# 7Dii AF performance



## darth mollusk (Oct 17, 2014)

After looking at the specs and reading the reviews I have no doubt that the 7Dii will be a massive improvement in AF over its predecessor (the 7D) - certainly if you own any of Canon's exceptional telephoto lenses. I own the 7D and a good copy of the Sigma 120-300 os (the latest version before Sigma introduced the S). As many others have previously noted - the auto-focus speed is reasonable (but certainly not Canon L fast) and often very inconsistent, especially in AI-Servo when tracking a target. This appears to be a weakness with the lens, as significant improvements were apparently made when the S version was introduced with the USB dock. In a perfect world I would sell it and buy a Canon 300 2.8 - at the moment, however, I am a graduate student and that is not possible.

My question is: do you think the 7Dii would provide any significant improvement in AF performance (speed and accuracy) with the Sigma 120-300, or would I be wasting my money?


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## ajfotofilmagem (Oct 17, 2014)

Difficult question to answer. Surely, Canon designs and tests its new cameras using Canon lenses. You can not guess if your Sigma 120-300 will "improve" accuracy and speed of AF on a 7D Mark ii body. 

I believe that you should wait until 7D Mark ii arrives at a store near you, and test it with your Sigma lens.


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## 2n10 (Oct 17, 2014)

There is a chance that your 120-300 will not work with the 7D2. Apparently this has happened in the past. You may need to get the lens re-chipped to work with the 7D2.


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## candc (Oct 17, 2014)

I am thinking it will work a lot better on the 7dii. I have the s version and use it on a 70d. It works great until the light gets low then gets inconsistent. The spec on the 7dii says its supposed to be good down to -3ev which is the same as the 6d. My lens focuses much more accurately on the 6d than the 70d. I am thinking it will be just as accurate on the 7dii as the 6d. I will find out when i get mine ( i pre-ordered) and post, that should give you an indication


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## Steve (Oct 17, 2014)

2n10 said:


> There is a chance that your 120-300 will not work with the 7D2. Apparently this has happened in the past. You may need to get the lens re-chipped to work with the 7D2.



Get out of here with that garbage. Its BS and you know it.

As for whether or not the lens will perform better, no one can say for sure but in my experience the 7D had pretty lackluster AF tracking with a Canon 400 5.6 and a Canon 300 2.8, with and without extenders, so its probably not your lens. I moved to a 1DIV which has a phenomenal AF system and I use that with my 300 2.8, my Sigma 70-200 2.8 and my Sigma 300-800 and all three work fantastically. The 7DII should be even better. I would suggest running down to a camera store with your Siggy once the 7DII is released and try it out. I know that's what I'm going to do.



candc said:


> I am thinking it will work a lot better on the 7dii. I have the s version and use it on a 70d. It works great until the light gets low then gets inconsistent. The spec on the 7dii says its supposed to be good down to -3ev which is the same as the 6d. My lens focuses much more accurately on the 6d than the 70d. I am thinking it will be just as accurate on the 7dii as the 6d. I will find out when i get mine ( i pre-ordered) and post, that should give you an indication



That's one of the things I'm interested in as well. 800mm at max aperture of 5.6 makes AF a challenge for birds when the sun is down. If the -3EV center point helps with that it would be another checkmark in the "buy" column.


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## darth mollusk (Oct 17, 2014)

Cheers, thanks for the replies - exactly the type of response I was hoping for: objective opinions from photographers who own the lens (or similar). The verdict sounds promising - as suggested, I will wait and see.


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## -Gamer- (Oct 17, 2014)

This is from the instruction manual posted online, "Depending on the lens attached to the camera, the number of usable AF points and AF pattern will differ depending on the lens. The lenses are thereby classified into seven groups from A to G." 

Also of note are the AF points may or may not all be of the cross-type depending on the group the lens used falls under.

If you can, I'd try out the lens you intend to use with the 7D Mark ll first as the manual only list's Canon lenses and the groups they fall under.


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## AlanF (Oct 17, 2014)

The AF on the 7D was its weakest link. It had real problems with the 300/2.8 II + 2xTC, which is the reason I sold it for the 70D, which focuses well. There has been considerable comment here about the weakness of the 7D AF.


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## darth mollusk (Oct 18, 2014)

According to Roger at Lensrentals the Sigma 120-300 os identifies itself as a Canon 135 f2 when attached to a Canon body. http://www.lensrentals.com/blog/2012/08/canon-illumination-correction-and-third-party-lenses 

The 7Dii AF Manual lists the 135 f2 as one of the lenses that can utilize all 65 AF points as well as the centre cross type point (ie: full access to all AF functions). That's encouraging - we'll see if it actually works in November.


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## wyldeguy (Oct 22, 2014)

darth mollusk said:


> According to Roger at Lensrentals the Sigma 120-300 os identifies itself as a Canon 135 f2 when attached to a Canon body. http://www.lensrentals.com/blog/2012/08/canon-illumination-correction-and-third-party-lenses
> 
> The 7Dii AF Manual lists the 135 f2 as one of the lenses that can utilize all 65 AF points as well as the centre cross type point (ie: full access to all AF functions). That's encouraging - we'll see if it actually works in November.



I've tried using the af manual but it keeps asking for a password. Any idea what it is?


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## Hjalmarg1 (Oct 22, 2014)

darth mollusk said:


> Cheers, thanks for the replies - exactly the type of response I was hoping for: objective opinions from photographers who own the lens (or similar). The verdict sounds promising - as suggested, I will wait and see.


New 7D2 looks promising for sport shooters in particular. However, the S120-300mm(S) will need a software update most probably.


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## Andreas (Oct 28, 2014)

*7DMII Dimensions*

just a question. While looking at pictures of the 7DM2 body I see that all buttons, switches etc are in the exact same position as the 5DM3. I could not find anything different. Does anybody know if the 7DM2 is in dimensión similar ? Would it fit in the same underwaterhousing of the 5DM3 ?


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## wyldeguy (Oct 29, 2014)

*Re: 7DMII Dimensions*



Andreas said:


> just a question. While looking at pictures of the 7DM2 body I see that all buttons, switches etc are in the exact same position as the 5DM3. I could not find anything different. Does anybody know if the 7DM2 is in dimensión similar ? Would it fit in the same underwaterhousing of the 5DM3 ?



From what I've read it is slightly smaller in most dimensions. My guess is that it won't fit a 5D3 housing. I'm pretty sure Ikelite is working on a new housing for it already. they have a page with one for it but it's not finalized and they have no picture for it yet. And I think it's slightly bigger than the the original 7D so the old housing wouldn't fit either.


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## Mt Spokane Photography (Oct 29, 2014)

wyldeguy said:


> darth mollusk said:
> 
> 
> > According to Roger at Lensrentals the Sigma 120-300 os identifies itself as a Canon 135 f2 when attached to a Canon body. http://www.lensrentals.com/blog/2012/08/canon-illumination-correction-and-third-party-lenses
> ...


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