Guessing which aperture to use - bit stuck.

[Ian Rance]

<p>Being an enthusiastic photographer I enjoy spending time out with my camera, however yesterday I realised that I did not know as much as I thought. I am fairly good with landscape and portrait, but now I have a macro lens I am stumped. I realise that this is a complex subject, so I don't expect a detailed answer - just a little guidance to get me started.</p>

<p>My Nikon 55mm macro lens has DOF markings, but these stop after the lens is focused closer. I was taking some photos of some wonderful fungi and flowers, but when the lens was around 1:4 - 1:2 magnification I had no idea what aperture to set to get my flower head or small mushroom in clear focus front to back. I know that macro lenses become slower at close distances, so I added one stop to what was on the scale. I tried the DOF preview, but what with the low angle and dark viewfinder all I got was a serious cramp. On my previous macro effort, I remember seeing that whilst it may look in focus down the viewfinder, what you get back often has less clarity than what was down the finder - less DOF.</p>

<p>I tried f/8, f/16 and f/32 but I was only guessing - and that is never the way forward. Since macro shots at close range are so variable in shape and size, I was wondering if there was some known formula like always use f/22 at close range or something similar....</p>

<p>I am aware that experience probably also very important, but for every 36 photos I take, the charge is $10 so experience does not come without a price. Sadly I am not in a position to just keep paying for photos as money is a bit tight at the moment.</p>

<p>Thank you for any guidance,</p>

<p>Ian</p>

[mike dixon]

<p>At such distances/magnifications, DOF is extremely shallow, even if you stop down to f/32. Unless your subject is only a tenth of an inch thick, it may not be possible to get sharp focus from front to back. Here's a DOF calculator to give you the specific data:</p>

<p>http://www.dofmaster.com/dofjs.html</p>

[Ian Rance]

<p>Thanks Mike - that is very useful!</p>

<p>I have worked out that it is <strong>only 1"</strong> even at f/32! I think that my photos from yesterday will be scrap at that rate - but now at least I know for next time. On reflection I think I will leave macro to the experts who know what they are doing.</p>

<p>Ian</p>

[waltflanagan]

<p>I guess you aren't using digital. Are you using a tripod?</p>

[Ian Rance]

<p>Walt, yes I am using a good solid tripod, cable release and MLU. The lens is the 55mm f/3.5 P.C. No, I am not using digital as I do photography for mostly hobby reasons.</p>

[waltflanagan]

<p>You will get more in focus at f22 and f32 but the image will be softer because of diffraction. I've used the DOF preview for decades and found it worked well for me. If you're at a bad angle you could see if there is a right angle viewfinder for your camera. I've found my best macro shots were when I wasn't afraid to get dirty. Lay on the ground if necessary. Sometimes it is impossible to get everything you want in focus even at f32. Today people shooting digital use focus stacking software. They take multiple pics with a different focus and software merges together the sharp parts of each image.</p>

[matthew_newton]

<p>I'll throw in with Walt, sometimes you just need to get down on the ground and dirty. I use the DOF preview button extensively with my 50/2.8 macro. A tripod is also critical. I was taking some orchid pictures of my mother-in-law's flower over Easter for her and I probably spent 15-20 minutes taking the pictures between deciding on composition, setup, taking them etc. I do wish I had taken my flash with me so I could have better controlled the background and lighting, but alas natural (and tungsten) lighting was all I had to work with. I also use film, so sometimes it is a little frustrating to see how the picture actually turned out. Practice makes perfect however. After you take a few rolls you get used to what the results are likely to be. I rarely use beyond f/16 even at 1:1 (sometimes to f/22 which is as far as my lens goes). I notice a very slight softening at f/22, but nothing to noticable unless its a big englargement.<br />I know that magnification is the primary ingredient in DOF, but a wide angle lens can help out as things a little behind your point of focus are at lower magnification then if you were using a longer focal length lens. I don't have any back to back images taken with my two lenses, but my Sigma 24mm f/2.8 which can go to 1:4 can deffinitely get more in focus at the same f-stop as my Sigma 50mm f/2.8 macro at the same magnification. Of course at something like 1:1 or 1:2 that might not be nearly true. It could just be you don't have enough aperature to get the whole thing in focus, in which case it is impossible without focus stacking. One option though is to try different compositions. If the mushroom is wide but the head isn't very tall, you could always go for more of a top down picture or vice versa if it is tall but not wide.</p>

[matthew_newton]

<p>Example pictures.</p><div></div>

[matthew_newton]

<p>An example of just how shallow DOF is at 1:1 (worse then 1:2 certainly).</p><div></div>

[Ian Rance]

<p>Thanks Matthew and Walt,</p>

<p>I will wait and see how my photos turn out - waiting is part of the fun - sometimes they 'come out' better than I thought they would, but sometimes worse. I will share anyway. In a chapter about macro I also read about wide angle lenses being used but by the sounds of things this may be better to use than a proper macro lens. I see that there are 100 and 200mm macro lenses available also - if I am struggling with my 55mm the longer lenses will be worse still I think.</p>

<p>Ian</p>

[david_barts2]

<p>In macro photography, one typically has to pick which part of the shot is to be in truly sharp focus and let the rest fall where it may. The trick is to get that sharp part of the photo eye-catching enough that it ends up being what the viewer pays the enough attention to that s/he really doesn't notice (or isn't bothered by) the rest of the subject being blurred to various degrees.</p>

<p>Regarding this:</p>

<blockquote>

<p>I see that there are 100 and 200mm macro lenses available also - if I am struggling with my 55mm the longer lenses will be worse still I think.</p>

</blockquote>

<p>Not necessarily. A 55mm lens has its own set of frustrations. At 1:1, you're so close to the subject that it's often difficult to shoot it without touching some part of the same plant and making it move (or casting a shadow on the subject). Longer lenses let one back off and avoid these problems.</p>

<p>A longer lens also includes less background, thanks to its narrower angle of view, which can mean for fewer distracting elements in the shot. And narrow DOF can sometimes be useful for the same reason (blurs background distractions away)<br /> .</p>

[k5083]

In photography as in most arts, guessing (experimentation) actually IS the way forward.

[t37traveler]

<p>I I learned macro shooting underwater photography. In that theater macro is referred to as the "no brainer point and shoot" method. Flash is set for TTL; aperture is set for max (f/22 or higher). You want the to use greatest depth of field you can dial in and rely upon the flash for lighting the subject. That dof is going to be pretty narrow - the closer the lens is to the subject (and it's max. minimum focus) - if that makes any sense, the narrower that dof will be.</p>

[Ian Rance]

<p>Thank you for the advice and comments.</p>

<p>Ian</p>