DOF and Macro - please help a complete numpty
DOF and Macro - please help a complete numpty
Author
Discussion

zhastaph

Original Poster:

231 posts

254 months

Wednesday 17th August 2005
quotequote all
[pic]http://www.zhastaph.com/pics/DSC_1515_web.jpg[/pic]

Ok, I'm a self confessed complete numpty when it comes to this photography lark.

I have a photo of this spider which is [i]ok[/i], but it would be soooo much better if it was properly in focus every place.

Now I understand as much to know that this is depth of field, and I [i]think[/i] that to make the depth of field deeper with Macro work then I need to make the apperture smaller {bigger f number??}.

The above picture was taken with the camera in Close Up Mode {the picture of the flower}.

I've tried messing with this, I've put the camera in Aperture priority mode and played with all sorts of aperture settings going all the way down to f/32. I find that for sure a lot more seems to be in focus, but the whole picture as a whole doesn't come out as sharp as when it's on '[i]flower mode[/i]' - even if I set the aperture to f/5.6 it still isn't as sharp.

Can anyone tell me why please and how i can get this better {in simpleton terms please :)}

The kit I'm using is;

Nikon D70
Sigma 105mm 1:1 macro lense
Tripod & Infra Red remoty thingy

Fankoo :)

GetCarter

30,657 posts

301 months

Wednesday 17th August 2005
quotequote all
Yo

Now I'm no expert as I've just got into this macro lark, but:

What I've found works is:

MAKE SURE IT'S SUNNY (unless you are using fill in flash)

Put camera into manual focus

Extend camera to 1:1 maximum

Put camera into either speed or apature priority mode (or manual) and as you say, make the DOF the widest (slowest speed or highest f number)

Here is the tip... move the entire camera and lens (and you) in and out not focusing with the lens.

Then... take lots!

..and the more light that you have, the more DOF you can get - the more subject is in focus

My first (some dodgy) efforts here:

www.stevecarter.com/macro/macro.htm

have fun (and hope it's not windy!)

Steve



>> Edited by GetCarter on Wednesday 17th August 19:53

mindgam3

740 posts

258 months

Wednesday 17th August 2005
quotequote all
I've only just started photography myself but I presume that the camera is too close or unable to get the whole of the spider in focus even with a large aperture.

With bigger apertures the more likely, more of the image is to be soft or out of focus which may also be hindering.

Maybe try zooming out a bit and/or moving the lense further away from the subject.

I'm no pro so i'll leave someone else to give you a proper answer but some food for thought

dcw@pr

3,516 posts

265 months

Wednesday 17th August 2005
quotequote all
something to bear in mind is that once you get to f/16 and smaller the image quality starts to degrade due to refraction (or is it diffraction, I can never remember), so if possible I wouldn't go down that far

_dobbo_

14,619 posts

270 months

Wednesday 17th August 2005
quotequote all
Use the depth of field calculator to determine what aperture you need to use to get the whole spider in focus.

It will tell you nice things like at 105mm you should use f/16 to have 1" worth of subject in focus, and you need to be 3 feet away, etc etc.

simpo two

90,862 posts

287 months

Wednesday 17th August 2005
quotequote all
Everything you say is true and you're doing everyhting right. But this bit:
zhastaph said:
I've put the camera in Aperture priority mode and played with all sorts of aperture settings going all the way down to f/32. I find that for sure a lot more seems to be in focus, but the whole picture as a whole doesn't come out as sharp as when it's on 'flower mode' - even if I set the aperture to f/5.6 it still isn't as sharp.

- foxes me. 'Flower mode' can't do any more to decrease aperture than you can do manually. But then you say 'f5.6' which will give less DOF...

I'm with GetCarter on this one - do what he says and eventually you will get a usable shot. But in the macro world DOF is vanishingly small, it's one of those laws of physics things. You just have to be very careful to nail the bit you want, eg:

gopher

5,160 posts

281 months

Wednesday 17th August 2005
quotequote all
_dobbo_ said:
Use the depth of field calculator to determine what aperture you need to use to get the whole spider in focus.

It will tell you nice things like at 105mm you should use f/16 to have 1" worth of subject in focus, and you need to be 3 feet away, etc etc.


I found this very useful - thanks dobbo, I think I may be refferring back to that a lot, it has certainly helped to clarify a lot of "stuff" I was trying to work out!

Cheers

Paul

simpo two

90,862 posts

287 months

Wednesday 17th August 2005
quotequote all
Don't forget the D70 has a handy DOF Preview button. Saves taking a calculator and ruler with you

zhastaph

Original Poster:

231 posts

254 months

Wednesday 17th August 2005
quotequote all
Here's me trying to get my spider, cunning little feckers they are



I tried enticing him out into his web by wobbling it a bit with a stick - he'd kinda move a bit and think "Hmmmmm"

Then I dropped the stick and it was dangling from his web, you have never seen anything move so fast in your entire life - scared the sh1t out of me

He come out examined the stick, then it fell. So off he goes back into the corner and that was it. Nothing else I did would bring him out, he was having none of it - it's like he knew


That depth of field calc is excelent, more than anything else it gives me a better understanding of what's going on. I'm gonna try your suggestions Mr GetCarter, more light means less shutter time, means sharper image - right?

I'll get there

zhastaph

Original Poster:

231 posts

254 months

Wednesday 17th August 2005
quotequote all
Simpo, I've got a book with pictures in about my camera and it says about the DOF preview, so I treid it - mayb it's me and mayb I'm completely dumb but after I press it and it goes click it still looks the same - so I gave up

agent006

12,058 posts

286 months

Thursday 18th August 2005
quotequote all
zhastaph said:

I have a photo of this spider which is.....
...now the reason why i'll not be able to sleep tonight.

Please post links to spider pics. Please.

Kinky

39,898 posts

291 months

Thursday 18th August 2005
quotequote all
agent006 said:

Please post links to spider pics. Please.



Spider pic

K

I'll get me coat

zhastaph

Original Poster:

231 posts

254 months

Thursday 18th August 2005
quotequote all
agent006 said:
...now the reason why i'll not be able to sleep tonight.

Please post links to spider pics. Please.


Awww, but they're such a pair of ickle cuties

>> Edited by zhastaph on Thursday 18th August 17:11

page3

5,132 posts

273 months

Thursday 18th August 2005
quotequote all


You might have put a 'spider warning' in the message title

te51cle

2,342 posts

270 months

Thursday 18th August 2005
quotequote all
For your first efforts try focussing on the eyes and take a series of shots with different f-stops so that you get a feel for how much depth of field you're actually going to get. Try f8, f11, f16, f22 and f32. It'll probably vary from hardly anything to not very much at the kind of magnification you're looking at, and you may find that you prefer the limited DOF shots at f8. Make sure that any softness is not cause (a) by camera movement and (b) by the little git not wobbling about just as you take the picture 'cos like you say, they know what you're doing and will do their level best to ruin the shot for you !

If you want to get the whole spider sharp ten you will probably have to take a shot with the back of your camera parallel to the back of the spider - the 'squashed flat' look !

simpo two

90,862 posts

287 months

Thursday 18th August 2005
quotequote all
zhastaph said:
mayb it's me and mayb I'm completely dumb but after I press it and it goes click it still looks the same - so I gave up


Well, with an SLR you normally view the scene at max aperture for max brightness, then the aperture jumps down to the correct and/or set one when you press the button. So if your exposure was using max aperture anyway, you're right, nothing would happen. Now set the camera to Aperture Priority mode and dial in a smaller aperture, say f16. Try the DOF preview again. Apart from the view getting darker, you shoud see, if you look carefully, more DOF.

Nb For your spider shot I think you were a victim of your tripod; ie it doesn't have the fine adjustment needed for macro, at least not over the kitchen sink! I would try handheld, making sure there's enough light for a decent shutter speed, and brace myself against the wall. That means you can make instant millimetric adjustments as the critter moves. If it's too dim, get a light or hoof the ISO up.

>> Edited by simpo two on Thursday 18th August 19:55

thunderstruck

8,838 posts

304 months

Thursday 18th August 2005
quotequote all
GetCarter said:

www.stevecarter.com/macro/macro.htm


The dog's nose and raindrop are stunning shots