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Fast AF prime wide lense


simonko
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Hello,

 

I own an A7R2 and wondered if there was at least one decent APS-C wide lense (≤ 21 mm fullframe focal length) that is:

- a prime

- fast (at least F1.8)

- with autofocus

- E-mount or Canon EF mount (adaptable with a speedbooster or MC-11)

- not too noisy (like the Sigma art primes)

 

By decent I mean no chromatic aberration, I don't mind a little vignette or blur on the edge for 1080 video.

 

The only one I found was an APS-C 19mm, I think F1.8, with chromatic aberration.

Thank you for your help,

 

Simon

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`     

   

You're asking for a 12 or 14mm/1.8 AF lens.   

  

Rotsa ruck .... hope you've got a "Plan B" :-(   

And using Canon lenses ? Rotsa rotsa rotsa 

ruck. That is NOT a viable Plan-B. More like 

a Plan-X. 

   

It may be less expense to switch to M43 for 

your 1080 video. 20MP M43 is the same as 

shooting APS-C on an a7R-II, sensor-wise. 

   

All else is actually superior, since M43 gear 

tremendously well engineered for the pixel 

density involved, where the a7R-II is mainly 

a FF design.  

   

What is meant by "all else" ? AF accuracy, 

lens speed, EVF resolution, to name a few. 

Olympus offers a 12mm/2.0 .... 2mm longer 

than your fantasy lens, but is only $700, half 

the price of the Sigma 14mm/1.8 for Canon, 

which is the only other option and is the size 

of a large coffee mug ... the Olympus being 

the size of a shot glass. Welcome to Plan-B,   

greater realism at no extra cost.  

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Guest Jaf-Photo

I don't really understand the question. It's quite easy to find which lenses are available. Then You'll just have to choose the one that fits your requirements the closest.

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I don't really understand the question. .....

   

Agreed it's mostly full of nonsequitors, possibly 

based on reading spec's without understanding 

much ... but the one thing I'm semi-convinced is 

he wants to shoot crop format on an a7R-II with

about a 90 degr FoV. The rest, as you've noted, 

is gobbledegook. 

   

Sticking with the only thing I could decipher, he 

wants a fast APSC lens of < 20mm FF FoV. So    

there's very few choices, and he seems to have 

ruled out most of them .... due to stuff he might 

have read about them ["noisy" Sigmas, CA, etc].   

   

He's prolly better of with M43, but OTOH this is 

the Sony forum :-( Anywho, seems like he's left 

the building. 

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Agreed it's mostly full of nonsequitors, possibly 

based on reading spec's without understanding 

much ... but the one thing I'm semi-convinced is 

he wants to shoot crop format on an a7R-II with

about a 90 degr FoV. The rest, as you've noted, 

is gobbledegook. 

   

Sticking with the only thing I could decipher, he 

wants a fast APSC lens of < 20mm FF FoV. So    

there's very few choices, and he seems to have 

ruled out most of them .... due to stuff he might 

have read about them ["noisy" Sigmas, CA, etc].   

   

He's prolly better of with M43, but OTOH this is 

the Sony forum :-( Anywho, seems like he's left 

the building. 

Hi

 

thank you all for your replies

 

There are many reasons why one would want aps-c lenses for an a7r2:

- in 4K video, the image quality is better in crop mode

- they are smaller

- cheaper

- I can use it on a super 35mm video camera without losing it's wide angle feature

 

This is probably a broke-man thinking but I'm broke, so…

 

There are plenty of cheap crop and FF wide lenses but they are all manual focus, that's not optimal for gimbal filming.

 

I could also get a M43 camera that can shoot 4K, not too noisy in the dark… that's expensive and not easy to find I guess if the GH5 doesn't do it.

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Hi

 

thank you all for your replies

 

There are many reasons why one would want aps-c lenses for an a7r2:

- in 4K video, the image quality is better in crop mode

- they are smaller

- cheaper

- I can use it on a super 35mm video camera without losing it's wide angle feature

............... 

  ............................................................

     

    

Nobody questioned that idea. It's rather common practice.  

   

You can use Sony APSC lenses. 

   

In general, you CANNOT use adapted Canon EF-S lenses.    

   

Most adapters do not fit the "S" type Canon lenses. Some 

3rd party APSC format Canon-mount lenses do fit. But you 

will hate using them. Their AF is for static subjects. Action

subjects are best handled in MF. Few users have that skill.   

    

Long ago, photographers discovered that smaller cameras 

are faster. So, for action subjects, rollfilm replaced 4x5, and  

then 35mm replaced rollfilm. This rationale still holds true. If 

you want a real action-oriented system, look to M43.  

  

While there never was a Free Lunch, even expensive 35mm 

cameras were both faster and cheaper than any rollfilm gear. 

Likewise, the most expensive M43 stuff is faster but cheaper 

than 23x36 FF digital cameras. But this IS the Sony forum ...   

    

------------------------   

   

BTW, I'm not sure why you fear CA. Also, you didn't specify 

what problems you expect it to cause, nor which CA you fear.  

   

For instance, you want a fast aperture and you don't mind a 

bit of vignetting. Wellll Orvilllle .... if the corners are soft, and 

also darker, how you gonna produce the contrasty edges that 

provoke visible lateral CA ? If you have some longitudinal CA,  

how you gonna notice it on 1080 video ? 

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Won't meet your requirements fully, but have you considered the Sigma 16mm 1.4?  It is a wonderful lens, excellent value, superb image quality.  

Hello

thank you

 

why doesn't it meet all my requirements? Is it slightly too "big"?

I think I opted it out because of the alleged chromatic aberration and distorsion… perhaps it's less the case from F1.8 or F2? What's your experience?

 

But for a lack of a better choice, I might choose that one!

 

 

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Nobody questioned that idea. It's rather common practice.  

   

You can use Sony APSC lenses. 

   

In general, you CANNOT use adapted Canon EF-S lenses.    

   

Most adapters do not fit the "S" type Canon lenses. Some 

3rd party APSC format Canon-mount lenses do fit. But you 

will hate using them. Their AF is for static subjects. Action

subjects are best handled in MF. Few users have that skill.   

    

Long ago, photographers discovered that smaller cameras 

are faster. So, for action subjects, rollfilm replaced 4x5, and  

then 35mm replaced rollfilm. This rationale still holds true. If 

you want a real action-oriented system, look to M43.  

  

While there never was a Free Lunch, even expensive 35mm 

cameras were both faster and cheaper than any rollfilm gear. 

Likewise, the most expensive M43 stuff is faster but cheaper 

than 23x36 FF digital cameras. But this IS the Sony forum ...   

    

------------------------   

   

BTW, I'm not sure why you fear CA. Also, you didn't specify 

what problems you expect it to cause, nor which CA you fear.  

   

For instance, you want a fast aperture and you don't mind a 

bit of vignetting. Wellll Orvilllle .... if the corners are soft, and 

also darker, how you gonna produce the contrasty edges that 

provoke visible lateral CA ? If you have some longitudinal CA,  

how you gonna notice it on 1080 video ? 

Thanks for the knowledge!

 

I think I'm too ignorant to understand your questions.

In general I don't like the look of an image with CA. Then I don't know the process which keeps or erases CA in 4K or 1080…

Also I noticed I tend to add vignette, sometimes edge blur as well when color grading so I guess I won't fuss too much about it for now.

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