Aperture setting vs Depth of Field in macros

[Khay]

Since some people seemed to have some doubts about what changing the aperture settings on the camera does for a photo, I did this little animated .gif from a sequence of photos I took a few days ago :

http://khayman.planetaclix.pt/web_photos/BB_Merkur-Slant-Bar_anim.gif

As you can see, the camera was focused on the closest spot (the tip of the handle is always in focus) and at that distance, taking a shot with f/2.8 (effective f/3.2) results in a very shallow depth of field - practical result of which, the head of the razor is out of focus. As the aperture increases, so does DoF, which ends up in a picture that has the razor almost totally in focus.

So does this mean we should always take the shots at f/32 ? as always, it depends :biggrin: There are downfalls for such small apertures, and in most lenses, you start to lose sharpness after f/16 because of all the light difraction inside the lens (you're taking a photo through a pinhole). Also, as the aperture increases the shutter speed decreases which will result in having to have a tripod or something similar for the long exposures.

Hope that helped!

[Jim]

Perfect explanation and demo!

[Spotter]

Nice work, thank you

What type of camera are you using?

Spotter

[Khay]

Nice work, thank you

What type of camera are you using?


Thanks.

I used my Nikon D200 SLR + 60mm macro lens for these.

[DoubleE]

Nice job!:a14:

[Spotter]

Thanks.

I used my Nikon D200 SLR + 60mm macro lens for these.

Wow nice camera !

I am just a amature photographer using a Nikon D80 but I love it.

:001_smile

Spotter

[2bits]

A picture is worth 1k words

Moving pictures 10k

Good job!

[Haiku]

Marvelous demonstration. Thanks for taking the time and making the effort to do this. :thumbup1:

[Roman414]

Good job. You summed it up very well. It is a trade-off. Smaller aperture means longer exposures and/or faster film. You do need a tripod or a bean bag for sharp pics.

[Khay]

Wow nice camera !
I am just a amature photographer using a Nikon D80 but I love it.


Yeah, the D200 is a nice camera - I had the D80 predecessor, the D70 and loved it, apart from the viewfinder which I thought it was quite small - but I picked up a D200 at a shop and tried it, I really liked it and ended up getting one.

[Khay]

Good job. You summed it up very well. It is a trade-off. Smaller aperture means longer exposures and/or faster film. You do need a tripod or a bean bag for sharp pics.

Thanks ! and indeed, for the longer exposures a good tripod or any other good method of placing the camera at a stable position is mandatory.

Apart from that, the problem is usually the lighting - and when taking photos of shiny chrome objects, the reflections / highlights and bright spots that can always appear.

For the shots above, I used the Nikon D200 / 60mm macro lens and a tripod.

The lighting was done with 2x 500W lamps with halogen bulbs from a hardware store (one on each side, about $10 each) and to avoid hard shadows I built a makeshift paper "tent" with 6 or 7 sheets of letter sized white paper and adhesive tape (cheap lightbox :biggrin: )

For people who are new to macro/photography - you don't need a D200/macro lens to make similar shots to the above - the contribution of the cheap lighting/taped paper diffusor was much more important to the final result than the camera/lens itself :

On the following photo, I didn't put the paper light box around the razor, and I just had the regular room lighting on. Due to the particular spot where I was taking the photo, I had uneven lighting, bright shiny white-out spots. Not really nice :

http://khayman.planetaclix.pt/web_photos/BB_no_diffused_lighting.jpg

On the next one, I put the paper light box around the razor and turned on the halogen lights - lighting is much softer now, and the bright shiny spots on the tip/handle disappeared but the image has got a yellow cast - this is due to auto and the camera being confused by the fluorescent room lighting and the two halogen lights in front of it (very different white points):

http://khayman.planetaclix.pt/web_photos/BB_incorrect_white_balance.jpg

Re-calibrated for the correct white balance on the camera (would need to close down on the aperture to focus the head properly though) :

http://khayman.planetaclix.pt/web_photos/BB_bad_reflection_on_handle.jpg

For the shots in the beginning of the page I did reposition the razor more carefully to avoid unwanted background reflections appearing on the chrome (like that black bar along the handle you see above). That wouldn't be so much of a pain if I was using a "proper" light box, but you can't beat the price of 6 sheets of white paper :biggrin:

What a D200+macro lens gives you is the ability to do something like this easier than you'd do with a compact (Merkur logo from the handle of the above slant) :

http://khayman.planetaclix.pt/web_photos/BB_merkur_logo.jpg

[stupidyank]

Hope this isn't too photo geeky,

I would say shoot it all in f32 if you want everything in focus. because the focus range is so much smaller in a macro lens you won't end up with everything in focus any other way. Well, there is one other way, you could compose your shots differently making sure that the film plane (sensor plane in this instance) is parallel with what you are shooting. I.e. taking a picture of a razor lying flat on a table with the camera directly above and parallel with the surface of the table and thus the razor. Even if you do this you will have to increase DOF via decreasing the aperture, but not nearly as much as you would have to in order to do the sort of shots you have posted on this thread. (with of course the exception of the logo shot)

But in reality this is a moot point unless you are making posters out of these shots. you really won't see much distortion because of small size of the aperture.

[Mr-Scruffy]

I remember reading that stuff years ago. Great pictures. Thanks for refreshing my memory.