The Forest Floor & Depth of Field/Focus

[ShaneS]

I really want to like this shot but I think that it needed a little bit more depth of field...



I was sitting on the forest floor about a foot away from the front plant which was what I focused on. This was shot at f16 at 55mm (crop camera) so I was expecting a bit more depth of field.

I would have liked to see the second and third cacti (???) in better focus and then have it drop off. Should I have focused on the 2nd cacti? Would that have allowed the first cacti to remain in sharp focus?

The depth of field calculator on this site says the with my settings I have a very narrow range of sharpness from .97 feet to 1.03 feet and it seems like that doesn't change much with different f-stops and focusing distance. Am I missing something here? How would I achieve my goal to widen the range of focus?

The scene was very pretty in color but was tailor made for black & white due to all of the distracting stuff on the forest floor. Also, I'm testing out a border on this one which I don't usually do for presentation here.

[Polar01]

yes the lens what you used, try entering 35mm at one foot at f/16 and see what you get. As the mm's increase you need to be farther away for the subject to get a better DOF.

Cheers: Allan

[bnnrcn]

Hi Shane I find the composition crowded but if you crop the image from the top of the 3rd cacti IMO it will look much better and out of focus 3rd cacti won't look bad anymore. The white border matches the cacti's colour well. You might as well try a thinner one to see how it works.

[ShaneS]

Allan, I guess what I am confused about is how you compose a shot in this situation where a severe crop isn't necessary. I get that my depth of field would increase at 35mm but so would the amount of the surrounding area in the frame, right?

Binnur, thank you for your suggestion, but as I said above this was already a pretty severe crop so it will be going into the almost bin (that bin is frustratingly full) and I won't be working on it anymore - I just posted it as an example of the problem that I was having with depth of field.

[Mike Buckley]

A few ideas, Shane...

Judging by the shutter speed, you were using a tripod. You could have used manual focus and Live View. You could have magnified the image in Live View to see what parts were and were not in focus. When I do this, I always make sure the very most important part of the image is in focus. Whatever isn't in focus, I can't do anything about that.

You used f/16. For this kind of image, you need to use the smallest aperture. Perhaps a smaller aperture was available, perhaps not.

This is the sort of image for which I like using my 35mm prime lens. It allows me to focus at as little as 9 inches. I see that your focal length was 55mm, so I wonder if you were using a zoom lens. If that's the case, I also wonder if you were limited by the lack of a close focusing distance that would have allowed you to move in closer using a shorter focal length and if you were limited by the lack of smaller aperture settings.

Last, this is the kind of image that some people will use a tilt-shift lens to keep everything in focus. Others will use a lens like yours to capture several images using focus-stacking technique and then using focus-stacking software to combine the images into one file.

[Stagecoach]

Hi Shane

I really want to like this shot but I think that it needed a little bit more depth of field...

I would have liked to see the second and third cacti (???) in better focus and then have it drop off. Should I have focused on the 2nd cacti? Would that have allowed the first cacti to remain in sharp focus?

The thing to remember in this situation is that roughly a 1/3 in front and 2/3 behind will be in focus from your focus point. This goes to close to 1/2 in front to 1/2 behind as you reduce subject distance to minimum. So if you knew you wanted only minimal distance in front of the forward flower possibly the second flower should have been what you focussed on.

This all depends upon the DOF you are going to achieve with lens FL, subject distance and aperture, can all be measured and calculated on site, but in practical terms use of Liveview as Mike mentions or DOF preview would assist greatly.

How would I achieve my goal to widen the range of focus?

a) Move back (increasing subject distance) photographing more in the scene and then crop in post.

b) Use a smaller aperture.

Remember that whatever Focal Length lens you use to take the shot, if you frame it the same in camera your DOF will be the same.

Grahame,

[ShaneS]

Thank you Mike & Grahame for the clarifications. Seems like cropping would be in order not matter what I did.

Mike I had my 55-200mm on the camera as the main goal was to do some partial shots of tree trunks in the forest and I wanted to compress the distance between the trunks. None of those shots were great but I didn't want to change the lens. So overall it was an nice outing in a park that I hadn't been to in the past and a learning experience. I will go back and try again armed with some new knowledge

[Polar01]

Shane really the only way to do a shot of this type is with as Mike stated is with a tilt-shift lens, have rented these in the past, great fun, shots like this will be tack sharp front to back. The only problem is a 45mm tilt-shift from Nikon will set you back about $2200.00 CDN I think that once you learn how to use it you will use it a lot. So for fun try renting one for a week and run off and play in the woods, then see what happens.

Cheers: Allan

[ShaneS]

Thanks Allan! That lens is definitely not in my budget...but good idea on the rental.

[ajohnw]

There was some discussion on this area a while ago. I posted a chart in it that can deal with this sort of situation. There is also some information on using framing to determine depth of field when that is more appropriate.

Depth of field 2/3 behind and 1/3 in front???

I suspect that the chart will show that Shane would need to use a shorter focal length lens but cropping can always be used. The chart is based on the same approximations as the usual dof calculator but relate to the size of items that will be captured by the sensor. The distance is simply from the camera - what ever the distance is to where it is actually focused. I've tried it a couple of times and so far it works.

John
-

[Polar01]

Shane if you took that with your 55-200mm you did very well indeed, as Nikon list the minimum focus distance for that lens as
3.1ft and if it is VR than 3.6ft, you state you were about 1ft away so again well done. At the distance you were DOF is not going to help you, as DOF is also a relationship of the f-stop used and the distance from the lens. If you had keep all the settings the same and moved your rig 2ft farther away you would have seen an increase in DOF, however the subject in the viewfinder is smaller so you would have to crop. This is again where the tilt-shift comes in to play, I know that if I had one it would likely be on my camera about 70% of the time. Again if you were that close you did damn well, great shot.

Cheers: Allan

[Shadowman]

Shane,

I think part of the problem is you've got similar light tones throughout the image and it's making you see something that's not really there, mainly an in-focus element in the background. I think the lightly toned flower in the upper left hand corner is affecting what you've achieved with your camera settings.

[ied]

Shane, this thread has been most informative. thanks for sharing.

Irene

[ShaneS]

Thank you for the additional comments and tips! They are appreciated and part of why I love CiC