FAQ My Speed Boosted Canon lenses vs. native ones on the FS7, A7Rii and GH5

moldcad

moldcad

Veteran
Hi again, Guys - I need your advise :) This time about lenses.

So now I have 3 cameras (FS7 being the main one, and A7Rii plus GH5 as B-cams and/or stills cameras). For the Sonys, I have:

- the 28-135mm F4 lens (kit lens with my FS7)
- 2 Canon lenses I use with Speed Booster Ultra 0.71x

And since I already had the Canons when buying the GH5, I only bought a single native MFT lens with it so now I can use my GH5 with:

- the 2 Canons on Speed Booster XL 0.64x
- the 35-100mm F2.8 mk2 Panasonic lens

My problem is that my speed-boosted Canon lenses are rather soft at the edges when compared with both native lenses (the 28-135 on the Sonys, and especially the 35-100mm Leica on the GH5). So much so, that I'm contemplating selling both my Speed Boosters and Canon glass, and buying the 12-60mm F2.8 MFT lens for the Pana, and some wide zoom from Sony (like the new 16-35mm F2.8) for my FS7 and A7Rii...

On the other hand, while it's pleasure to pull focus on my Canon lenses - it's an awful focus-by wire experience with the Panasonic 35-100 and I suspect it would be the same with the 12-35 one...

So, before I list my 2 Canons and 2 Speed Booster for sale, please advise what you think about the idea. The Canons are the 16-35mm and 24-70mm F4Ls, stabilized lenses - their peripheral softness induced by Speed Booster adapters' glass is not that bad, but noticeable. Another obvious disadvantage is that Metabones adapters make it impossible to take full advantage of many of the A7Rii and/or GH5 features (mainly AF), but this is compensated for by the proper manual focusing... What do you think?

Piotr

PS. Oh, and of course if anyone is interested in buying my pristine 2 Canon lenses and 2 Speed Boosters, please contact me with PM
 
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I don't think the softness is induced by the booster.

The Canon's are full frame lenses, full frame lenses on a crop sensor, let alone on a m43 even with a speedbooster, is not the best idea.
It is better to use crop frame lenses on m43 with the speed booster ultra.
 
Cary Knoop said:
I don't think the softness is induced by the booster.

The Canon's are full frame lenses, full frame lenses on a crop sensor, let alone on a m43 even with a speedbooster, is not the best idea.
It is better to use crop frame lenses on m43 with the speed booster ultra.
Click to expand...

I'm curious why you'd say that, and more specifically if you could direct me to something that backs that up.
 
Sorry, but Speed Boosters (especially the 0.64x MFT one) require full frame lenses to work on those "crop sensors", as you call them...An APS-C or MFT lens would simply vignette - so the very idea of those focal reduced has been developed with FF lenses in mind...

Piotr
 
But that's about using FF lenses straight on smaller sensors - Speed Booster is exactly for taking care of that!
 
If it was quite 'quite', I'd never think of getting rid of my Speed Boosters :)

Piotr

PS. This thread is digressing; let me re-word my question to you guys:

Do you think it's worthwhile to get rid (with inevitable financial loss) of Canon glass with proper manual focusing and replace them with native lenses just because of them not being 100% sharp near the edges because of Speed Booster adapters they require?
 
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P

Speed boosters, zooms, it is all crap if you want real quality. We choose these things to make us be able to acquire content fast, reduce the number of lenses in the bag (to save our backs) whatever.

If you want real quality probably zeiss or voigtlander (or Cooke or Angie or Panavision!) primes is what you need? .. primes designed for the sensor size of the camera.

So no with the other options you consider

S
 
For video use, no - you've got a good range from 16mm upwards for an S35 sensor, even on non-focal reducer adapters. You could ditch the 24-70, as you're covered with the 28-135. Any which way, you're manually focusing, so the Canons will work just as well - and they give you the speedbooster option when you need it.

But for stills use on the A7Rii, get your wallet out. I've just made the (expensive) transition from Canon 5Diii to an A7Rii.

For stills work, I'd say Canon EF lenses will give you a sloppy experience - AF is crap, whatever adapter you use.

I've bought the 16-35/4 and 24-70/2.8GM Sony native lenses - both good quality, but crap value, compared to Canon at the mo - probably because they're so new to the market and supply is relatively low. Compare all of the new E Mount Sony lenses with their Canon equivalents, and it's the same story.

There are new Sigmas coming out in E Mount - maybe that will improve prices this next year.

Ben.
 
I'm using a speedbooster on my FS7 and frankly I've never removed it since getting the camera during shoots. To me at least with Canon L lenses I get a really nice image that is detailed yet not video sharp and it looks very natural.

I also have a small selection of E-mount lenses for use on my A7SII but I don't like what I get out of these on my FS7. So I would keep the speedbooster and Canon lenses. I'm about to ditch my 5DmkIII and only use Sony cameras but I will keep most of my Canon lenses because they are much better to work with on the FS7 than focus by wire lenses.

I would love for a lens as versatile as Canon 24-105 for use on the FS7 but I see no alternative.
 
Thanks guys - very helpful insights from all of you, and - surprisingly - quite consistent, too :)

As you said - I have most focal lengths covered with my Canon zooms (plus the 35-100 Pana on the GH5, and the 28-135 Sony on FS7/A7Rii); the slight reduction of corner sharpness introduced by Speed Boosters is outweighed by quite good manual focusing experience of the Canons. So for the highest quality work, I'll think of getting native primes for both systems. I guess this is the way to go!

Piotr
 
moldcad said:
So for the highest quality work, I'll think of getting native primes for both systems. I guess this is the way to go!
Click to expand...

Speaking of which: there is a good promotion at Son Center here on their FF lens, including primes. As you can imagine, Sony will never offer real bargains on their high-end lenses, nor do I have the cash one of them would cost at the moment. But I'm impatient to give my A7Rii a go with shooting some stills using a native lens other than the huge and clumsy 28-135mm F4 which might be good for filming, but not for stills. Here are some examples of the Sony primes I could buy now for some really good price; please tell me if any of them is worth a penny (I have no experience with stills, or prime lenses):

- SEL28F20 (plus the SEL075UWC converter)
- SEL50F18F
- SEL35F28Z

Any of them worth anything? Again, I'm aware they are the low-end - but for a kick-start, which one would/could you recommend? TIA

Piotr
 
moldcad said:
Speaking of which: there is a good promotion at Son Center here on their FF lens, including primes. As you can imagine, Sony will never offer real bargains on their high-end lenses, nor do I have the cash one of them would cost at the moment. But I'm impatient to give my A7Rii a go with shooting some stills using a native lens other than the huge and clumsy 28-135mm F4 which might be good for filming, but not for stills. Here are some examples of the Sony primes I could buy now for some really good price; please tell me if any of them is worth a penny (I have no experience with stills, or prime lenses):

- SEL28F20 (plus the SEL075UWC converter)
- SEL50F18F
- SEL35F28Z

Any of them worth anything? Again, I'm aware they are the low-end - but for a kick-start, which one would/could you recommend? TIA

Piotr
Click to expand...

http://briansmith.com/sony-a7-a7r-a7s-lens-guide/
 
I'd like to ask those who - like myself - are using their FS7 (and/or perhaps also A7Rii, or other Sony camera with phase-detection AF) for help in understanding problems I've had with my BT2 Speed Booster on the FS7 (frankly, it's also been a reason for even contemplating selling the Speed Booster along with Canon glass, and switching to native Sony lenses). Being an engineer, I’d like to understand deeper what’s going on with my BT2 adapter… Could you help me with that? Here are my observations:

- In Advanced Mode: when I set my BT2 to Advanced mode, and try to use Push AF – the results are exactly the same on my FS7 and A7Rii cameras: the lens will move back and forth and give up w/o finding the focus. However, there is a difference: when I actually start capturing a movie on my A7Rii, each time I press the AF/MF button I can hear the lens hunting for focus (not just the 2 movements I mentioned before) – and it will usually find it! On the FS7 however, even when I start recording, the Push AF behavior doesn’t change: it still is the 2 movements only, and failure to find focus… This is a fundamental difference, so please tell me: is this different behavior caused by using Phase Detection on the A7Rii, which the FS7 lacks (it can only do Contrast Detection AF)? But even so – why doesn’t it even try, but gives up after the 2 movements?

- In Green Mode: the same lens behaves the same on FS7 and A7Rii – i.e. no matter if in stand-by or recording, pressing Push AF causes not just 2 large, but many smaller movements of the lens focus motor, and the focus is usually found and locked on both cameras. However, those focusing movements are jerky and loud, and finding focus may even take several seconds! This is why I’d prefer to use Advanced mode, which works OK on the A7Rii but doesn’t work at all on the FS7 (apart from just 2 movements forward and backward, without finding the focus). So again, my question is: do the differences stem from the fact that of my 2 cameras, only the A7Rii has PDAF? If so, perhaps my adapter is not faulty after all – if it was, Push AF wouldn’t work on either camera! Is my theory right, or completely wrong?

- Last but not least: if in fact the difference in Push AF behavior between my FS7 and A7Rii is the result of A7Rii using PDAF, and FS7 – only CDAF, why does Metabones Support reassure me the BT2 Speed Booster should Push-AF successfully on both cameras? Can anyone on this Forum confirm that Push AF does actually work on FS7 also in Advanced mode ?!!! Perhaps it’s a matter of the lens being used? I have 2 Canon EF lenses: the 16-35mm F4L (which is on Metabones compatibility list for the BT2 adapter), and the 24-70mm F4L (which only is listed as “Tested by the community on A7RII for fast phase-detect AF”) – so could this be the difference? Does anyone know whether the new Speed Booster models (BT3 and BT4) are supposed to work better in this area?

I'd appreciate any insightful comments, TIA

Piotr
 
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OK - so I once again thoroughly compared the behavior of my 16-35mm F4L lens (which is listed on the official Metabones compatibility list) with that of my 24-70mm F4L one (which only has been “Tested by the community on A7RII for fast phase-detect AF”), both on my BT2 Speed Booster on the FS7. The bottom line is their behavior is identical as far as Push-AF is concerned - i.e. they find and lock the focus just fine with the adapter in Green mode (albeit with many high-precision focus motor movements, which takes time), but in Advanced mode none of them is ever able to find focus (they both only do 2 focusing movements, and give up w/o finding focus). This stays in opposition to what Metabones Support is saying about their BT2 adapter being able to perform Push-AF (which is the only kind of AF I ever need) in both Green and Advanced mode, on both the A7Rii and the FS7 (let me just remind you it works perfect on the A7Rii, though)...

So I'm totally lost now: not being able to blame a particular lens, and with the adapter acting as expected on the A7Rii but not on the FS7 - I'm reluctant to conclude it's faulty... But then again, why such an inconsistency between my two cameras?

Piotr
 
Piotr,
You are a very exacting technician though sometimes I wonder if the issues you concern yourself with are worth it. I think the general concensus regarding AF with the Metabones adapter and the FS7 is simply don't bother. Its inconsistent across various lenses and general just doesn't work and I imagine this is because the FS7 doesn't use phase detection. If its working on the A7Rii consider yourself lucky - its a bonus. The FS700 with phase detection also has much better AF than the FS7. You're right that metabones seems to make claims for AF that don't seem to hold up though. By all means keep testing this stuff if you have the time and inclination, and maybe you'll have some fantastic breakthrough that we can all profit from, but you could also forget about it and go on to more profitable uses of your time.

Regarding softness of the Speedbooster. Somewhere I saw tests by the guy who invented SB and he found that in the center , lenses using speedbooster were significally sharper than without, but that as you've mentioned , the corners were softer. So its apparently a trade off.
 
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Hi Lenny, thanks for the response. I'd have long given up and - as you say - wouldn't bother with Push AF on the FS7, were it not for Metabones themselves claiming this combo should and does work. Here is an excerpt from just one of their emails:

"I tried a good number of lenses on FS7 using FOCUS PUSH AUTO (in Advanced mode with the focus switch at the MAN position) and they all worked fine"

Go figure :(

Piotr
 
Yeah well.... I tried all of mine and it was absolutely helpless, lots of hunting and no settling to anything remotely in focus. Some lenses worked better than others but they all flat out sucked. Nobody on the boards has ever reported anything better.
 
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