When you want shallow DOF

All,

I've been plinking around with relatively fast, normal-magnification lenses and diopters (Nikon 35mm f2, 55mm f1.4, and 85mm f1.8 with T6 a/o T5 closeups). These can give some really nice effects. I still need lots of practice, especially in selectively focusing on tiny features, and it won't give true macro (mag of 1 or higher). Still, I find some of the shots around my house kinda interesting (I haven't housed this combo; an early terrestrial attempt is below -- sorry to go all drypixel on you).

I think the light gathering is great: short 1.4 lenses focus FAST, even AF rather than AF-S, and the AF-ON button works well for these shots on my D70. And I do like the shallow DOF's potential, even if I have not realized it yet. I'm wondering if this would work underwater -- maybe even for some close-ups (vis-a-vis true macro) of critters -- maybe natural light at very shallow depths, or even using color-corrected focus lights deeper. Has anyone tried this underwater, and able to share results?

Thanks!

Chris

Just a bug on a daisy (uncropped). November is nice in Louisiana. I think this very ordinary scene gets something extra from being shot with so little DOF and without a flash, in the partial shade below a low sago palm:

And a 100%crop on the bug, showing my focus is a bit behind the eyes:

D70 - Nikon 50mm f1.4 with T6 and T5 -- shot at f1.4 and 1/1000s -- natural light

Hi Chris,

I've been doing a lot of thinking along similar lines but have no wet pixels to share with you either. When shooting with a very wide aperture the ambient light is likely so strong that even with the shutter set to the minimum synchronization speed the strobe is still not needed. So colour filters may be required when not close to the surface or you may need to go shooting near dusk or dawn. I've got a cheap 50mm F1.8 to do some trials with once I get on my next trip, hopefully around Xmas or in January.

Bart

It's much easier to achieve shallow DOF when you work at higher magnifications (even as low as 1:2 or 1:1). A standard macro lens at f/3.2 can do the job...

I've been playing around with this for a few months, but the response has been mixed. :glare:

When you want a really shallow DoF, use the lens blur

It's much easier to achieve shallow DOF when you work at higher magnifications (even as low as 1:2 or 1:1). A standard macro lens at f/3.2 can do the job...

 

I've been playing around with this for a few months, but the response has been mixed. :glare:

Matt,

In fact, your shots were part of what got me thinking about this. I'm still struggling with macro technique, and because of that I enjoy shooting the lower-magnification shots a bit more (as I refine buoyancy, composition, lighting, and most of all concentration -- which I find I need a lot of for near 1-to-1 shooting). So: aiming for a similar mood, but with a different scale of subjects.

Matt's right. Higher magnification helps. A larger sensor also helps. Here's one of my first shots after I got the 5D. Just testing the new toy. Shot with the 100mm macro at F/2.8 and ISO 1600.

I really like the looks of shallow DOF shots. I'll have to try more of it underwater the next chance I get.

While a shallow depth of field helps to isolate the subject, I think the DOF needs to be deep enough to cover the subject i.e. have all of the relavent subject in focus. Having some part of the subject in focus isn't good enough for my tastes.

Thus, I think careful selection of subjects and their backgrounds along with proper lighting is a better way to get subject isolation.

I agree with Peter. At the high magnification used in most macro situations you don't need to always open up to get that blurred background effect. This image was shot at F22 and I think has a pleasing subject separation:

Alex

All,

I recognize the value of the comments on magnification, sensor size, and lighting. All good, and true -- for what you want to do. What I want to do (and now I am feeling, pehaps, some of the heat Matt felt earlier) is different. I don't want high magnification; I am looking for larger critters. I want to be able to sieze chances to use natural light, when I can. And with the glass/bodies/housing I already have, I'm constrained to the DOF/COC of the Nikon crop for the forseeable future (and not lamenting it), and have to go the fast lens vs wider sensor path. Anyway, it's hard to get a handle on what these DOF comparisons mean between sensors: do you hold distance, mag or FOV constant? You get much different answers, as perhaps best explained by Bob Atkins here.

I know it's a matter of taste, and I have the luxury of shooting for no-one but myself. I admire razor-sharp shots, and beautiful strobe work. But that ain't the look I'm thinking of, here. It's not a matter of whether an image is good enough, but whether it evokes what I want. This (wide f, moderate mag) seems an appealing, minimalist way of shooting. It is a very gentle way of isolating, compared even to a diffused strobe or background.

Just by way of example, I (myself, just me) would have liked Alex' shot more if the focus were more selective: while the face is spot-on, I find the tendrils of algae are distracting, and f11 or even faster might have produced a shot that I would have liked better. I am not about to dress that up as a technical criticism, it's just what I am looking for (and still only dreaming of shots as good as Alex', too)

So again, thanks for your suggestions -- but I am looking for kindred spirits or exemplars in this approach, more than for corrections, this time.

Cheers and Peace,

Chris

Hi Chris,

Like you I'm not shooting for anyone but myself and I think it is perfectly ok to have your own look yhat you're trying to realize.

<FlameRetardantOn>For me, most shots with a diver "prominently swimming by" are too engineered to my taste. If that diver happens to also point his/her dive light towards the camera while swimming in crystal clear and bright blue water it is a complete turnoff for me. So this week's POTW gets a two-thumbs-down from me. No offense Claude, you are in very good company as I didn't start to realize this after seeing the umptiest diver-with-light shot in Martin Edges highly acclaimed UWphotography bood. So good on you!<FlameRetardantOff>

My point is that the generally-approved-on impressive shots may not appeal to everyone and if you don't have to please someone who is paying you then why not try to capture the kinds of images that make you look at them again and again and again. Your description of using shallow DOF outside the normal macro context sounds promising to me and worth the try. Of course, if you try a technique that is not commonly practised you may end up finding out that there was a good reason why no one is using it. On the other hand some techniques may be so ingrained that we need some rebels to break out of the box. I haven't read anything so far saying that your plan is bound to fail so I hope you go ahead and just do it and let us know how it worked. If I get my act together I will be experimenting with this as well, although more in a smaller fish/higher magnification context.

Good luck!

Bart

"some techniques may be so ingrained that we need some rebels"

Absolutely!!! With digital we have an ever expanding horizon of techniques available to us (not all yet though as you might see from my post on corner sharpness and wide-angles) but many conventional techniques are still rarely utilised underwater. Rebellion sounds great.

Back on topic, this shot was taken on a 100 macro at f/11 on a FF Canon. My aim was to retain sufficient background to illustrate the fact that the fish is mimicking a cobble or pebble like the one behind him. Too sharp a background and the fish merges, too out of focus and it doesn't work. Depth of field is a tool which is very useful, but, it needs to be used together with very careful lighting - I use a wide-beam strobe for macro to spread even lighting but have to say that I rarely find diffusers (which I don't use anymore) to give as effective a light as purpose built wide beam strobes. This is one of my hobby horses.

Paul and Bart,

Thanks for your comments. There are kindred souls out there.

Unfortunately, I won't be diving for a while, so won't have a chance to try this out subaqua soon. Fortunately, I will be going to Corcovado NP (Costa Rica) over my winter break, and will try this and conventional macro out on bugs and flowers that are much more interesting than anything in my yard.

Cheers,

Chris