FAST LENS

<p>Will you please give me some advice?<br>

I'm considering buying a used 1.4 85 mm lens because I like doing night photography of people - individuals more than groups. How big a help is that extra (half?) stop from 1.8? Does the image also appear brighter in the viewfinder to allow an easier time of focusing? I've noticed previously that a picture I take at a given f/stop with my Nikon 80-200 mm f/2.8 turns out brighter than one I've taken with my Tamron f/2.8 28-105 done at the same f/stop. Will I get the same advantage with a 1.4? Will it be even more than I might get from the 1.8? <br>

I use a D700 Nikon. How much better will a Nikon or Zeiss serve me than some other?<br>

I focus manually, so a manual focus lens is just fine. Also, how difficult is it to get a person in focus if I ever have to stop down so low?</p>

<p>That half stop doesn't make much difference in low light; the main reason for the 85 f/1.4 lenses is that their designs are optimised for a pleasant, smooth out of focus rendering and they tend to be better at wider apertures - at a significant price. If portraits are your bread and butter, then by all means, do save up for one of the f/1.4 versions (the Nikkors), as they are really good. But if it is for the occassional portrait, or mainly to gain half a stop of light in low light, the value for money gets a bit problematic.<br>

If you currently own the 85 f/1.8D, then there is a point to be made for the f/1.8G version, which seems much improved at wide apertures. If you already have this recent G-version, than the upgrade to one of the f/1.4 lenses will not be as significant.<br>

<br />The D700 viewfinder seems optimised for f/2.8; I do not see significant differences in brightness when using a f/1.4 lens versus a f/2.5 lens. So for manual focus no huge improvements going from f/1.8 to f/1.4 either.</p>

<p> </p>

<p>Thank you, Wouter.<br>

I assume I'll use the 1.4 (or 1.8) very often - inside and out - especially in the studio, but as I said, it's my increased interest in night photography that has me searching.<br>

What about the issue of even being able to get my subjects sharp at such a low f/stop? I've been practicing by shooting as much as possible at 2.8. The margin of error is pretty slim. I saw another Photo.net comment elsewhere from someone who pointed out that while you might get the eyes very sharp, the person's nose might be blurry. Is that a common problem?</p>

<p>Well, a common problem for sure - it's how things work: depth of field decreases as you use wider apertures. If you want to get your entire subject sharp, you need to stop down (f/4-f/5.6 probably at normal working distances), at which point most advantages of a f/1.4 lens are nullified. Most people get these lenses because they want to use the tiny depth of field - despite being harder to focus and get it right.</p>

<p>I fear extremely fast portrait lenses are of little help in general on 35mm bodies. - To me they seem a nightmare to focus manually and the DSLR screens surely don't help with that chore. If you are aiming for a portrait, the absence of DOF is really hard to handle.- i.e. I needed an extra back and forth cycle after realizing "ooops I should have noticed the front eye in focus a few degrees ago".<br>

- FTR: I was used to Tamron 90mm f2.3 on Pentax and given 85mm f1.4 on Nikon and a f1.5 on Practica (manual film bodies), played around and returned them happily knowing they aren't my cup of tea. <br>

If I am ever going for a fast people lens, it might be the 42.5mm Nocticron on a capable MFT body, until then I'll continue dabbling with a 50mm f1.4 on APS-C as fastest and f2 stuff on FF.</p>

<p>You will have some dof issues if shooting wide open. Not only will your dof be very shallow at 1.4 but your critical focus will have to be exact. Studio portraiture isn't sports but subject movement can cause oof issues. Also, the main reason aside from the ability to capture in lower light and bokeh is that lenses are sharpest stopped down 1-2 stops from maximum aperture. So if you need maximum sharpness in your subject, you will accomplish that at wider aperture with fast glass than with consumer grade lenses. A 1.4 lens will give you better quality at 2.8 than a 2.8 lens at 2.8 and so on. Most modern DSLR's can yield better results at higher ISO than was typical with film or earlier dslrs, making extremely fast lenses for low light much less important, but still the ability to really create a smooth, buttery bokeh (which is lens dependent) requires an open aperture. If you want a nice portrait lens consider the DC 105 or 135 options which allow you to select your own level of shaprness.</p>

<p>A DC 105 or 135, Mark? I must confess I'm not familiar with those. But, wouldn't I always want maximum sharpness, or are you referring to background sharpness/bokeh? Can you give me a brief summary on those, please?</p>

 

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<p>I'm considering buying a used 1.4 85 mm lens because I like doing <strong>night photography of people</strong> - individuals more than groups. . . Also, how difficult is it to get a person in focus if I ever have to stop down so low?</p>

</blockquote>

<p>If your question also means: “I like the FRAMING that I get using an 85mm lens for individual portraiture” – then seriously consider buying a very fast 50mm lens; stand at the same Camera Viewpoint as you would if you were to use an 85mm lens (i.e. you will be FRAMING looser but you will maintain the same PERSPECTIVE) - then crop tighter in post-production.</p>

<p>This technique allows a little crib room apropos DoF and also Accurate Focus.</p>

<p>***</p>

<p>The practical, real world useful difference between F/1.4 and F/1.8 in regard to final shutter speed and DoF is almost nil, it only matters when one is at the limit of acceptable ISO -AND- at the limit of acceptable Shutter Speed - and it is rare nowadays to get to the limit of acceptable Shutter Speed, because, as already mentioned, most modern DSLRs get acceptable results at very high ISO levels.</p>

<p>WW </p>

 

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<p>I saw another Photo.net comment elsewhere from someone who pointed out that while you might get the eyes very sharp, the person's nose might be blurry. Is that a common problem?</p>

</blockquote>

<p>Depends how tight you frame the shot (i.e. your Distance from Camera to the Subject) – it is just Mathematics. The DoF is very slim for an Head Shot, I don’t like to frame much tighter than this with an 85mm lens for exactly that reason of acceptable DoF:</p>

<p><a href="/photo/10963088&size=lg">http://www.photo.net/photo/10963088&size=lg</a></p>

<p>If I want a tighter result and am shooting in situ and available light, then I usually use a 50mm Prime with the technique I described above:</p>

<p><a href="/photo/16818012&size=lg">http://www.photo.net/photo/16818012&size=lg</a></p>

<p>WW<br>

</p>

<p>I think the whole ' the 1.4/85mm is soft' thing is a wildly exaggerated story only too often based on the all too notorious internet expertise of non users 'who read about it on the internet' rather their personal experience.</p>

<p>For one, lenses like the 1.4/85 and 2/135mm DC (and not to forget 2/200) have ridiculous shallow DoF when used wide open (If used several stops closed down as a standard, I personally see no advantage in buying a more expensive 1.4 lens when there also is an excellent 1.8 alternative available). So consequently high demand is put on proper shooting technique, AF calibration, and correct (= fast enough) shutterspeeds.<br /> With the 2/200 VR the latter isn't too much of an issue, since common sense (and bulk and weight of the lens) already dictates using higher shutterspeeds ( as well as use of a tripod or monopod), and it has VR to compensate for possible camera shake. The 85 and 135 on the other hand don't have VR, so when used with too slow shuttterspeeds will show unsharpness due to camera shake, a deadly combination with the shallow DoF.<br /> <br />With a fast enough shutterspeed and proper AF technique the 1.4/85 (in my case the 'old' D version)will proof just as sharp as eg the 2/200 VR<br /> 1.4/85mm D : http://www.pbase.com/paul_k/image/145046624/original<br /> 2/200 VR : http://www.pbase.com/paul_k/image/127482300<br /> That said, I think using a 1.4/85 or 2/135mm DC will prove quite a challenge to shoot wide open manually (I have both) and when used in that way a fair number of OoF shots should be taken into account due to simple physics (holding a body with a heavy lens still while at the same time trying to keep the AF field on the selected area, and simultaneously turning the focusing ring).</p>

<p>It's not limited to these kind of lenses though, I e.g. have a 2.2/85mm Petzval lens (Lomography edition). When you do a search on the internet you'll find many complaints about the sharpness of that lens ( and pictures to 'proof' that).<br /> Yet when used at a sensibly high shutterspeed and proper support (the gear rack focusing system makes it in my experience close to handhold the camera still and at the same time get a sharp picture when used at the max aperture of 2.2) it can even when not using a tripod (something I generally speaking stopped doing literally decades ago) give a result that (as far as sharpness in the area focuses upon is concerned) easily matches that of more modern lenses http://www.pbase.com/paul_k/image/156857557 .</p>

<p>If you really want to shoot subjects under bad light with your lens wide open however, in my experience the most important thing no matter whether you use a 1.4 or 1.8 lens (using an AF camera) is that the AF callibration is 100%, and the AF of the camera is up to shooting under bad (which usually translates in low contrast) light so you can trust the 'in focus' confirmation of the camera (just like you would rely on the hopefully sharp image on your focusing screen in the film shooting days).<br /> Yet it still is/can be a major improvement over shooting manual (e.g. compared to my F2AS shooting days using a with a K-type focusing screen, which would simply blacken out under bad light).</p>

<p>Mastering fast lenses wide open takes practice. For example, 135 mm at 2.0 gives less than a half inch dof. I usually stop down to get both eyes sharp if they aren't on the same plane. I hope you are spot focusing on the eye you want in focus. Not only subject movement back and forth, photographer movement back and forth can easily exceed that half inch. Tipping the camera excessively to re compose after locking focus changes the distance as well. Good idea to move the focus point so minimum recomposition movement. I don't manually focus in that range, I get great results from my autofocus. The difference between the 1.8 and 1.4 is more than just a half stop, its image quality. Here is an event grab shot at 1.4 with the Nikon 85g on camera flash bounced off dark wood panel walls in a narrow entry with the Christmas tree in background. Both eyes on same plane, eyes in, ears out of focus. I am more worried about my lighting, posing and background that some pixel peeping lens difference. However, if at wide aperture, those tree lights were octagons with sharp corners, they would certainly change the feel of the image. </p><div></div>

<p>night time photography does not require fast lens nor does it require high ISO. If you don't understand this much then you still need to study photography. It would be helpful if you would give more info in what exactly you are trying to accomplish when you say night time photography.</p>

<p>I used to own fast lenses, but discovered that I was not using them much for the greatly reduced depth of field that I found to be their long suit. Over the last generation or two of sensors the ability to use very high ISO and get good quality has greatly reduced the need for a fast lens to deal with low light situations. Except for long telephoto lenses, I no longer see any real advantage to a fast lens for my own work. I'm sure some others will see things differently. I think high ISO does much more for low light work than a fast lens does. I can gain more than just a stop or two by using ISO 1600 or 3200 than a single stop by using a faster lens.</p>

I like the 85 1.8 because it's bright to see through, fast aperture and light weight. I've been using mine since it came out

on AF about 1990.