# Sigma 50 1.4 or canon 85 1.8



## Frage (Dec 21, 2012)

Hi,

I would like to know your thoughts on aquiring a new lens for my 600d.
With the lens I would like to do some low light and strob photos, also but not that much street. It should be also useful for video (manual focus capability).
I would like to have some nice sharp images and a nice oof background. What would you recomend?
I also considered the Samyang 85mm 1.4 but I really do not know how is it to focus on a 600d with the stock focus screening, which I am not willing to replace. 
I know 50 and 85 are quite different focal lenghts and actually I already have the sigma 17 50, which makes me quite happy, but sometime the f 2,8 does not deliver the oof I wish.

Thank you for your advices.


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## RS2021 (Dec 21, 2012)

Frage said:


> Hi,
> 
> I would like to know your thoughts on aquiring a new lens for my 600d.
> With the lens I would like to do some low light and strob photos, also but not that much street. It should be also useful for video (manual focus capability).
> ...



On a full frame the focal lengths are different animals. But on a crop such as yours they are more alike (excluding the brand name and IQ and sticking just to focal length) in that they will both fit the portrait genre. They will fall on the lower and higher end of the "medium" tele lenses on a crop sensor. So depends on if that is what you intend them for. Indoors they both will be a tight fit on a crop sensor for groups of people. Head shots they are perfectly suited for. The 85mm on crop would be similar to 135mm on FF so outdoor portraits etc are doable and perhaps some ambient light sports too.


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## Nishi Drew (Dec 21, 2012)

For video use it'll even be tighter with the 16x9 aspect ratio effectively cropping the image and making the lens feel even tighter. 50mm on crop worked well for video use for me, but only a tripod, for handheld/general stuff it's rather long, a fast wide angle would better for overall use, the Samyang 35mm or 24mm are great options too if manual focus is good. But again for portraits, a 50mm works well enough


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## jhanken (Dec 21, 2012)

Its interesting, I actually own both lenses, and I like them both for different reasons. My camera is a 5D classic, I have the same issues focusing my non-auto focus lenses from time to time, particularly in low light where a fast lens is needed.

Putting on my Captain Obvious hat here, and the difference in focal lengths notwithstanding, the 1.4 aperture of the Sigma lets in about 62% more light (more than half an f-stop), and that can be signficant if you are trying to get crisp low light shots. On a crop body, the 50 would be more of a natural focal length for portraits.

I absolutely love my Sigma 50. Love, love, love it. 

Had to shrink these files a bit to upload them, but you should get the idea.


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## jhanken (Dec 21, 2012)

Another.


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## Frage (Dec 22, 2012)

Thanks for your answers and photos.
I would like to know your opinions about how the oof areas behave in the case of the 50 1.4 due to the big apperture and in the case of the 85 1.8 due to its focal lenght (background compresion).
Which lens delivers the more blurred background and the better bokeh?

Saludos


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## helpful (Dec 22, 2012)

The Canon 85mm 1.8 delivers better out of focus backgrounds and nicer bokeh, with much more blur.

At fixed, non-macro distances, depth of field is approximately inversely proportional to the square of the focal length, while it is directly proportional only to the first power of the f-number.

So the 85mm lens gives approximately 2.89 times more blur at equivalent f-numbers.


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## lexar (Dec 22, 2012)

I think 50 is too long on a crop for general use.

I got the Sigma 30 f1.4 and love it on my t2i!


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## elflord (Dec 22, 2012)

Frage said:


> Thanks for your answers and photos.
> I would like to know your opinions about how the oof areas behave in the case of the 50 1.4 due to the big apperture and in the case of the 85 1.8 due to its focal lenght (background compresion).
> Which lens delivers the more blurred background and the better bokeh?
> 
> Saludos



To your first question, if you're shooting the same composition, the longer lens (85mm f/1.8) will provide a more blurred background but require more working distance. 

If you shoot close to minimum focus distance (that is, if you're somewhat distance constrained) you can get shallowed dof with the 50mm f/1.4 because if focuses much closer. 

I don't think anyone can answer your second question (which has "better" bokeh) for you unless they own both lenses. I would imagine owners of both lenses would be quite happy with the bokeh so most respondents will recommend the lens they own. I don't own either of them, I own the Sigma 85mm f/1.4 and the Canon 50mm f/1.4. For my purposes, I found the shorter focal length more useful on APS-C.


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## elflord (Dec 22, 2012)

privatebydesign said:


> elflord said:
> 
> 
> > To your first question, if you're shooting the same composition, the longer lens (85mm f/1.8) will provide a more blurred background but require more working distance.
> ...



Blur disc diameter depends on (is directly proportional to) absolute aperture size. btw, depth of field is also smaller (at the same shooting distance) with the longer lens. 

The tendency of background objects to take up a larger fov with the longer lens does make for simpler smoother backgrounds which is why longer lenses are considered so effective at "blowing away" the background. 

Having objects in the background less recognizable because they appear smaller doesn't help you much -- because it also means on the flip side that there are more such distant objects in the frame making for a potentially busier background. 

In practice both lenses will do an excellent job at blurring the background but if your goal is to go for an isolation effect, the longer lens will do a better job.


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## verysimplejason (Dec 22, 2012)

For portrait work on APS-C, I'd choose the 85mm F1.8. I don't trust third party brands that much.


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## KurtStevens (Dec 22, 2012)

Had the sigma 50 1.4 and compared to the canon 85 1.8 (i have one looking to sell too), the canon is hands out the winner. on apc-c is going to be a bit tight, 135, but still amazing lens. that and the canon 50 1.4 are the best lenses you can buy for their money. trust me i'm almost like a doctor almost.


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## drmikeinpdx (Dec 22, 2012)

I have them both. The Canon 85 1.8 focuses a bit more accurately and consistently than the Sigma 50, but they both create nice bokeh wide open. The choice would really depend on the exact kind of photos you are doing.

If I have limited space to work and a need to blur the background, I use the Sigma 50. The Canon 85 is nice when I am working a bit father back from my subject. I do notice that the 85 needs a higher shutter speed or else I have to use a tripod to avoid motion blur. I'm using them on a 5D3, which makes them both focus much better than my 5D classic.

The Sigma looks more impressive if you are trying to impress your photographer friends. 

The first photo is with the 85mm at 1/320th, f/2.8, ISO 12,500 under a bridge on a cloudy day.







The second photo is with the Sigma 50 at f/1.4 in a backlit situation. Sorry the two photos weren't taken under similar conditions.


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## elflord (Dec 22, 2012)

privatebydesign said:


> Again you are incorrect, or we are talking about the same thing in a different way, the disk will be bigger, but the background object as a percentage will not be as blurred.



I think we agree on the analysis , but we see things differently. I don't care how blurred the background object is _as a percentage of its projection onto the sensor_, I care how much blurring there is relative to the size of the sensor (e.g. the effective "smoothing kernel size" with respect to the sensor size). Because that's what determines how "smooth" the background looks. 

I completely agree with the rest of your analysis (the part I snipped).


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## dtaylor (Dec 23, 2012)

I like both, but I find myself using the Sigma much more often. The focal length just seems more useful on crop.

85mm will result in more blur, but quality of blur (bokeh) has to go to the Sigma by a hair. That lens really has unique and creamy bokeh.

Agreed that the 85 is a bit more consistent in AF.


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## Frage (Dec 23, 2012)

So, thank you so much for your answers and very instructive discussion. I didn´t expected to induce sucha a technical debate. ;D
I ordered the Canon 85mm 1.8 and I will give it a try. Even if I am a bit sceptical about the CA´s.

The Bokeh of the sigma looks nice, but since it is a bit of an investment and I already have the sigma 17 50 2.8 I would like to try another focal length.

Saludos.


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