Handheld telephoto.

[sk66]

I suspect someone would even know the formula allowing you to calculate the exact comparisons.

I can SWAG the DOF with a formula, but not the blur radius nor how OOF the areas not w/in the DOF will appear...

But none of these things actually have much to do with "bokeh"... that is a characteristic of a particular lens (much like sharpness is).

You're mixing terms, "bokeh" refers to the amount of blur in the background

Actually it doesn't refer to the amount of blur. It refers to how blurred points are rendered.

 

[mark.roper]

Actually it doesn't refer to the amount of blur. It refers to how blurred points are rendered.

Fair enough, but either way, if the OP is concerned with bokeh, then a good wide prime seems a better bet than the 70-200 f/2.8 (IMHO).

 

[sk66]

Fair enough, but either way, if the OP is concerned with bokeh, then a good wide prime seems a better bet than the 70-200 f/2.8 (IMHO).

Only if the goal is shallow DOF...

To illustrate, this image was taken with a 400/2.8 +1.5TC (550mm) set at f/11... there is absolutely no detail left in the BG and yet this lens/combination actually has pretty marginal bokeh characteristics.

RTHU by Steven Kersting, on Flickr

Edit: If this same image had been taken with a shorter lens set at a wider aperture it would have even less DOF... that would affect the subject but it would not really affect the BG (you can't get much more OOF than it already is).

 

[HoppyUK]

Good background blur simulator here (and depth-of-field calculator). Well worth a try
https://dofsimulator.net/en/

Rule of thumb for background blur/bokeh is doubling the focal length (and moving back to twice the distance) blurs the background the same as dropping the f/number two stops. Eg, 50mm f/2 lens for a portrait at 1m has same amount of background blur as 100mm f/4 lens at 2m*

In other words, for bokeh lovers, it's often easier and better to simply step back and zoom in.

*the two images will look very similar with same framing of the main subject, but perspective will be different (because of the greater shooting distance); DoF on the main subject will be increased at f/4; and the background will be enlarged.

 

[HoppyUK]

I can SWAG the DOF with a formula, but not the blur radius nor how OOF the areas not w/in the DOF will appear...

But none of these things actually have much to do with "bokeh"... that is a characteristic of a particular lens (much like sharpness is).

Actually it doesn't refer to the amount of blur. It refers to how blurred points are rendered.

I know what you're saying Steven, but that isn't what most people understand by bokeh - they simply mean the amount of blur.

 

[sk66]

Good background blur simulator here (and depth-of-field calculator). Well worth a try

I don't like that one... the BG is always at a fixed distance, and why isn't the subject ever in focus?

This site is better IMO as it shows blur over distance, and it is the BG distance vs DOF that really matters the most in terms of blur... although it is not a visual simulation (unfortunately).

This shows three situations, all with the same portrait composition. Note that the 100/2 has ~ the same DOF as the 50/2 situation, and the 100/4 has ~ 2x the DOF (SWAG).

but that isn't what most people understand by bokeh -they simply mean the amount of blur

I know... and it's something of a pet peeve for me. That's because even the chart above (and especially the simulator) doesn't tell the whole story where bokeh characteristics are of concern. In the scenario above, if the 100/2 lens has bad bokeh characteristics it would likely look worse (sharper/busier/etc) in all of the situations where the BG/FG is even marginally near the DOF... even though it will have an ≥ amount of blur.

 

[Lensflare]

AndyG123
When you are shooting with the longer focal lengths - your technique needs to be not just in selection of settings, but your body position needs to be optimal too. Rifle shooting teaches very similar techniques - your elbows need to be tucked into your ribs - HARD, use your skeletal form as support, not the jelly we call muscle (which is 85% water and not at all rigid, even toned muscle is like jelly). Your lens hand needs to be under the lens, not over the top. Wrist cocked to create a firm support, elbow in tight, into your ribs or better still your pelvic bone - your feet position also play a part. You will also create camera shake through your breathing and in extremis your heart beat can create it.

I know there is going to be a backlash saying this is all b****x, but it isn't - I used to work at the World Superbikes and Grand Prix, hand holding a 300 f2.8 down to 1/30th and the 500 f4 down to 1/60th - and no, I didn't own a monopod, I tried one, hateful things. They prevent you from swinging naturally and smoothly - oh and back in those days we had to follow focus during the exposure too, working with a film speed as high as 100 sometimes but mostly with ISO 12 equivalent (Fuji Velvia 50, polarised). So, while the camera settings are one aspect of telephoto technique, so too are these others.

 

[sphexx]

I know what you're saying Steven, but that isn't what most people understand by bokeh - they simply mean the amount of blur.

That’s true unfortunately but should still be corrected since there is no other word in English whereas we have ‘blur’ for blur .

 

[HoppyUK]

That’s true unfortunately but should still be corrected since there is no other word in English whereas we have ‘blur’ for blur .

The problem is that bokeh has no direct translation, but through use it has come to mean the amount of blur for most people - the quantity rather than the quality of it. So that's how I use it. YMMV

That might upset the purists, but then when you attempt to define the quality of bokeh we run into terms like creamy and soft and smooth (considered good), and busy and swirly with onion rings and cats eyes etc etc (considered bad, though sometimes good. Apparently). I don't find those terms any more helpful.

 

[sphexx]

The problem is that bokeh has no direct translation,

I don’t get this, it is a borrowed word from Japanese and was well described when first written about in photo journals.

but through use it has come to mean the amount of blur for most people - the quantity rather than the quality of it. So that's how I use it. YMMV

That might upset the purists, but then when you attempt to define the quality of bokeh we run into terms like creamy and soft and smooth (considered good), and busy and swirly with onion rings and cats eyes etc etc (considered bad, though sometimes good. Apparently). I don't find those terms any more helpful.

I understand your general point but it’s a loss of information if you just use it to mean blur which is a perfectly good word (and shorter ) which everyone can understand so why use bokeh for that?

 

[HoppyUK]

I don’t get this, it is a borrowed word from Japanese and was well described when first written about in photo journals.

Yes, I've read plenty of those fine articles but they're neither definitive nor particularly helpful IMHO. 'Bokeh' has no direct translation and the best I've come across is simply 'fuzzy' which is a) probably as good as it gets, and b) suitably vague in English and can be applied to different things in different ways - like bokeh in Japanese.

I understand your general point but it’s a loss of information if you just use it to mean blur which is a perfectly good word (and shorter ) which everyone can understand so why use bokeh for that?

If you want to just say blur that's fine by me, but bokeh has come to mean specifically background blur (and bokeh is shorter ) that's been deliberately put way out of focus. It's just a shorthand, and if further comment is needed then you'll need to use a lot more words anyway because even the pedants can't agree on what actually constitutes good or bad bokeh. It's very much a subjective and personal thing, and also varies according to the type of image.

 

[sk66]

but bokeh has come to mean specifically background blur (and bokeh is shorter ) that's been deliberately put way out of focus.

Yes, and in that context it is completely irrelevant as a lens quality... I can blur the crap out of the BG at any aperture setting with any lens on the market in the right situation. And it results in people buying super wide aperture lenses and running around photographing things with stupid thin DOF because they don't know any better.

FWIW, I don't care much about bokeh qualities and stupid thin DOF is fine when it serves a specific purpose. But bokeh is a specific quality of an individual lens; exactly like sharpness is (but opposite).
And one can argue as to whether a lens is sharp enough/too sharp just as one can debate bokeh qualities. But that doesn't negate it being a specific characteristic of a particular lens.

If popular understanding/belief is automatically "right," then I'm screwed (I live in the land of Trump).

 

[sphexx]

Yes, and in that context it is completely irrelevant as a lens quality... I can blur the crap out of the BG at any aperture setting with any lens on the market in the right situation. And it results in people buying super wide aperture lenses and running around photographing things with stupid thin DOF because they don't know any better.

I think the attraction of stupid thin DOF is that for many it’s a substitute for composition.

If popular understanding/belief is automatically "right," then I'm screwed (I live in the land of Trump).

Sadly, we all live in the world of Trump. Though looking on the bright side, since we are considering the meanings of words, here in the UK trump=fart

 

[chris malcolm]

AndyG123
When you are shooting with the longer focal lengths - your technique needs to be not just in selection of settings, but your body position needs to be optimal too. Rifle shooting teaches very similar techniques - your elbows need to be tucked into your ribs - HARD, use your skeletal form as support, not the jelly we call muscle (which is 85% water and not at all rigid, even toned muscle is like jelly). Your lens hand needs to be under the lens, not over the top. Wrist cocked to create a firm support, elbow in tight, into your ribs or better still your pelvic bone - your feet position also play a part. You will also create camera shake through your breathing and in extremis your heart beat can create it.

I once had to time an exposure in between pulse beats to get it sharp.

I was in a cathedral which permitted photography but forbade tripods, trying to photograph a distant high mosaic in dim light. Luckily parts of my tripod could also be assembled into a monopod. I didn't want to discover whether the local Sicilian monks considered their ban of tripods also included monopods, so I secreted myself in the middle of a pew with people seated nearby all around. I knew I'd want to do a lot of shadow lifting in the shaded parts of the image, so I wanted the lowest ISO I could get, i.e. the longest exposure.

I tried clamping the monopod to the back of the pew with a strong hand grip. That made it very steady but I could see the regular ticking of my pulse in the magnified image. So I had to take the shot by timing the exposure to be inside the steady period between pulse beats, releasing the shutter with a radio remote to avoid shutter button shake. I reckoned 1/3 second exposure was the longest I had a fair chance of fitting into the steady period between pulses. On my 18-250mm zoom at 100mm that gave me f5.6 and ISO 160. It worked! The trickiest long exposure telephoto shot I've ever had to do!

The sharpest shot of the Pantocrator mosaic, Cefalu, Sicily by Chris Malcolm, on Flickr

 

[Lensflare]

I once had to time an exposure in between pulse beats to get it sharp.

I was in a cathedral which permitted photography but forbade tripods, trying to photograph a distant high mosaic in dim light. Luckily parts of my tripod could also be assembled into a monopod. I didn't want to discover whether the local Sicilian monks considered their ban of tripods also included monopods, so I secreted myself in the middle of a pew with people seated nearby all around. I knew I'd want to do a lot of shadow lifting in the shaded parts of the image, so I wanted the lowest ISO I could get, i.e. the longest exposure.

I tried clamping the monopod to the back of the pew with a strong hand grip. That made it very steady but I could see the regular ticking of my pulse in the magnified image. So I had to take the shot by timing the exposure to be inside the steady period between pulse beats, releasing the shutter with a radio remote to avoid shutter button shake. I reckoned 1/3 second exposure was the longest I had a fair chance of fitting into the steady period between pulses. On my 18-250mm zoom at 100mm that gave me f5.6 and ISO 160. It worked! The trickiest long exposure telephoto shot I've ever had to do!

The sharpest shot of the Pantocrator mosaic, Cefalu, Sicily by Chris Malcolm, on Flickr

Great story and a great bit of photography.