Elmerviking

I have a Tokina 100 mm atx pro macro lens on my Nikon D7100. Shortest focusing distance is 11 inches at life size reproduction (1/1).
The depth of field is VERY shallow, only a few mm. If I chose a macro lens with much longer minimum focus distance, for example a 200 mm macro lens, and do a life size photo, will the depth of field be shallower or the same?
Or, in other words, do the focal lens on a macro lens affect depth of field so that a longer focal lens will be much more critical when it comes to focusing correctly ?
Will it mean that you have to compromise between depth of field and minimum focusing distance when you chose a macro lens?
/Bosse

RWR Loc: La Mesa, CA

Depth of field is dependent upon the reproduction ratio and f/stop - the only thing a longer focal length gets you is a greater subject distance.

Elmerviking

Thank You for your quick response!
I actually did a Google search and found that DOF depends on reproduction ratio, aperture AND focal length, but how the focusing distance affect DOF with different focal length and identical reproduction ratio can be neglected!
Tha was what I originally suspected but wanted to be confirmed.
Thanks again
/Bosse

sippyjug104 Loc: Missouri

Good question. I shoot macro photography out in the fields everyday that weather permits. I have a 60mm, 105mm and a 200mm macro lenses for my Nikon D810. The depth of field is exactly the same on all three lenses when I shoot them at the same f-stop. What does make a difference is that each of the macro lenses have a different minimum focus distance. So with that said, depth of field is directly related to the f-stop aperture setting.

The 60mm is great for studio work, flowers, and subjects that you can get very close to safely. The 105mm is a good sweet-spot length for most applications and it is a favorite length of many macro photographers. The 200mm is my favorite choice for skittish insects and those that potentially may sting or bite if I get my face too close.

I found that the best f-stop for me to be between f-11 and f-16. At less than f-11 the depth of field is so shallow that only a small area of the subject is in sharp focus. Less than f-11 may be great for flat surface subjects like stamps and coins but not for 3D subjects like a live insect (unless you can do focus stacking).

If I go over f-16 lighting the subject becomes critical and even more so with a 200mm macro lens (good practice for hand-held shooting is to double the focal length as the shutter speed) for I shoot at 1/360th sec.

When I have the available light and the power of the flash, if I shoot over f-22 and up to f-32 I start to get diffraction which is inherent in a narrow aperture which causes the sharp edges of the subject to appear softened so it is counter productive to the goal of highly detailed macro photography.

Elmerviking

I guess you mean all lenses you mentioned have the same DOF when you shot at the same aspect ratio?
Macro lenses would be totally worthless if DOF only depends on chosed aperture. I can not imagine a portrait with my 105 mm lens if it had a DOF of a few mm at a distance of 3 meter!

sippyjug104 Loc: Missouri

I agree with you and perhaps I wasn't clear in the comparison of my three different focal length macro lenses. I believe that the depth of field is dependent upon the three factors which are aperture value (f-stop), focal length (the mm of the lens) and distance to the subject from the camera's sensor (which in my case is the centerline of the camera body).

When comparing my three macro lenses, two variables must be fixed. If I set a larger F-stop number (closing the aperture) will result in a larger DOF. Using a longer focal length will result in a smaller depth of field and shooting at a closer subject to sensor distance also results in a smaller depth of field.

Like you, I love my 105mm and it is capable of shooting to infinity. If I take a picture of my dog sitting on the table using a tripod, the distance and the lens length are set. Increasing or decreasing the aperture f-stop increases or decreases the depth of field. At 105mm set at f-2.8 I can get his eye tack sharp and the background slightly past him is a soft blur. Without moving my dog or my camera, if I set the aperture to f-16 or more the background also is tack sharp.

In closing, what I meant to say was I can get the same result of depth of field with any of my three lenses by changing any two factors and to me, distance is the most important when photographing wasps and hornets as I most often do.

Elmerviking

Thank you!
You are absolutely right and I appreciate your clarification. A lot of “experts” disagree, but I think a correct answer is important for rookies and technically interested persons.
I totally agree with everything you said!
Thanks again...and cheers!
/Bosse

Leitz Loc: Solms

How about posting a picture of your dog sitting on the table using a tripod?

sippyjug104 Loc: Missouri

This is our young male Smooth Fox Terrier, Axel (sometimes I call him Axe-hole when he misbehaves). I shot this with him setting on the grooming table with my Nikon D810 on a tripod with an 85mm f1.4 lens. The white behind him is our white vertical blinds and the brownish color is the wall. I had the grooming table setting about 2-ft. from the window for I wanted to get some soft natural light coming in through the blinds that were drawn.

I used a strobe with an umbrella which you can see from the white dot in his eye. He showed last weekend at Amana, IA where he finished his Championship. He's a tad over a year old now.

Thanks for asking me for a post of my dog for they are a dear part of our family and also bed-hogs.

(Download)

Elmerviking

Nice dog! I am an animal over myself...had a really nice Basset Hound, my fav breed!
Now we have a cat, Lizzie, that is the sweetest cat you can imagine. Unfortunately she is hard to photograph.

sippyjug104 Loc: Missouri

Here's "Bud", he's a Champion also, standing on the same table with my same camera setup. This time I had the blinds open but you can see the arm on the grooming table and the lead around his neck holding him still as I take his picture.

(Download)

Elmerviking

Beautiful dog!

Leitz Loc: Solms

I'm disappointed ... you said he'd be using a tripod!

sippyjug104 Loc: Missouri

Oh, now I get it..! Silly me with a play on words. Reminds me of the way some news headlines read like, "POLICE BEGIN CAMPAIGN TO RUN DOWN JAYWALKERS".