Background Blur/Bokeh for portraiture

[Deucalion]

I'm relatively new to photography... and I admit that I have yet to master all the bells and whistles of my camera (it was a gift after all) if a newbie to photography is someone on the ground floor, I would describe myself as probably still standing outside the building. and I REALLY want to be INSIDE that building!

so please bear with me my question is actually two parts.... I think , I've always wanted to try a "portrait shot" the kind that has the subject in focus and having the background blurred enough that your eyes are immediately drawn to the subject. (did i get that right? sorry English isn't really my first language)

after reading the tutorials, (some of it still sounds Greek to me, I hope to understand some of it after I read it again.... and while I continue to fiddle and get familiar with the settings of my camera.. hopefully...eventually.. ) I find that there is a range/focal length (?) in the type of lenses used for "portraits" and that the lens I use apparently doesn't fall into that category (17-55) but I also read that you can use different lenses to achieve the same kind of thing like using a telephoto lens for landscapes as opposed to wide angle lenses.

so my question would be, could I get a "portrait shot" out of my lens that includes that nice "background blur?" and the second is why is the range of 70+ in lenses considered as "portrait" territory? I've been reading that the 80 range/length (?) is the correct (?) range to use when doing portrait pictures. Does that mean that I should only shoot at my lens' maximum length of 55mm (w/c translates to 80 something on my 60D?) to get my desired effect?

many thanks in advance! for those who care to teach this wonderful skill/art to me, still standing outside and in awe of that building

[Sponge]

Hi Reginald, I'm sure you'll get some great advice from some of the more qualified on here but I'll try to help with what I can.

What's considered to be a good focal length for portraits is roughly between 85mm and 100mm. This is because longer focal lengths start to compress an image which can give flattering results for portrait photography but too much compression (too long a focal length) starts to diminish this benefit. However, some say that a wide-angle lens has it's benefits when taking portraits of children. One being that having to be so close can get playful reactions from them and another being that the expanding effect of wide-angle lens, can make children's faces playfully disproportionate with the rest of their body.

As far as bokeh goes, it's fairly important that your lens has a low F-number (wide-aperture), the lower the better. A longer focal length helps too as well as distance between subject and background. For portraits you'd want to mostly fill the frame with your subject and have a background around 5m behind the subject (as a starting point) and use as low a F-number as you can with a portrait focal length. In your case you'd want to use your lens at it's longest focal length and if the aperture is still very wide at that length (low F-number), even better.

Cheers,
Patrick

[Dave Humphries]

Hi Reginald,

Your understanding of the principles of focal length is basically correct from what you say, the bit that was missing was the importance of using a wide aperture and having a good ratio camera to subject and subject to background distances.

Patrick's advice is pretty good, to use your current 17-55mm kit lens, shoot in Aperture Priority mode (Av) and select f/5.6. If you choose wider than that, say f/3.5 (while at 17mm), you will probably notice that when you zoom in, this changes to f/5.6.

So the next thing you can do to help is to keep the subject well away from the background, 5m might be difficult to achieve, but if you can, do so, failing that just get that distance as big as possible. I usually do a quick visual check that the distance behind the subject is at least twice the distance between me and the subject.

What we have covered here are two small aspects of shooting portraits, there is much else to learn to get inside this particular building

If you haven't already, I thoroughly recommend you have a read of Colin's excellent series on the subject, available here.
School of Portraiture - Links to Lessons 1 through 8

PS I amended the thread title slightly as this is quite specific

Good luck,

[DanK]

If my understanding is right, you are correct that you need to correct the focal length range that Patrick notes to adjust for the fact that you are shooting a crop. Those were the classic portrait lengths for 35mm film cameras. With those cameras, those focal lengths put you a distance from the subject that provides a particularly pleasing perspective. On a crop,a lens with those lengths divided by 1.6 should place you at a similar distance. I am certainly not an expert portrait photographer, but I shoot most people shots (with a 50D) between 45 and 75 mm.

I no longer have the URL, but there is a page posted that has identical portraits shot at a large number of focal lengths. what is striking is that the effects of going somewhat longer than the classic lengths seemed pretty minor to me.

It was not clear to me whether you are using the 17-55 f/2.8 or the 18-55 kit lens. If you are using the 2.8, you should be able to get considerable blur at 2.8 if the background is not too close. I will post one I took with a crop sensor (50D) at 68mm and f/2.8. It was shot with a flash aimed slightly back over my left shoulder, with a Demb Flip-It projecting light forward for catch light. If you are using the kit lens, I suspect you will find the DOF at 55 mm wide enough to be disappointing unless you put the background quite far back.

[rpcrowe]

I personally prefer a slightly longer than traditional focal length for head and shoulder portraiture. I have recently surveyed a selection of my portraits (I usually shoot portraits with my 70-200mm f/4L IS lens) and determined that I generally shoot somewhere between 130 and 140mm on a 1.6x crop camera. However, that just happens to be the focal lengths I like the best at the distances I usually shoot. I select the focal length and lens to subject distance by what "looks good to me". I most often set my aperture at f/4 which will give a nice background blur when shooting at that relatively long focal length. Espeially if my subject is a fair distance away from the BG.

Many "home portrait" attempts have problems, IMO, because the photographer is shooting in a "normal size" room and doesn't have the space to situate the subject a goodly distance from the BG.

If I were shooting with the 17-55, I would most likely be shooting at the longest focal length available. I would need to play with head and shoulders portraits at this focal length to see whether f/2.8 or f/4 would give me the best look.

After-all, portrait photography is an art. Sure there is some science involved but, my focal length choices are based on "what looks good".

Some photographers espouse the use of extremely wide apertures such as f/1.4 or even f/1.2 for portrait photography. Their rationale is that the wider aperture will prvide a slimmer DOF. It certainly does, but must often the results have a DOF that is too narrow for my likes. I absolutely hate a DOF that has one eye in focus with the other eye OOF. However, I don't mind the eyes and nose being in sharp focus with the ear or ears being a bit OOF.



Whether you need to knock your BG totally OOF depends on the background. Often a canvas BG can be left in focus a bit more than a muslin BG. The muslin BG will sometimes look like an unmade bedsheet due to wrinkles and creases. Those really need to be OOF not to draw attention away from the subject. Outdoors, especially with foliage as a BG, I like to blur it as much as possible. This can be done even with the relatively small f/4 aperture of my 70-200mm f/4L IS lens; especially if I am relatively close to my subject in comparison to the distance behind to the BG. Here is an example of background blur that I can achieve even with the f/4 aperture if I am shooting at a long focal length and the BG is a distance behind my subject...



BTW: The really smooth bokeh in this image is partially due to the rounded aperture blades in the 70-200mm f/4L IS lens. The 70-200mm f/2.8L IS ii lens also incorporates the rounded aperture blades.

[Deucalion]

thanks for your explanation Patrick! always wondered why that 80+ focal length was considered the sweet spot for portraits, I didnt realize that having the background near/far from the subject makes a difference, always thought that I could get that nice blur, the background wouldnt matter. didn't think to consider that even if blurred it could actually still redirect one's attention to it rather than the subject.

Thanks Dave! truth be told, I actually stumbled upon Colin's portrait academy series after I posted my question, and I truly plan to read it this weekend so I can gain more knowledge about photography and portrait work, I enjoy reading thru the threads of this site as you can really learn a lot from the explanations and discussions on various subjects. and I don't just plan on getting inside that building I plan to scale it to the very top

Dan thats a really nice photograph, and you say that it was from a crop camera at 66mm? then there is hope for me and my 17-55mm lens, and yes I am using and EF-S 17-55 2.8 lens, or should I say its the only lens I actually own. how far were you when you took that picture?

Richard those are really nice photos, I kind of like the one with dog than the first one but that's just me, I asked the question for this thread because I only own one lens and that is the 17-55mm F2.8, having traded my kit lens which was actually longer the EF-S 18-135mm, I kind of had that face palm moment when I read somewhere that the when taking portraits the focal length of 80+mm is ideal/sweet spot and I had already traded my longer kit it for the 17-55mm. I'm still trying to master my current equipment, I'd like to ask tho, could that second shot (dog) be achieved using the same lens/focal length of 17-55mm?

[timmy]

I had some good results from my kit lens, but i did have to make sure the was enough room from the back ground to my subject. i then purchased a cheep tamron 70-300 lens for apron £140.00 this gave me some fantastic results as the lens was soft, down side the lens wasn't overly sharp. it did give me what i wanted at the time though. i now use either a nikon 50mm prime or my 70-300 nikon for portraits. Some great advice from everyone here and you will find the DOF that you like and you will get some great results with your 17-55 (use at the 55mm) give your self distance and play with the F factor. enjoy and play.

[Sponge]

thanks for your explanation Patrick! always wondered why that 80+ focal length was considered the sweet spot for portraits, I didnt realize that having the background near/far from the subject makes a difference, always thought that I could get that nice blur, the background wouldnt matter. didn't think to consider that even if blurred it could actually still redirect one's attention to it rather than the subject.

Distance from lens to subject and subject to background does make a difference but just to be clear, my example of 5m is just a general figure. With a very wide aperture and a big sensor you can get away with a lot less if the subject is relatively close.

Your lens should get you some decent results since you're able to use F 2.8 at the long end. The only thing to keep in mind is that most lenses are sharpest when stopped down a little bit (in your case around F 5.6 should be the sweet spot) so you'll have to decide between minimum depth of field (maximum background blur) and maximum sharpness. This difference in sharpness varies between lenses so depending on your demands it may not be enough to worry about.

[timmy]

Distance from lens to subject and subject to background does make a difference but just to be clear, my example of 5m is just a general figure. With a very wide aperture and a big sensor you can get away with a lot less if the subject is relatively close.

Your lens should get you some decent results since you're able to use F 2.8 at the long end. The only thing to keep in mind is that most lenses are sharpest when stopped down a little bit (in your case around F 5.6 should be the sweet spot) so you'll have to decide between minimum depth of field (maximum background blur) and maximum sharpness. This difference in sharpness varies between lenses so depending on your demands it may not be enough to worry about.

i generally find f8 is the sharpest for most lenses at a rule, but not a great bokeh, i say play with the variants with your lens and decide what you think is best. then remember those settings and use when you want... just play and learn.

[Sponge]

i generally find f8 is the sharpest for most lenses at a rule, but not a great bokeh, i say play with the variants with your lens and decide what you think is best. then remember those settings and use when you want... just play and learn.

I've always heard that generally, 2 full stops smaller than wide open is usually a lens' sharpest aperture and have found that to be true with my lenses. My Canon FD 1.4 is sharper at F2.8 and F4 than at F8 but certainly my slower lenses are about as sharp as can be at F8. I agree that Reginald should experiment but I think he's on here seeking advice for a reason.

[William W]

so my question would be, could I get a "portrait shot" out of my lens [assumed EF-S 17 to 55F/2.8 IS USM] that includes that nice "background blur?"

Yes.

***

The second is why is the range of 70+ in lenses considered as "portrait" territory?

The Focal Length range from about 85mm to about 135mm, refers to use on a 135 Format Camera (AKA “Full Frame”).

The reason why this range of Focal Length is considered desirable is because of the typical SD (Shooting Distance) used for Portraits when these Focal Lengths are used.

SD determines PERSPECTIVE.

And the Shooting Distances when using an 85mm to 135mm lens for a Portrait make a ‘flattering’ perspective of (especially) the Face, relative to the other body parts.

***

I've been reading that the 80 range/length (?) is the correct (?) range to use when doing portrait pictures.

No - it is not ‘correct’ to only use that range of Focal Lengths for Portraits.

Yes – that range of Focal Lengths is ‘often used’

Portraits can be made with lenses of many different Focal Lengths.

***

Does that mean that I should only shoot at my lens' maximum length of 55mm (w/c translates to 80 something on my 60D?) to get my desired effect? [assumed that the ‘desired effect’ is background blur]

No.

You can get Background Blur for a Portrait when using a wide angle lens (e.g. at about 20mm for your camera) and also you can get Background Blur using a Standard lens (about 30mm for your camera) and also you can get background blur using a lens longer than a 55mm with your camera.

Depending upon the shot, you do not necessarily need an aperture of F/2.8 or larger, either.

You should experiment.

There are many valuable tips already on this thread for your experimentation.

SAMPLE of Background Blur using (not your lens) but the 18 to 55 "Kit Lens".
The EXIF is attached FYI:


If you cannot read the EXIF, the extract is here:

Exposure Date: 2012:06:21 08:32:48;
Make: Canon;
Model: Canon EOS 20D;
ExposureTime: 1/250 s;
FNumber: f/5;
ISOSpeedRatings: 400;
ExposureProgram: Manual;
ExposureBiasValue: 0;
MeteringMode: Average;
Flash: Flash did not fire, compulsory flash mode;
FocalLength: 37 mm;
Software: Adobe Photoshop CS2 Windows;




WW

[jcuknz]

As a P&S or bridge camera worker, but with a good editing programme, I have never bothered about in-camera selective blurr becuase I know in 95% or more cases I will achieve the desired blurr in PP so it doesn't matter what aperture I work. usually, about f/5.6. Mentioned hopefully get across the message that there are more than one way of skinning the rabbit as the saying goes. Just as there can be problems with in-camera, likewise there are photos where PP doesn't work. Untidy straggly hair is one which comes to mind and also less so that beautiful dog above of Richard's.