Re: Sigma 18-35 F1.8 -Absolute Magic!
 

Thanks for the info, Chris. I took the plunge and just purchased a Metabones adapter (NEX to EF), Tokina 11-16 f2.8 and Sigma 18-35 F1.8. I feel that these two lenses and the stock lens will work nicely for the majority of shooting situations.

Now for the excited wait for the courier man to arrive ;)

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

Sounds great Jody

The Tokina is also an awesome lens!! Great for Real Estate work .. if you are doing video in houses just open it to F2.8, and at 11mm then leave the cam on auto and set the focus to 0.7m and you can rush around filming the house with a point and shoot camera as everything is in focus from 2' to infinity!! When mine was stolen I was going to replace it but found a Nikon 10-24 which is also nice and was nearly new at 1/2 the cost so I grabbed it!!

The Sigma is a neat lens too ..you just have to be a little careful and use focus peaking especially at 35mm as the DOF drops right down to around 23" if you are 10' away from the subject ... It's a little tricky trying to follow focus at 35mm so I cheat and go to 18mm and just get in closer!

Let us know your thoughts?? Is the Metabones a Smart Adapter or a Speed Booster??

Chris

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

Thanks Chris. It's great knowing the Tokina is going to be so easy to set and forget.

I got the Metabones Smart Adapter.

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

I will put my question here. I'm interested in this lens but I want to know how this compare against a fullframe lens F1.4 24mm ?? (I have a samyang T1.4 24mm)

Put on the nex-ea50 it is not a 24mm. So I will loose some light when I do this?

Will this sigma be better in low light?

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

The focal length has nothing to do with the low light, the f-stop does, the sigma is a f1.8 and the samyang a f1.4 so the samyang will perform better in lowlight but just a little bit, the sigma however has a constant f1.8 throughout the zoomrange making this lens a better choice for run and gun and if you add a speedbooster you gain on the wide end so it becomes a very versatile lens in smaller spaces, you also gain a stop I believe in low light but f1.8 is allready very fast.

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

i believe the speedbooster only works with full-frame lens, 18-35mm is APS-C.

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

Correct me if I'm wrong, but I believe that there's 2 types: The regular speedbooster allows an APS-C lens to be attached to an APS-C camera (i.e EF lens to E-Mount body). But the new speedbooster Ultra looks like it is for attaching full-frame lenses to an APS-C camera.

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

here is the metabones "smart adapter" that only adapt the mounts with electronics but with no lens on it (support EF and EF-S lenses):

Metabones®

and the metabones Speed Booster ULTRA (new version of Speed Booster, support EF lenses only as the old one):

Metabones®

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

Not to get off subject here, but I have been following this thread and I plan to get this Sigma lens. I notice that both of these Metabones say they work with:

SP 24-70/2.8 Di VC USD A007 (Ver.15)

Which I think this is the lens. It is a full frame lens.

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

I'm still waiting if someone can explain me why a 3x 1/3inch camcorder can perform better in low light than the nex-ea50 with a fast 1.4 lens on it.

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

Hi Tom

It's all to do with light collection and the number of pixels on the chip area. Because the EA-50 uses a big sensor it has a high density of pixels to achieve a high still resolution (16.5mp) the humble little camcorder has a much low density of pixels on it's chip (2.2mp typical) so although it's a much lower resolution the pixels are bigger and better light collectors so the small camcorder is quite often better in low light than the more expensive big sensor cameras.

Chris

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

Chris,

I always read how bigger the sensor, the better it performs in low light. Now I'm totally confused after reading your message.

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

Hi Tom

Nope .. if you have a cluster of say 500,000 pixels on a chip they each are that much each physically bigger than a equally sized chip with say 2,000,000 smaller pixels ... the bigger pixels have a better light "gathering" capability (same as animals with BIG eyes see better in the dark)

The issue of course is that a sensor with only 500,000 pixels produces a very bright picture BUT the resolution is poor so your image quality is poor. The chip with 2,000,000 pixels is not as good in low light but has 4 times the resolution so you get a sharper image but it needs more light.

1080 video technically only needs around 2 mp resolution so a chip with 2,000,000 pixels works well. The EA-50 has a staggering 16.6 million pixels ..high resolution and to compensate for the poor low light if they tried to fit them on a 1/3rd chip (which they cannot) is why they are on a bigger sensor. Sadly each sensor is still smaller than sensors on 1.3rd chip cameras so low light suffers a bit unless you use a very fast lens.

Chris

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

Noa,

I discovered this video


A full frame lens on a APS-C sensor does change the focal length but also the aperture!
So in my case the samyang F1.4 becomes a F1.4 x 1.6 crop = F2.24 on my nex-ea50.
So the sigma will be better in low light and has a "small" zoomrange and wider angle.

Re: Sigma 18-35 F1.8 -Absolute Magic!
 

You are not understanding it right, what he compares in the video is the difference between full frame, aps-c and m4/3 sensors which all have different cropfactors giving you a different frame on the same lens and which also affects the dof and how shallow that will be. No matter what type of lens you put on your camera, f1.4 stays 1.4, it will not be more light sensitive.