What lens is good for jewelry photo ?

<p>Happy New Year to all of you.<br>

I'm learning jewelry photo during the holidays but the DOF from my Nikon 105 macro drives me crazy while shooting a diamond ring. I need to produce a completely sharp picture from diamond to ring. I set to f/16, f/22... with camera on tripod, lighting is good but this 105 macro lens is not able to keep the whole diamond ring sharp from top to bottom when the lens was closed to subject. If I didn't switch to marco and keep 2-3 feet distance between camera and subject, the result was good but I need to crop it. Some articles suggest to use tilt-shift lens. I haven't try it because of the expensive cost. Is there any less expensive DIY to get a sharp diamond ring sample picture ? </p>

<p>Hoi, three suggestions:</p>

<p>(i) Do a search on 'focus stacking'. There are a number of threads and articles on this on photo.net. In the digital age, that's your best bet.</p>

<p>(ii) You might look for a book or websites that deal with macrophography. In general, the fight between depth of field and diffraction is the big central issue when you're shooting 3D macro subjects.</p>

<p>(iii) If you find you need to go the way of a tilting lens, an alternative is to use a tilting bellows. Nikon used to make one and maybe they still do. (I'm not a Nikon user.) Another way to get the same result is to use a thing called a tandem camera, which is a bit of an obscure technique and I won't go into it.</p>

<p>Aside from focus stacking, wider lens like 60mm or manual 58mm would give you more DOF. </p>

<p>Les</p>

<p>Focus stacking is the only way to really achieve this. It is very easy to do with the correct software, of which there are many (just type in Focus Stacking on the web).</p>

<p>Stopping down only helps dof to a very limited extent and comes at the expense of a drastic lowering in resolution and contrast.</p>

<p>Also, any good macro lens will work, but the longer the focal length the more room you'll have for lighting. <br>

For my macro work I use a manual focus 90mm Tamron from the 1980s with the Adaptall 2 mount because it's both very sharp and very inexpensive compared to modern AF lenses. For software I just use the one built in to Photoshop. </p>

Just so this misunderstanding is understood as what it is: a misunderstanding: you do not (!) get more DoF using shorter focal lenght/"wider" lenses, Leszek.<br>DoF depends entirely and exclusively on f-stop and magnification.<br>As long as (in this case) the ring occupies the same space in the frame (i.e. is pictured at the same magnification) switching to a shorter lens will change working distance, perspective (mostly in the background), but, at the same f-stop, not (!) DoF.<br><br>Using a lower in-camera magnification (i.e. larger in-camera DoF) by backing away from the subject, enlarging the resulting image later will not help. Assuming a perfect imaging system, the result will again have the same shallow DoF.<br>In practice however you do indeed get the impression that DoF has improved. But that only because instead of improving the previously out of focus bits you are degrading the bits that were in focus so the difference between them isn't as obvious as it was (which after all is what DoF is).<br><br>Stopping down will increase DoF, but doubling or quadrupling something that is very small to begin woth still leaves us with something rather small. What it (stopping down) will also do is increase the image degrading effect of diffraction, leaving us with still too little DoF and degraded image quality in the parts that were in focus.<br>The secret is (or used to be) not to fight this, not to go in pursuit of something that just isn't there, but to work with it instead. Use the shallow DoF as a compositional tool, or (inversely) compose the image so that the available DoF is used to the max (which is where cameras offering movements and tilting lenses come into play. They too can't increase DoF, but they can position the plane of focus such that the shallow DoF either side of it is used best).<br><br>Focus stacking however is the way out.

<p>To add to what Q.G. wrote: at minimum working distances, all true macro lenses will produce approximately the same magnification (1:1), regardless of their focal length. A shorter focal length will decrease background blur (distinct from DOF), but that won't help solve your problem. (For an explanation of the difference between background blur and DOF, check out http://toothwalker.org/optics/dof.html.)</p>

<p>I do a lot of macro, and I think the only good answer to your problem is focus stacking. There are a number of specialized programs that will stack images. I use Zerene Stacker for this. However, you can stack images in Photoshop without specialized software. if you use photoshop, just google it.</p>

<p>You will need a tripod, and I would add a remote release. A cheap cable release, which you can buy on eBay for $5 or so, is fine. The reason is to keep the successive images well aligned.</p>

To add to what Dan wrote: there are "true macro lenses" and "true macro lenses".<br><br>A true "true macro lens" is a lens that is corrected such that its performance is excellent at the short distances involved in macro photography. Most lenses do rather good at long distances, but perform quite a bit less good when the subject distance gets smaller. Defects that become most visible then are uneven focus across the field of view and lateral colour aberrations (colour fringes).<br><br>To be able to focus close you have to do either (or both) of two things:<br>- Increase the image distance (distance between lens and sensor/film. It the distance between lens and subject decreases the distance between lens and sensor/film must increase to keep a focussed image. From infinity focus to lifesize reproduction, 1:1, the subject distance is larger than the image distance. At 1:1 they are equal (and each equal to twice the focal length of the lens used). Beyond that the subject distance is smaller than the image distance).<br>- Or reduce the focal length of the lens. If the focal length of the lens decreases, a given image distance gets relatively longer, so the lens focuses closer, even though the image distance inabsolute terms has not changed.<br><br>The other "true macro lens" is the sort that does not require extra equipment to achieve half size or full life size reproduction ratio.<br><br>Since most people like it that their lenses can be used to take pictures of small things, many lenses nowadays are capable of focusing rather close without needing any extra equipment. They do that by changing the focal length, which is something they can do anyway because that's the way their focussing mechanism works.<br>Most of these lenses, despite being able to focus rather close, are not (!) "true macro lenses". They are just lenses that focus rather close. (Though sometimes the setting in which they are able to focus close is called "macro", they still do not perfrom particularly well at that setting. It's just a name used for being-able-to-focus-close)<br><br>On the other hand there are true "true macro lenses" that do not focus particularly close without being helped by extension tubes or bellows.<br>Most manufacturers help us distinguish between lenses that happen to focus close and lenses that were made so they have excellent performance when focused close (even though they may need help to do focus close) by "macro" or "micro" (Nikon) designations as part of the lens' name.<br><br>So in short: some lenses that do satisfy Dan's criterium are not really macro lenses after all, while some that don't are. And there a lenses that satisfy both criteria.

<p>I doubt it will help the OP to debate what various people (myself included) mean by a "true macro lens". However, Hoi Kwong, let me try to sort this out in case you are finding it confusing. </p>

 

<blockquote>

<p>The other "true macro lens" is the sort that does not require extra equipment to achieve half size or full life size reproduction ratio.</p>

</blockquote>

<p>That is exactly what I was referring to. I don't consider lenses to that fail to meet that criterion to be real macro lenses, even though manufacturers often misleadingly label relatively close-focusing zooms as "macro." Your 105mm lens does meet this criterion, reaching 1:1 magnification. Mike and Leszek raised the question of whether you would benefit from switching from a 105 (true) macro to another focal length of macro lens that can achieve the same magnification. That's what I was responding to. I was not getting into what you would lose by switching to a lens that is labeled "macro" but can't get that level of magnification. </p>

 

<blockquote>

<p>Most of these lenses, despite being able to focus rather close, are not (!) "true macro lenses". They are just lenses that focus rather close.</p>

</blockquote>

<p>Macro lenses that can attain 1:1 do so precisely by focusing close. Short FL macro lenses have to focus even closer than long FL macro lenses to achieve that degree of magnification. That is why working distance at 1:1 is positively correlated with FL. The lenses that are not "true macro lenses" but that are labeled as macros focus relatively close, but not close enough.</p>

 

<blockquote>

<p>A true "true macro lens" is a lens that is corrected such that its performance is excellent at the short distances involved in macro photography. Most lenses do rather good at long distances, but perform quite a bit less good when the subject distance gets smaller. Defects that become most visible then are uneven focus across the field of view and lateral colour aberrations (colour fringes).</p>

</blockquote>

<p>The principle issue with macro lenses is not deterioration of performance at short distances, although that is important. The primary consideration is that lenses that are not designed as macro lenses simply can't focus closely enough to achieve 1:1 magnification.</p>

<p>So, here is my suggestion of what you should consider:</p>

<p>1. Ignore discussions of different lenses. Your lens should be fine. </p>

<p>2. Try focus stacking. Once you get the hang of it, it is quite simple to do, although a little time-consuming, and it will give you as much depth of field as you want. There are lots of postings on the web explaining how to do it. I will add only two points here. (a) You don't need a focusing rail, or any equipment other than a camera, a tripod, and a remote release. You can create the images you need by making minor changes to the focusing of the lens (manually). (b) Always start by focusing on the closest part of the object and framing accordingly, then move to more distant focus points. The reason is that the framing will change, and if you start at the back end, you may end up with framing that is too tight.</p>

<p>3. Once you are focus stacking, you can use whatever aperture you want. I generally avoid small apertures (large f/stop numbers) to get the sharpest images I can.</p>

 

Dan, i have a number of real macro lenses that require all sorts of help (something to attach them to a camera, such a thing as a lens mount, even) to be able to achieve any kind of macro-range scales, and trust me, they really are true macro lenses.<br>The thing that makes a lens a macro lens is most definitely not that it can focus to 1:1 unaided, but how it performs when you get it there (and beyond).<br>The primary (and quite big) issue is indeed performance. And there's nothing else, really. You can get any lens to do 1:1, but only a few are worth taking there.<br>So yes, there are quite a few true macro lenses that according to your criterium may not be called that, and quite a few that do fullfill your criterium but are not suited for anything closer than a couple of meters. That0s how it is.

<p>Thanks for all advice. I've learned a lot from experts here. <br>

I thought I got the wrong lens to do the job, obviously I was wrong in digital era. Will learn more focus stacking technique to fine tune my learning. <br>

Without the "focus stacking", anything I can do to get deep DoF ? In the summer time, I like to use this 105mm to shoot honey bees, butterflies and bugs. When focusing on their heads or eyes, the rest of picture is blurry. I don't think I can apply "focus stacking" on bugs picture. Any advice ?</p>

<p>In the film era, how photographers shot deep DoF jewelry picture ? Just curiosity. </p>

<p> </p>

<blockquote>

<p>Without the "focus stacking", anything I can do to get deep DoF ? In the summer time, I like to use this 105mm to shoot honey bees, butterflies and bugs. When focusing on their heads or eyes, the rest of picture is blurry. I don't think I can apply "focus stacking" on bugs picture. Any advice ?</p>

 

</blockquote>

<p>There are people who can focus stack bug pictures, but I have never managed to do it. Even with a monopod, I am simply not steady enough. </p>

<p>However, you can get good bug shots without stacking if you are careful. Try to keep the portion of the bug you want in focus close to parallel to the sensor, in order to minimize the needed DOF. Then shoot at f/13 or so.</p>

<p>I'll post a few examples, shot with a 100mm macro lens and no stacking. </p>

<p>with a 36 mm extension tube, f/13:</p>

<p><img src="http://dkoretz.smugmug.com/Bugs/Butterflies-damselflies/i-k3s69PC/1/XL/_MG_7328-XL.jpg" alt="" width="1024" height="715" /></p>

<p>also with a 36 tube, f/13:<br>

<img src="http://dkoretz.smugmug.com/Bugs/Bugs/i-QptwBNb/0/XL/_MG_4659-XL.jpg" alt="" width="1024" height="594" /></p>

<p> </p>

There is no way to make DoF larger besides stopping down. But the gain is minimal, and it comes at a price (diffraction hits, degrading image quality quite visibly, reducing maximal achievable sharpness to half and half again with every two stops you close the diaphragm. Stop the lens down 4 stops, and not only will DoF still be tiny, but the bit that was sharp with the lens wide open no longer is).<br>There used to be no way round this in the days before focal stacking (though slit lighting/scanning techniques were in use. They only work with static subjects. Dead bugs and such). It's how things are, and all you can/could do is work with it, instead of against it.<br>With static subjects, having the ability to reposition the plane of focus using a camera or lens that allows movements also works. That doesn't inctrease DoF, but positions it where it is most useful. You can do more or less the same with a 'static' camera, making sure that most of your subject is parallel to the film/sensor plane. Or use even more elaborate set ups, that for instance combine the projected image of one lens with a real subject, (re-)photographing both. Difficult and a lot of work.<br>With dynamic subjects the trick is to get the important bit of your subject in focus (not in DoF, but in focus), and hope for the best. There's nothing else that can help.

<p>It's easy to overstate the impact of diffraction from a small aperture. In practice, if you are going to print small or especially display on the web, the effects of diffraction on the impression of sharpness are often very small compared to the effects of depth of field. For example, here is one of my very early (unstacked) macro shots of flowers, taken at f/20 with inexpensive gear (a Canon XTi):</p>

<p><img src="http://dkoretz.smugmug.com/Flowers/Flowers-and-mushrooms/i-27QBT9g/0/XL/IMG_2212_8_10-XL.jpg" alt="" width="960" height="768" /></p>

<p>Would the areas of finest detail have sharper detail if I had shot at f/8? Yes. Does it make much of a practical difference? No. A large number of people have looked at this image, and the number who have made negative comments about sharpness is zero. Had I used an aperture like f/11, much of the photo would have been blurry.</p>

<p>So, Hoi Kwong, here is my advice:</p>

<p>--as much as possible, keep the important parts of the bug parallel to the sensor to minimize the needed DOF.<br /> --make sure that the things people will most notice (in particular, the eyes) are in focus.<br /> --feel free to go down to something like f/13 (the actual diffraction limit depends on the sensor, and the optimal aperture also depends on the lens) without worrying. Beyond around f/13, use narrower apertures only if you have to.</p>