Depth of field - which aperture?

[Photograficus]

Hi

I just bought a 300mm Tamron lens (70-300mm f / 4-5.6) for my Nikon D3500. Yesterday I was out photographing insects.
This insect is not sharp on the wings - only the head ...
I want the whole insect (see photo) to be sharp and focused on the largest magnification (300mm).
Which aperture(s) should I choose to have the depth of field corrected?
Attached photo is taken on aperture f9, 1/500 sec. and iso 1250.


f9, 1/500 sec. and iso 1250.

 

[Klaus dk]

The smaller the aperture (higher f/number), the deeper the DoF. I'd try f/16 or f/22 for a start.

Note that all lenses will lose sharpness at smaller apertures, the term for this is "Diffraction Limit".

For sufficient DoF on macro shots, you will often need focus stacking.

Good luck and good light.

 

[David1961]

The fact that you haven't stated the focus distance suggests you are not sure what determines or affects DOF. Shutter speed and ISO do not affect the DOF.

For a given sensor size, DOF is determined by aperture, focal length, focus distance to subject and a thing called the Circle of Confusion.

 

[AnthonyL]

As others have said you can close the shutter more (f/11, f/16) but I'm not sure you hit focus on the head that well and I would have expected sharper.

http://dofmaster.com/dofjs.html will let you play with some DOF figures.

Be careful that you don't go nearer than the minimum focus distance for the lens. For stationary object if there is no wind you can decrease the shutter speed to compensate for the smaller aperture rather than increase the ISO any further.

Just experiment on a twig or some other small inanimate object first in similar lighting and surroundings.

 

[Mark S Abeln]

What you are trying to do is “macro photography” which is a specialized topic. I would suggest Googling that for more information. Yes, limited depth of field is always going to be a problem, and increasing the f/stop value should help.

 

[Gerry Winterbourne]

As others have said you can close the shutter more (f/11, f/16) but I'm not sure you hit focus on the head that well and I would have expected sharper.

http://dofmaster.com/dofjs.html will let you play with some DOF figures.

True in general but the standard DOF calculations break down at very close range.

Be careful that you don't go nearer than the minimum focus distance for the lens. For stationary object if there is no wind you can decrease the shutter speed to compensate for the smaller aperture rather than increase the ISO any further.

Just experiment on a twig or some other small inanimate object first in similar lighting and surroundings.

 

[Gerry Winterbourne]

Hi

I just bought a 300mm Tamron lens (70-300mm f / 4-5.6) for my Nikon D3500. Yesterday I was out photographing insects.
This insect is not sharp on the wings - only the head ...

It isn't the sharpest zone is behind the head; the head itself is quite blurred.

I want the whole insect (see photo) to be sharp and focused on the largest magnification (300mm).
Which aperture(s) should I choose to have the depth of field corrected?

DOF gets less as you get nearer the subject. Although this is not strictly speaking a macro photo it is getting close. Use the smallest aperture (largest f-number) your lens allows (F/22?). Such a small aperture will lose some overall sharpness because of diffraction but for "macro" work that's preferable to losing DOF.

Attached photo is taken on aperture f9, 1/500 sec. and iso 1250.

If your lens is stabilised you can go below 1/500s. If not, ISO will have to increase. 1/500s at f/22 is a low exposure so you may suffer noise; but, again, that's a sacrifice to gain adequate DOF.

f9, 1/500 sec. and iso 1250.

--
---
Gerry
___________________________________________
First camera 1953, first Pentax 1985, first DSLR 2006

Galleries by Gerry Winterbourne

www.pbase.com

[email protected]

 

[Bob]

Find something about the size of a dragon fly and experiment with it. You'd learn a lot more about your gear that way.

Is AF reliable on something so small and surrounded by other things (blades of grass)? Or should you use manual focus instead?

How slow can you go with the shutter without getting motion blur?

Does your lens have VR? How useful is it?

What aperture gives you the right amount of DOF?

 

[LordKOTL]

Hi

I just bought a 300mm Tamron lens (70-300mm f / 4-5.6) for my Nikon D3500. Yesterday I was out photographing insects.
This insect is not sharp on the wings - only the head ...
I want the whole insect (see photo) to be sharp and focused on the largest magnification (300mm).
Which aperture(s) should I choose to have the depth of field corrected?
Attached photo is taken on aperture f9, 1/500 sec. and iso 1250.


f9, 1/500 sec. and iso 1250.

This may be rehashing a lot of other points other have made, but you're getting into the realm of near-macro, and that opens up a can of worms. For moving insects you can't really focus stack for more DoF, and a tighter aperture causes diffraction which means either a slower shutter speed, which might not be possible in natural light, or a higher ISO to lighten things up.

When I shoot similar stuff I tend to tighten my aperture WAY down--like f/32 or more, and then use flash--with my shutter near the sync speed and the ISO as low as it can go with an acceptably lightened image. The flash can take care of both the lighting and stopping motion, but it also comes with some issues--like a pop-up might not be powerful enough with the tight aperture and sync-speed shutter so you'd need higher ISOs, possible shading of the subject via the lens hood, the ability to have the flash off of the camera (not necessary but does make for better lighting and negates the hood shading the subject), the flash not being powerful enough at longer distances, and of course owning a flash that can do all of that.

Good luck and happy shooting.

--
There's no shame in using auto or semiauto modes--no matter what the salesdroids at Best Buy tell you.

 

[JasonTheBirder]

For that size insect, the only way to get pretty much all of it in focus and to have it decently sized in the frame is to shoot it parallel to the focus plane; that is, in profile. If you do that, you don't even need a very small aperture. F/8 will do the trick.

If you shoot it on an angle, expect an out of focus region. That can be used in composition, but then the best part to get in focus is the head and it might take a few tries to do that.