Using high F value ( 14 and above)

<p>Hi<br>

I wonder if its useful to use f16 (or More) and shutter speed 1/40 and FX 580ii at +3 ISO 400 or 500 in a large hall with full of people. will the photo be sharp and all the depth of filed will be excellent Or it is not the case (diffraction as mentioned in the landscape cause http://www.photo.net/beginner-photography-questions-forum/00U6mI)?</p>

<p> </p>

<p>Hi. Depends on the lens you are going to use. Wide angle means more DOF where as a telephoto is less DOF. Your probably using a wide to mid-wide and i would guess that f16 would be plenty of DOF. Watch your shutter speed though as you dont want camera shake or subject movement.<br>

goodluck.<br>

Andre</p>

<p>I'd also question whether you actually need all the people in focus. Unless it is a posed group shot, is it that important? Using 1/40th also will bring into play hand holding shake and subject motion issues. And if you are using flash, coverage and flash power available.</p>

<p>Peak aperture is typically f/5.6. f/8 slightly worse than peak, f/11 quite a bit, f/16 useless on DX/APS cameras. On full frame you can work at one stop smaller apertures and get acceptable results.</p>

<p>In practical use, no I don't see it as useful. If I wanted to catch a whole room, I would use a more open aperature to allow more ambient light in and not overly worry about the depth of field so much. Use your preview button and get a feel for the shot. You also need enough light to make those shots work and you want them to look natural. If I was going to shoot that right now I would probably use a 28mm lens or wider and leave it open. Maybe stop to max of 5.6 if I wanted to gain a little dof. Also at f16, the dragged shutter will eventually pick up the ambient light, but you need several big flashes like Lumedynes at about 400ws to through light across a room.</p>

<p>If you got all of the people in a large hall full of people in focus, wouldn't the image be sort of busy and confusing anyways?<br /> <br /> I'm not sure what focal length you are talking about, but even with longer lenses f/8 and f/11 will provide quite a bit of DOF (depending on your working distance). Also, anything above f/11 starts to get you into issues with diffraction.<br /> <br /> Anyways, if you want to know how much DOF you will have given a focal length&aperture, you might pick up a hyperfocal length calculator, or learn to use the hyperfocal length markings on your lens.</p>

<p>DOF is dependent on the focal length of the lens. The shorter the focal length, the greater the DOF at any given aperture. So without explaining which lens you're using it's difficult for anyone to give an accurate answer.</p>

<p>However, you should expect subject movement and handshake at a shutter speed of 1/40. So there's no point shooting a room full of people and hoping for sharpness just because you've got a lot of DOF - the images will be unsharp due to unwanted movement.</p>

<p>You'll get closer to the results you intend if you shoot around f8 and keep shutter speed above 1/250. If your lens is particularly wide you can get significant DOF even shooting wide open.</p>

<p >Yes you will get diffraction at F/16. Whether you see it or not in a print of people in an hall, will be another issue.</p>

<p > </p>

<p >But, no it is not necessary to use F/16 in a large hall full of people, because if we think about it a little, the question is a nonsense . . . </p>

<p > </p>

<p >Let's say we have a large hall and 400 people . . . to get anywhere near the width to accommodate those people in frame we would need about a 28mm lens on a 135 format ("Full Frame") or about 17mm for a APS-C camera.</p>

<p > </p>

<p >With a 28 on a 5D we get about 10ft to infinity at F/5.6</p>

<p >With a 17 on a 20D we get better than 10ft to infinity at F/4</p>

<p > </p>

<p >WW</p>

 

<p>you are getting diffraction at anything over f11.0 on a c sensor dslr, let alone f14.0. for myself i try not to go above f11 unless it is absolutely neeeded. suggest you give some thought into studying dof tables with various lenses and apertures. see-<br>

<a href="http://www.dofmaster.com/dofjs.html">http://www.dofmaster.com/dofjs.html</a><br>

i think you will find that excessive fstops just are not needed. in the case that you stated shooting a hall full of people it is not a matter of fstops, it is a matter vof having a wideanagle lens wide enough to do the job. and when you use a wide angle lens say a 20 or 24mm lens you will be getting lots of dof at any fstop. also, the lens performance at the ends of the range, that is f1.4 or f16, are just not as good or even close to the max performance fstops. the best sharpness and performance of any lens is going to be somewhere in the f5.6 to f11.0 range. the sharpest fstop will also be in that range somewhere. at f1.4 you let a lot of light through but the lens is just not as sharp as the good range. at f16 you get a lot of dof but you pay for it with diffraction and a lack of sharpness.</p>

<p>One vote for "wouldn't never ever..." no reason I can see to do it :-) IMHO</p>

<p>hi all<br>

I apologize for ot replying because i had internet problem for the last two weeks. I also want to thank all of you for your help.</p>

<p>Actully im using canon lense 24-70. I hope that can help you to give me more deatiled answers. I also attached two photos so you can tell me what are the best settings for this kind of photos</p>

<p><a href="http://www2.0zz0.com/2009/07/21/22/739455853.jpg" target="_blank">http://www2.0zz0.com/2009/07/21/22/739455853.jpg</a><br>

<a href="http://www2.0zz0.com/2009/07/21/22/820919032.jpg">http://www2.0zz0.com/2009/07/21/22/820919032.jpg</a></p>

<p>thanks in advance</p>

<p>I'm with Ilkka on this one, the DOF goes up, but the quality down after 5.6/8.<br>

have you checked the difference between f8 DOF vs f16 softness? The answer might be in there.</p>

 

<p><strong><em>"Actully im using canon lense 24-70. I hope that can help you to give me more deatiled answers. I also attached two photos so you can tell me what are the best settings for this kind of photos"</em></strong><br>

<br>

In general terms:<br>

<br>

1. You use the lens at the wide - 24mm. If those two images were taken at 24mm then it seems to me you must have an APS-C camera (like a 20D 30D 40D etc) and not a 5D . . . in fact they look like you are not even at 24mm on an APS-C body.<br>

<br>

2. You need to understand and know some fundamental DoF (Depth of Field) parameters: I think the first one you should commit your memory is: <strong ><em >“24mm on a 20D is 12ft at F/8"</em></strong> . . . <br>

(the 20D is my camera - if you have a 30D, 40D, 50D etc then the rule is the same)<br>

<br>

The rule means: If you focus on a subject at 12 ft (or a little farther away) you will be pretty sharp from about 8ft to infinity (actually a bit closer than 8ft - but I like to have some margin for error).<br>

<br>

3. Now you know that basic rule, then next issue you need to ensure is that the closest subject is 8ft away from you.<br>

<br>

*** <br>

<br>

This topic of DoF comes up frequently and I reiterate that a DoF Calculator or DoF wheel is a really handy piece of equipment - but it really is not that difficult to commit to memory some standard distances and F/stops for three or four Focal Lengths. <br>

<br>

WW</p>

<p>Addendum: My apologies - I do not instinctively do metric measure - if you are metric, you might like to learn:<br /><br /><strong><em>"24mm on a 20D is 4mtrs at F/8"</em></strong> . . . and your closest subject can be at 3 mtrs.<br>

<br />WW</p>

<p><a href="../photodb/user?user_id=487798">Daniel P</a>,<br>

I will make the try and will compare the softness.</p>

<p>William w,<br>

Thanks for explaing the rule. Yeah, I have 40D. I will use f8 with 24. But what about the lighting? Will I get a good exposure if I use ISO 400 and shutter 60 and flash +2/3? Note that most of the weddings are in the same hall ( same as the previous photos).</p>

<p>I got the DOF table (for 40D) but i didnt know how to use it (<a href="http://dofmaster.com/doftable.html">http://dofmaster.com/doftable.html</a>)? Can you pleas expain to me how to use it?</p>

<p>Thanks in advance</p>

<p> </p>

 

<p >When combining Flash and Ambient Light no-one can say whether your exposure will be correct or not - as we do not do not know the EV of the Ambient Light in the hall.</p>

<p > </p>

<p >However we can have a starting point - and I would generally choose a faster shutter speed than 1/60s in most Flash + Ambient situations because I would like to ensure that I did not capture any subject movement. I would like no slower than 1/125s, generally.</p>

<p > </p>

<p >Also the Flash Compensation you use depends upon the Ambient EV and to some extent the Flash Modifier (or not) you use and the “harshness” of the Flash’s impact you want, in the final image.</p>

<p > </p>

<p >Note also that <em><strong>“24mm on a 20D is 12ft at F/8" </strong></em>is just my rule not something you should do all the time. . . I just learnt some key DoF for a few specific Focal Lengths - basically the Hyperfocal Distances, to use for large groups such as this situation; and I also committed to memory some DoF for F/2.8 and F/4 at a few different distances, and Focal Lengths, for use when I want to go very shallow DoF.</p>

<p > <br>

WW</p>

<p>thanks a lot William w. I have a wedding after two days and I will try it.</p>