Speed Booster Sigma 150-600mm

Started 9 months ago | Discussions
Aussie Coop
Aussie Coop Regular Member • Posts: 398
Speed Booster Sigma 150-600mm

Has anyone used the Sigma 150-600 Contemporary on an Eos M with the Viltrox 0.71 Speed booster ?

I read there was a vignette and Im trying to find out how much and what people thought?

The M6 is a secondary camera and Im usually using the Sigma on my EosR but was thinking the boost in light would come in handy.

 Aussie Coop's gear list:Aussie Coop's gear list
Canon PowerShot S100 Canon EOS 5D Mark III Canon EOS M Canon EOS M6 Canon EOS R +12 more
Canon EOS M6 Sigma 150-600mm F5-6.3 | C
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nnowak Veteran Member • Posts: 7,396
Re: Speed Booster Sigma 150-600mm
4

Aussie Coop wrote:

Has anyone used the Sigma 150-600 Contemporary on an Eos M with the Viltrox 0.71 Speed booster ?

I read there was a vignette and Im trying to find out how much and what people thought?

The M6 is a secondary camera and Im usually using the Sigma on my EosR but was thinking the boost in light would come in handy.

Puting a speedbooster on the Sigma 150-600mm f/5-6.3 creates a 106-426mm f/3.5-4.5 lens. When you mount this combo on an M series camera it is equivalent to 170-682mm f/5.6-7.1 on full frame.  You are basically right back where you started with this lens on your R, but with the additional image degradation caused by the speedbooster.

Aussie Coop
OP Aussie Coop Regular Member • Posts: 398
Re: Speed Booster Sigma 150-600mm
1

nnowak wrote:

Aussie Coop wrote:

Has anyone used the Sigma 150-600 Contemporary on an Eos M with the Viltrox 0.71 Speed booster ?

I read there was a vignette and Im trying to find out how much and what people thought?

The M6 is a secondary camera and Im usually using the Sigma on my EosR but was thinking the boost in light would come in handy.

Puting a speedbooster on the Sigma 150-600mm f/5-6.3 creates a 106-426mm f/3.5-4.5 lens. When you mount this combo on an M series camera it is equivalent to 170-682mm f/5.6-7.1 on full frame. You are basically right back where you started with this lens on your R, but with the additional image degradation caused by the speedbooster.

Im aware of the new focal length, but how do you come at it being f/7.1 , doesnt the booster increase light by at least 1 stop? So that would make it 682mm f/4.5 at the long end by my calculation ( far from being where it is on the R ). From what Ive read the centre of the image loses very little quality. Im not using a 682mm lens to shoot landscapes so Im really only interested in the centre of the image anyway.

 Aussie Coop's gear list:Aussie Coop's gear list
Canon PowerShot S100 Canon EOS 5D Mark III Canon EOS M Canon EOS M6 Canon EOS R +12 more
nnowak Veteran Member • Posts: 7,396
Re: Speed Booster Sigma 150-600mm

Aussie Coop wrote:

nnowak wrote:

Aussie Coop wrote:

Has anyone used the Sigma 150-600 Contemporary on an Eos M with the Viltrox 0.71 Speed booster ?

I read there was a vignette and Im trying to find out how much and what people thought?

The M6 is a secondary camera and Im usually using the Sigma on my EosR but was thinking the boost in light would come in handy.

Puting a speedbooster on the Sigma 150-600mm f/5-6.3 creates a 106-426mm f/3.5-4.5 lens. When you mount this combo on an M series camera it is equivalent to 170-682mm f/5.6-7.1 on full frame. You are basically right back where you started with this lens on your R, but with the additional image degradation caused by the speedbooster.

Im aware of the new focal length, but how do you come at it being f/7.1 , doesnt the booster increase light by at least 1 stop?

Yes, it does, but based on sensor area, your M6 is 1.33 stops behind your full frame R for noise levels.

So that would make it 682mm f/4.5 at the long end by my calculation ( far from being where it is on the R )..

You are only calculating half of the equivalence based on the crop factor.

The speedbooster makes your Sigma a 426mm f/4.5 lens on the long end. That part is irrespective of the camera you mount the combo on (you could mount the same combo on a m4/3 body)

426mm f/4.5 on Canon crop is equal to 682mm f/7.1 on full frame

From what Ive read the centre of the image loses very little quality. Im not using a 682mm lens to shoot landscapes so Im really only interested in the centre of the image anyway.

A speedbooster is the exact opposite of a teleconverter. A teleconverter takes only the central portion of a lens and magnifies it to cover the entire frame. The speedbooster takes the entire image circle of a full frame lens and compresses it to only cover a crop sensor. If you have a full frame lens with soft corners, those soft corners will be even more apparent with the speedbooster attached.

DPReview wrote a comprehensive article explaining equivalence a few years ago....

https://www.dpreview.com/articles/2666934640/what-is-equivalence-and-why-should-i-care

If you want the short version, mounting your Sigma on the M6 with a speedbooster has zero advantage over using the same lens on your R, and several disadvantages.

rmexpress22 Senior Member • Posts: 1,768
Re: Speed Booster Sigma 150-600mm
3

Aussie Coop wrote:

Im aware of the new focal length, but how do you come at it being f/7.1 , doesnt the booster increase light by at least 1 stop? So that would make it 682mm f/4.5 at the long end by my calculation ( far from being where it is on the R ). From what Ive read the centre of the image loses very little quality. Im not using a 682mm lens to shoot landscapes so Im really only interested in the centre of the image anyway.

A crop body is like a magic wand. It magically changes the dimensions of your lens and the physical aperture becomes smaller.

Kidding.

An aperture of f/4.5 is the same on full frame, crop, or on a potato. The FOV changes, as you know. The light that passes through the lens is the same.

 rmexpress22's gear list:rmexpress22's gear list
Canon EOS 5D Mark IV Canon EOS M6 Canon EF-M 22mm f/2 STM Sigma 85mm F1.4 Art Canon PowerShot G16 +19 more
nnowak Veteran Member • Posts: 7,396
Re: Speed Booster Sigma 150-600mm
2

rmexpress22 wrote:

Aussie Coop wrote:

Im aware of the new focal length, but how do you come at it being f/7.1 , doesnt the booster increase light by at least 1 stop? So that would make it 682mm f/4.5 at the long end by my calculation ( far from being where it is on the R ). From what Ive read the centre of the image loses very little quality. Im not using a 682mm lens to shoot landscapes so Im really only interested in the centre of the image anyway.

A crop body is like a magic wand. It magically changes the dimensions of your lens and the physical aperture becomes smaller.

Kidding.

An aperture of f/4.5 is the same on full frame, crop, or on a potato. The FOV changes, as you know. The light that passes through the lens is the same.

Adding a speedbooster does not magically allow a crop sensor to capture more light than that same lens on a full frame camera.  By your logic, my smartphone with its f/1.8 lens will produce the same image quality as f/1.8 on full frame.

Just because apertures are the same and you can use the same exposure settings does not make the actual images the same. Shooting at ISO 100, 1/100, and f/1.8 will produce different images depending on sensor size. Not only will the Depth of Field (DoF) be different, but noise levels will be different too.

The following two setups will produce an image with the same Field of View (FoV), same DoF, same level of motion blur, and the same noise levels. Basically, the same image in all regards

  • On Canon Crop - 426mm, f/4.5, 1/100, and ISO 100
  • On Canon Full Frame - 682mm, f/7.1, 1/100, and ISO 250
rmexpress22 Senior Member • Posts: 1,768
Re: Speed Booster Sigma 150-600mm
4

The 5Ds and 80D have almost the same pixel pitch. You can just about fit the 80D sensor inside the 5Ds 1.6x center.

So you're saying that 1.6x crop in the 5Ds absorbs less light than the pixels outside of the 1.6x crop? And then, if you crop the 5Ds in post to 20mp, that's suddenly a different aperture?

FF shooters really obsess about doing these odd conversions. You don't see medium format shooters going around telling FF shooter that their f/2.8 lenses are a smaller aperture.

Aperture is a physical ratio. You can say FOV, DoF, and light gathering is different, but the aperture is the same.

 rmexpress22's gear list:rmexpress22's gear list
Canon EOS 5D Mark IV Canon EOS M6 Canon EF-M 22mm f/2 STM Sigma 85mm F1.4 Art Canon PowerShot G16 +19 more
Sittatunga Senior Member • Posts: 3,029
Re: Speed Booster Sigma 150-600mm
1

rmexpress22 wrote:

The 5Ds and 80D have almost the same pixel pitch. You can just about fit the 80D sensor inside the 5Ds 1.6x center.

So you're saying that 1.6x crop in the 5Ds absorbs less light than the pixels outside of the 1.6x crop? And then, if you crop the 5Ds in post to 20mp, that's suddenly a different aperture?

FF shooters really obsess about doing these odd conversions. You don't see medium format shooters going around telling FF shooter that their f/2.8 lenses are a smaller aperture.

Aperture is a physical ratio. You can say FOV, DoF, and light gathering is different, but the aperture is the same.

You're arguing focal reducers with someone who was cobbling EF-M reducers together before they were commercially available. I know who I believe.

Yes, focal reducers increase the f/number, but it's still the same size aperture in mm. Photons will pass through it at the same rate whether you concentrate them with a focal reducer or spread them out with a teleconverter.  It's the number of photons captured that gives you information, not how far they are spread out.

If you have a full-frame camera, turning up the ISO will increase your shutter speed more effectively with less image quality loss than using that same lens on an APS-C camera with a focal reducer.

nnowak Veteran Member • Posts: 7,396
Re: Speed Booster Sigma 150-600mm
1

rmexpress22 wrote:

The 5Ds and 80D have almost the same pixel pitch. You can just about fit the 80D sensor inside the 5Ds 1.6x center.

So you're saying that 1.6x crop in the 5Ds absorbs less light than the pixels outside of the 1.6x crop? And then, if you crop the 5Ds in post to 20mp, that's suddenly a different aperture?

That is not at all what I have written

FF shooters really obsess about doing these odd conversions. You don't see medium format shooters going around telling FF shooter that their f/2.8 lenses are a smaller aperture.

Aperture is a physical ratio. You can say FOV, DoF, and light gathering is different, but the aperture is the same.

Does f/1.8 on a smartphone produce the same image as f/1.8 on full frame? Stop focusing on physical aperture size. Aperture is just one of the ingredients in creating an actual image. Shutter speed and ISO matter too. The part you seem to be missing is that noise levels at a given ISO vary depending on sensor size. ISO 100 on the OP's M6 does not look the same as ISO 100 on the OP's R. Equivalence accounts for these sensor size differences. Using f/4.5 and ISO 100 on the M6 will look the same as f/7.1 and ISO 250 on the R. Not only will depth of field be the same, but noise levels will be the same too.

If you still can't understand the concept of equivalence, please read this excellent explanation from DPReview.

https://www.dpreview.com/articles/2666934640/what-is-equivalence-and-why-should-i-care

Aussie Coop
OP Aussie Coop Regular Member • Posts: 398
Re: Speed Booster Sigma 150-600mm

I appreciate the responses, my whole point originally was to lower the ISO in low light situations, which doesn't seem to be what would actually happen in terms of a direct noise comparison with the R

Thank you

 Aussie Coop's gear list:Aussie Coop's gear list
Canon PowerShot S100 Canon EOS 5D Mark III Canon EOS M Canon EOS M6 Canon EOS R +12 more
nnowak Veteran Member • Posts: 7,396
Re: Speed Booster Sigma 150-600mm
1

Aussie Coop wrote:

I appreciate the responses, my whole point originally was to lower the ISO in low light situations, which doesn't seem to be what would actually happen in terms of a direct noise comparison with the R

Exactly!  Your not the first person to ask tqqhis type of question before.  The whole speedbooster concept can get a bit confusing when you start multiplying multiple crop factors together.

In simplest terms, a speedbooster takes a full frame lens and turns it into a crop lens.  This "new" crop lens will produce an image very similar to what that full frame lens would produce on full frame.  Under no circumstances will a speedbooster allow a full frame lens to produce a better image on a crop sensor than the naked lens would produce on a full frame camera.

Thank you

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