikon DX to Canon FF would be out of question but now I'm facing a tough decision: 
2x Nikon D610 + 16-35 f/4VR + 50 f1.8 + 70-200 f/4VR
or...
2x Canon 6D + 16-35 f/4 IS + 50 f1.4 + 70-200 f/4 IS.
From above I only have the Nikon 70-200f/4VR so far, the rest of my gear is Nikon DX.


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## Vossie (Jul 3, 2014)

Spooky said:


> Another shot this afternoon...



Lovely shot!


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## Spooky (Jul 5, 2014)

Thank you very much Vossie...


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