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STICKY CLOSED Focus Blur Technique - what & how? My guide to FBT

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Allyeska is a group administrator Allyeska says:

My Guide to Focus Blur Technique
This is a summary of various ways I have experimented with focus blur. By no means is this an exahaustive list. If you think of something not mentioned here, please do share it with us!

What is focus blur technique?

Changing the focus in or out during a long exposure.


* Canon 400D or 550D (DSLR) –any camera that allows manual settings of ISO, aperture and shutter speed, and manual focusing during an exposure is fine.
* Tripod – a tripod is necessary for deliberate, clean shots when you do not want camera shake affecting the photo. However, sometimes you may choose to hand hold the camera and utilise motion of the camera in creating your image.
* Any camera lens – it doesn’t matter if it is a prime or a zoom, wide angle or telephoto. Keep in mind Depth of Focus of the lens – the narrower the DOF, the more pronounced focus blur you will obtain. I have found that standard kit lenses produce the best results (turning the focus ring on kit lenses seems to change focus faster than on better quality lenses).


* Focus blur is incredibly effective when shooting fireworks. The brightness of the subject and their fast moving nature make them an ideal subject. LED lights and Christmas light decorations are good subjects too.
* DOF of lens is worth considering (wide angle will produce less pronounced focus blur than a mid range or telephoto lens), but to maximise focus blur on any lens, just open up the aperture.
* The best tip I can give is to make tactile markers on your lens so you can feel when you are in focus during an exposure in the dark. I do this by focusing the lens on the subject or where I expect the subject will be. Then I place a marker (several layers of 1cm square cuts of gaffa tape, layered on top of each other to make a little bump) somewhere on the part of the lens that does not rotate. Place this first marker in a position that is comfortable for your hand to rotate in and out from, and at the edge of the focus ring. Then place another marker of layered gaffa tape adjoining the first marker, but on the focus ring. As you take the subject out of (and back into) focus, keep your finger on the marker on the focus ring. This gives you an idea of how far you have taken the subject out of focus. If you want to bring your lens into focus you will feel the stationary marker come underneath your finger and line up next to the marker on the focus ring.
* Remember that the more out of focus you take the subject, the darker it will be. For example, with fireworks, they will appear brightest when the light trail was in focus, and fade in intensity as the light trail becomes out of focus.
* Subtle focus blur can create dreamy portraits.
* if shooting fireworks, get to the venue early to set up camera gear and tripod, and attach your focal markers.
* get to know your camera before trying focus blur. Become familiar with the manual mode and how to change ISO, aperture and shutter speed so you can do so quickly and easily during fireworks and in the dark.
* Ensure you battery is fully charged as shooting constantly during fireworks will drain your battery.
* Ensure enough space on your memory card to allow for lots of photos – you don’t want to be changing cards in the middle of the show!
* Check your first few photos to ensure correct exposure. You don’t want to take 50 shots to discover they are all blown out.
* Randomly stop and check the last few photos to see what sort of effects you are achieving to determine if you need to revise your technique. It’s better to miss snapping a few fireworks to find out part way through that you were changing focus too slowly (as an example) as you then have the rest of the show to revise your technique until you get what you want.
* when you randomly check previous photos, also think about shutter speed. Is the shutter speed too short and not allowing enough focus blur? Is the shutter speed too long and creating a cluttered photo with too many fireworks and blown out bits / underexposed focus blur?
* most of all, experiment! Don’t be disheartened if you don’t like what you get on your first attempt. Or if like me, you love the results of your first attempt but later attempts don’t work so well. Keep trying and experiment with technique until you get results you like.
* join the Flickr group I created to discuss focus blur and share the results www.flickr.com/groups/focusblur/

There are a myriad of ways you can do focus blur:


1. Start the shot IN focus, and take it out of focus (IN>OUT)
Australia Day fireworks

2. Start the shot OUT of focus and bring it into focus (OUT>IN)
Australia Day - fireworks

3. Start out of focus, move through correct focus and back to OUT of focus. (OUT>IN>OUT)
christmas focus blur

4. Start in focus, take it out of focus, and then back in to focus. (IN>OUT>IN)
No example as yet.

5. Start out of focus, take further out of focus (OUT>OUT)
xmas 08: focus blur fun

6. Any combinations of ins and outs you can imagine!


(for the sake of consistency, examples of focus blur are using shutter speed of 6 seconds. The exposure, however, may be as short or as long as is feasible)

1. Change the focus slowly and gradually
( ie 6 second exposure, the rate at which you change the focus is consistent over the 6 seconds, focal change is slow, resulting in small change of focus)
Canberra Show - focus blur fireworks

2. Change focus quickly but gradually
( ie 6 second exposure, the rate at which you change the focus is consistent over the 6 seconds, focal change is large, resulting in large change of focus)
xmas 08: focus blur fun

3. Change focus quickly, and sharply (NOT gradually)
(ie. 6 second exposure, have focused for 2 seconds, quickly take out of focus and expose for 2 seconds, quickly take it further out of focus and expose for remaining 2 seconds).
xmas 08: focus blur fun

Mix'n Match

Try any of the focus patterns with any of the speed patterns together!


Moving subjects
Use focus blur techniques with a moving subject (eg cars, fireworks)
Aust Day fire works - focus blur yay!

Stationary subjects
Use focus blur techniques with objects that are stationary (eg christmas lights, christmas tree)
christmas focus blur

Moving the camera
Use focus blur while moving the camera - pan the camera side to side, turn it on its axis on a tripod, zoom, or hold it by hand and make random movements.

xmas 08: focus blur fun

xmas 08: focus blur fun

christmas focus blur

Originally posted at 6:24PM, 1 January 2009 PDT (permalink)
Allyeska edited this topic 114 months ago.

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