Question: Have everything in focus?

iflabs · Dec 11, 2009

Below is a shot I took of a model airplane (photo is cropped). The irritating thing is that I want the whole model in focus. As you can see, panning from left to right, focus decreases and eventually blurs. I used XSI with kit lenses shot in aperture priority mode with a wide aperture of around f/4.

Am I doing something wrong? Am I shooting up too close? Am I not using the wrong auto focus points? Am I suppose to focus manually?

Is this type of shooting considered macro photography?

DerekSalem · Dec 11, 2009

Well, first off, you want to focus on a middle-point (or do manual focus if you want as that will help you get a much more direct point of focus). It appears you focused on the nose of the plane which is farther away than the rest of the body.

Even if you focus on the perfect point, if your sensor isn't pulling in enough light from the whole subject it'll blur out parts. Try setting a small aperture (since you took it at f/4 try f/4.5 or f/5. You'll have to lower the shutter speed to accommodate (or raise the ISO), but you'll widen the depth of field, which is exactly what you want.

Josh66 · Dec 11, 2009

The more you stop down, the more will be in focus. After a certain point, sharpness will suffer though.

Try f/8... You will have more depth of field, and sharpness shouldn't be affected much, if at all. Even at f/8 (or more) you probably won't be able to get the entire plane (wing-tip-to-wing-tip) in focus, but the whole fuselage and both vertical stabs should be fine.

Get rid of all that background clutter too.

iolair · Dec 11, 2009

Agreed, try f8 or f11 to get the whole aircraft in focus.

Personally, I would put a background behind ... a big piece of white card would do, and digitally replace it with a photo of sky & clouds afterwards.

TJ K · Dec 11, 2009

Well a smaller aperture would be your best bet(big numbers) for everything in focus go for something like f/22 but that won't be optimum sharpness. Try shooting f/8-f/11 for the sharpest picture and you should be able to get most in focus. Also if you try backing up a little there will be less depth of field. GL
TJ

Overread · Dec 11, 2009

Hmm first thing I would do is dig out your old lightbox/tent - or setup a new one: Strobist: How To: DIY $10 Macro Photo Studio possibly using a blue background (because its a plane and all and white can get rather repetative over time

). That along with some lighting would give you better exposure and colour results (you will be able to lose that yellowy colour cast for a start); whilst also giving you some control over your background elements - rather than just random stuff.

I would strongly recomend the book "Understanding Exposure" by Bryan Peterson as a very good resource on exposure and exposure control as well as what and how the different settings affect your shots and how to use them in a creative manner. Its a very good book and many here strongly recomend it.

The background control is important because if you start to use smaller apertures (bigger f numbers) to get more depth of field, it will apply to the whole image - so those blurry background parts will start to become more defined and thus more distracting in the image. For a shot like this f8 is where I would start to work with apertures if I were going to get the whole image made with a single shot - I would then assess the end images and see if more depth of field is needed and use smaller apertures till I got to the depth I desired - however after f13 you will start to encounter diffraction and f16 or smaller aperture shots will start to be softer overall - something that you don't want. If the depth of field at this stage is still not enough for you you can do two things:

Firstly you can move the camera back from the subject (since the further the subject is from the camera the greater the depth of field is);
Secondly you can use something like Combine ZP (CombineZP News = go to here and then download the combinzp.exe file) and a method called focus stacking (more on this in a moment).

Focus - you mention focusing and this is very key in this line of work and something that if you use method 2 (focus stacking) you will need under your control. For this type of close up work and with a subject which won't be moving (and a camera which should really be on a tripod and thus also not moving) you can easily (and should) use manual focusing. Focus on the middle section of the plane and take a shot - it should come out well focused. For a model like this also check the angle you're shooting at through the viewfinder so that the sharp area covers not just the cockpit, but also runs down the main body of the plane to the end (as an aside watch your framing you clippped this planes back end off a bit). Autofocus can sometimes work but in this (and closer work) it can be a right pain with hunting for focus as well as missing what you want in focus (it tends to lock onto what it finds teh closest point to the camera - which is not what you want in focus in this case).

Is it macro photography? No is the simple answer, but the type of shot is closeup and the same methods apply for close up as for macro; save that things are little easier in many regards. So do do some reading on macro work for certain since you can use those methods in this type of shot.
For proper macro photography you need to get hte subject on the sensor the same size as it is in real life - so the subject is 1mm in real life and that reflects an image 1mm in size onto the camera sensor (called 1:1 magnification which is "true macro").

Focus stacking - you can google on this and get a lot of responces, so here is a quick overview - essentailly you take a series of shots, moving the focus point (but not the frame of the image) for each shot. Each time you overlap a little with the previous shots depth of field until you have covered the whole subject. Then you use the software (it looks all complicated but import the images needed into it for the stack and then just go to stack macro in the menu options - works much of the time - least its all I know at present).
Now as you can see manual focusing is the key to this method - so that you can control the focus exactly, but really the best thing is to move the camera for each shot - either closer or further, by a tiny bit to move the focus point. This helps to retain the same magnification level through the series of images, but in most cases simply adjusting the focus works well enough. Note that moving the camera is idealy done on tripod with a focusing rail (you can get them of ebay for not very much and they work very well)

Eventer · Dec 11, 2009

iolair said:
Agreed, try f8 or f11 to get the whole aircraft in focus.

Personally, I would put a background behind ... a big piece of white card would do, and digitally replace it with a photo of sky & clouds afterwards.

I agree that would look very cool, as right now the background isnt nice at all

iflabs · Dec 12, 2009

Thanks for the input all, but I'm still left wondering about focus points. What is the importance of setting a "focus point"? Is this merely a origin/reference point where the selected depth of field will take effect from?

Josh66 · Dec 12, 2009

The 'focus point' is the little dot in your viewfinder that lights up red. It's what the camera is focusing on.

KmH · Dec 13, 2009

iflabs said:
Thanks for the input all, but I'm still left wondering about focus points. What is the importance of setting a "focus point"? Is this merely a origin/reference point where the selected depth of field will take effect from?

Yes, it is a reference point that establishes where the DOF will fall.

DOF falls 1/3 in front of, and 2/3 behind the point of focus. Digital SLR's have multiple selectable 'focus points' so the photographer knows where that reference point is exactly.

Your cameras user manual will have a section on focus points and how to select them. The users manual will aslo discuss what focus modes, AF-S/AF-C/AF-A, your camera has available.

bhphotography · Dec 13, 2009

One thing I do is move further away and then zoom in. This will put more in focus at a lower fstop.

spudgunr · Dec 13, 2009

I played around with a depth of field calculator....it says if you move twice as far away, zoom in to double the focal length, you get the EXACT same depth of field. I don't know if that is accurate or not, but its what the online depth of field calculators said.

If you have a camera that has a smaller aperature zoomed in you will get more depth of field, but then you are changing aperature, so not really comparable.

If you need the wide aperature due to lighting, zoom out or move backwards and do a crop of what you want. The shorter focal length or extra distance at the same focal length will give more depth of field, then you can crop out the excess space (if you have the megapixels)