stephen_van_egmond1

<p>Yes - I understand that any camera that has an MF/AF switch can work with trap focus.</p>

<p>I would bet any lens that has quick-shift focus can work with trap focus as well. That's the one where you can change the focus once the lens gets focus.</p>

<p>Further research bears this out: you can only trap focus if you turn your lens into a manual, possibly with a switch, or cover the contacts on the lens/camera. I gather there's one magic one ("DATA") but I forget which one that is.<br>

How silly.</p>

<p>Hi folks,<br /> Mundane how-to question here.<br /> I'm not certain, but I was *positive* this was easier with the k10d.<br /> I simply want to use catch-in focus with an autofocus lens. The current way I do it with a manual lens is:</p>

<ol>

<li>Set focus switch to AF-S</li>

<li>Turn on the custom control setting to enable catch-in focus.</li>

<li>Point camera at subject</li>

<li>Push shutter release all the way</li>

<li>Turn focus ring until subject's in focus, bam, shot taken.</li>

</ol>

<p>This *only* works with manual lenses. If I want to do this with a modern lens, I have to tape over the lens's contacts, or put some tissue between the camera and lens when I mount in the lens. There has to be a better way. The "M" focus setting is the obvious route.<br>

<br /> I'm working with a K-7 and Pentax-FA 100mm 2.8 macro at the moment, but really, this applies to any modern lens.</p>

<p>Another comment in loving praise of the Pentax build quality: My K10d tumbled out of a car and onto concrete pavement. It took it on the shoulder up by the shutter release.</p>

<p>Everything remains 100% A-OK, just a scuff on the rubber skin of the body.</p>

 

<p>The nature of in-body image stabilization is such that it is less useful as the lens gets longer, simply because the same slight movement requires more range of movement than the sensor can provide.</p>

<p>With 400 or 500mm lenses you might as well have it off, in my view.</p>

<p>Pentax says to turn SR off when on a tripod. In my experience this is exactly right. If I get a lousy shot on a tripod, it's usually because I left image stabilization on. I have absolutely no idea why this is the case, but it is.</p>

<p> </p>

<p>I have a DA21 and I think it's a splendid lens. You should consider it.<br>

When I'm not sure about a focal length, and if it's for me, I usually buy a manual-focus version for cheap on craigslist, and see how it suits me, and then buy the best lens I can afford when I'm sure it's right. This saved me from buying with a nonexistent good 135mm or hugely expensive 60-250 zoom.<br>

I own a DA14 and I would trade it for a DA15 in a heartbeat. Not that it's a bad lens, it's just so ... incredibly ... huge.</p>

<p>Jeff-<br /> Don't think that you need to master all those tools to achieve the same level of success in digital photography. I personally use Aperture, and though it has all the fiddly noise reduction and colour twiddling settings anyone would want, I prefer to limit myself to what can be pulled off in a dark room: cropping, straightening, exposure tweaks, and converting colour to B+W.</p>

<p>Rather than master a piece of software I prefer to master the camera. I spend all day writing software for a living and photography is my reason to get outdoors. I prefer to do only the minimum necessary to my shots. I find I like the authenticity.</p>

<p>No disrespect to the lightroom masters, though. John, I would be very interested to see what your splendid portrait looked like when it came out of the camera.</p>

<p>To the original poster, you don't have to "believe" in any given system, just find the one that works for you. Understand that a bug in a particular equipment combination is not a systemic fault. To your particular problem, I can't shake the feeling that your setup is slightly front-focusing. Ever so slightly. This slight tendency is magnified by your habit of shooting at wide apertures with relatively long lenses, which produces very narrow focus planes. This is not a systemic fault, any other camera will produce the same result.</p>

<p>Play with the widget at the bottom of http://www.bobatkins.com/photography/technical/dofcalc.html . For instance, a subject 5 feet away at f/2.8 on a 105mm zoom has a 1 inch wide depth of field. 7 feet away? 3 inches. In such a situation, you must nail the focus, and hope that the composition still works with everything outside your DOF plane fuzzy.</p>

<p>I have this lens, and if I point it down it does not creep downwards, but pointed upwards it will retract about halfway from 70. It does have a button that will lock it at 17. Zoom creep has never been a problem for me.</p>

<p>I don't think this lens is noticeably better than the 18-55, mind you. It's just another cheap zoom with varying aperture. I would have been happier with the 16-45 f4 or the DA* 16-50. My bias is to buying the best lenses you can afford, and this Sigma is a clear disappointment. I never like using it. </p>

<p>If your budget is tight, consider getting a used K10D. I'm still pleased with mine.</p>

 

Arrrgh. So many complaints about the lack of wide aperture on this lens. If this is regarding low light shooting... the stop might help. But

DOF? Doesn't matter. Just look at the DOF markings: http://www.photokina-show.com/news_images/0604_pentax-15mm.jpg

<p/>

 

The focus markings go from infinity, to 0.5m quickly, and then taper slowly to 0.3m off for the rest of the way around the focus range.

<p/>

 

As a result, f/4 or f/2.8 is already absurdly narrow DOF (if it's close up) or most of the way out to inifinity (if it's more than a meter away).

You will rarely get interesting DOF effects out of a DA14 or DA15 limited, unless you're grinding your front element into your subject.

<p/>

 

So relax and use f/8, you'll enjoy the lens.

<p>Kathy-</p>

<p>Thank you very much for the sample images. Looks nice. Are you able to squeeze any depth of field effects out of that lens?</p>

<p>To my eyes, the uncorrected kitchen photo looks better. The corrected one makes everything look like it's had a run-in with a truck. Perspective distortion is inevitable with a lens that wide; try taking a person's portrait, and see how huge their nose is.</p>

<p>What is usually termed distortion is barrel or pincushion distortion, which can best be seen by taking a photo head-on of something with strong verticlal and horizontal lines, and observing how the lines weave across the frame. This usually ends up being a brick wall. However if you're taking pictures of a brick wall, you probably should be doing something else. I do it once with each lens I buy to see if I got a lemon and so I know what to expect when shooting architecture. It's generally not worth fussing about, at least with primes.</p>

 

<p>At 15mm you need a pretty contrived scene to get any bokeh at all. The difference f2.8 to f4 is trivial. The other rationale would be fast shutter in low light -- but for me anyway, a wide-angle lens only gets play outdoors during the day or sunset, when I'm in the f4-f8 range anyway.</p>

<p>Frankly, I would trade my 14mm 2.8 for a 15mm f4 in a heartbeat. If anyone who lives in Toronto wants to trade, drop me a line :)</p>

<p> </p>

<p>Since you're shooting with strobes, aperture is not really an issue unless you really care about depth of field... but that's a pretty unusual portrature style.</p>

<p>Any of the FA50 lenses will be fine. I have a f1.7 and it's great, and cheap. The suggestions for 70mm to me sound like they're too long, but may be appropriate for just babies.</p>

<p>My suggestion, get a cheaper prime, manual focus even, because you'll be shooting at F8 anyway any slight focus errors won't matter. Then spend more money on lighting.</p>

<p>I've done some product photography for the food packaging industry, and have turned down a job shooting light fixtures for a local store. I have absolutely no idea how to do that kind of thing, and at the time was busy enough that I didn't have an inclination to learn. I kind of regret turning it down.</p>

<p>Generally the photographer shoots what the designer needs, the designer either working for the client or being accountable to them. What does your customer want? A picture of a guitar? He's got one. I'd trade the pixels of the mirror image for more pixels of guitar but then, I'm pretty flat-footed as a visual designer.<br>

There is a very good series of articles at http://www.photo.net/learn/photography-business/freelance-photography-advice/ to walk you through the business end. I'm concerned you're doing the creative direction, graphic design and photography.</p>

<p>I'm ignorant of what matters on a guitar, and I would probably just shoot the interesting-looking bits and pieces. I'm sure the client could tell you what a person would actually need to see to make a purchase decision. Although the bottom-perspective shot is interesting, it's not informative.</p>

<p>All that said, you're shooting musical instruments to musical people. If this is being presented on a web site, my personal advice would be to forgo agonizing over product shots and spend somet time recording the instruments and offering sound samples - THIS IS HOW SEXY YOU'RE GOING TO SOUND WHEN YOU PLAY THIS THING. (No Stairway to Heaven allowed.)</p>

<p>$.02.</p>

<p>I've done some product photography for the food packaging industry, and have turned down a job shooting light fixtures for a local store. I have absolutely no idea how to do that kind of thing, and at the time was busy enough that I didn't have an inclination to learn. I kind of regret turning it down.</p>

<p>Generally the photographer shoots what the designer needs, the designer either working for the client or being accountable to them. What does your customer want? A picture of a guitar? He's got one. I'd trade the pixels of the mirror image for more pixels of guitar but then, I'm pretty flat-footed as a visual designer.<br>

There is a very good series of articles at http://www.photo.net/learn/photography-business/freelance-photography-advice/ to walk you through the business end. I'm concerned you're doing the creative direction, graphic design and photography.</p>

<p>I'm ignorant of what matters on a guitar, and I would probably just shoot the interesting-looking bits and pieces. I'm sure the client could tell you what a person would actually need to see to make a purchase decision. Although the bottom-perspective shot is interesting, it's not informative.</p>

<p>All that said, you're shooting musical instruments to musical people. If this is being presented on a web site, my personal advice would be to forgo agonizing over product shots and spend somet time recording the instruments and offering sound samples - THIS IS HOW SEXY YOU'RE GOING TO SOUND WHEN YOU PLAY THIS THING. (No Stairway to Heaven allowed.)</p>

<p>$.02.</p>

<p>last one</p><div></div>

<p>more..</p><div></div>

<p>Hi,<br>

I think this is my first time contributing to PoW. I just came off a trip to St. Lucia with some friends. The local economy is based around bananas and tourism; if they think you have money they will try to rob you blind. I think world economic problems are hitting them hard, as they aim at the higher end of the all-inclusive resort crowd. We stayed in a house on one of their iconic pitons and drove ourselves around. The locals speak an utterly incomprehensible patois of french, english, carib, and various african languages drawn from the slaves that were imported in the 17-1800s.<br>

For such a lush island the produce in the markets was astoundingly bad. We had to barter with a restaurant's kitchen staff to get a shrunken pineapple. I guess the good stuff gets exported.<br>

All photos K10D and either a DA21 or D-FA 100mm macro.</p><div></div>

<p>Folks,<br /> I own a DA14/2.8. It's a fine lens and built well.<br>

<br /> Comapred to the 15mm it's a monster. The edge of the lens causes the camera to be unable to sit flat on a table. I can't imagine how huge it would be as an f1.4. The comparison to Canon's 24mm 1.8 is not reasonable; things get really big really fast at the wide end.<br>

It's worth asking yourself what the difference is f2.8 to f4.<br /> From the DoF markings on that lens, it will provide adequate range in that department, but bear in mind that the focus point very quickly zooms from 1 meter to infinity. Check out the markings on the picture above. The DA14 is similar.<br>

<br /> The only other reason is low-light performance, which is really in the eye of the beholder. I'd trade my DA14 for a DA*15 in no time, owing to its really huge size.</p>

<p>It doesn't seem to me that a DSLR is a good interface for shooting video. Most video cameras have a cluster of controls under your fingers, and several things to grab and fiddle with on your stabilizing hand. Clicky buttons and dials are a complete nonstarter.<br>

That said, if you have seen the Depth of Field adapters that you can attach to good consumer cameras like the canon HV20 or HV30? You can bolt on a Pentax K, Pentax M42, Canon or Nikon lens (including the ones that their advances have orphaned) and get really incredible output. e.g. the latter half of

or http://vimeo.com/1290326 .<br>

However if you've ever seen one of these adapters they're ridiculous contraptions. The 35mm lens focuses the scene onto a piece of etched glass that a motor SPINS or vibrates to hide dust or imperfections, and the camera focuses and films that. There's all kinds of extra gears and gadgets and rails to get focus to work. Clearly room for improvement.</p>

 

<p>From my research, you're right. And here I was thinking F lenses would be the most annoying in the world to use!<br>

Conversely, though, "A" lenses do follow that lettering scheme. "A" lenses let you control aperture, but do not auto-focus.</p>

<p>Nick-<br>

You may well be right. I've never used an F lens.</p>

 

<p>Debi-<br /> To summarize the differences:<br /> - The first lens is F whereas the second is FA. One allows the camera to control focus and not aperture, whereas the other allows the camera to control focus + aperture. In the first case you have to pick aperture for what you're shooting, and use your camera's controls to meter it (doable, but work).<br /> - The firs lens is f1.7 whereas the second is f2.8. This buys you two things on the first over the second: first, it works better in low light; second, the focus plane is narrower which means that if you open it all the way up you will blow out the background into out of focus, which we geeks term bokeh.<br /> - The second lens is macro which means you can focus it way closer than the first, and more likely, that it will be (a) heaver and (b) more sharp no matter what situation you put it in. The comparitive pictures someone else posted show this size to performance tradeoff.<br /> They both are reasonable lenses. If I had to buy one it would be the macro.</p>

<p>I don't know who these people are that don't like that lens. It's one of my favourites.</p>

<p>I posed a gallery of some photos I found lying around in Aperture at http://svan.ca/photos/pentax-dfa-100mm/ .�<br /> There's about 75 of them, not very many macro, mainly drawn from a food festival held in the fall. I didn't edit or crop or manipulate them. Heck, there's even one with the lens cap on. Still, gives you an idea of how the lens performs outside of macro.<br>

<br /> Features a photo essay of all the people wearing rubber boots on a dry day!</p>

<p>Certainly it's useable! "Macro" is an addition to regular lens operation, not a subtraction.<br>

I have a DFA 100, and would be happy to take a few example shots to show you what it's like.<br>

Is there any particular style you want to try with it? Mine rarely spends time focused any further than 6 feet. What kind of subjects would you like to see to help you make the choice?<br>

It certainly focuses all the way out to infinity and has a pretty narrow depth of field for its size. The field of view would let you take a picture of a two-person interaction across a street.</p>

 

<p>Pentax made a great move by providing such a good kit lens. Rather than annoy you into upgrading it right away, it performs well in typical new-photographer scenarios. You can take good daytime pictures, and it will do something reasonable in an evening shot with the flash on..<br /> <br /> Experienced photographers might turn up their noses at the slightly loose-feeling plastic construction. However: the construction is fine where it counts, it just doesn't *feel* expensive.</p>

<p>Experienced photographers might also turn up their noses at the modest aperture range. However: I don't think many people who just upgraded off a P&S even know what aperture is and what it does and why they should care.<br /> <br /> In the meantime until they get around to caring about these things (that spells LBA, folks) it takes good pictures and doesn't weigh a ton. I almost miss it. My Sigma 17-70 is a weighty monster in comparison and doesn't take appreciably better photos.</p>

<p>That looks like sunset or a far-north late afternoon. ISO 400-800 would have been a good choice. ISO 100 is for broad daylight or courage.<br>

Don't forget to turn off SR when it's on the tripod. I have no idea why that scenario goes sideways, but it does.<br>

The point about depth of focus field is right on too - look at the bird photo, notice the focus is on the eyes, but the beak and the back 70% of the wings are out of focus.</p>