Manual lenses sharper on D90 than AF?

<p>I have never really paid attention to using manual lenses on my digital SLRs. I recently began experimenting shooting my AF lenses in manual focus on my D90 and the shots that I take are all sharper in manual focus vs auto. Is this just me using the autofocus incorrectly or is this pretty much the norm? If this is normal, I can't believe I have not looked into manual focus lenses more as focusing in manual is really easy with the 'dot' confirmation. My eye sight is not the best thru the viewfinder so I always dismissed the idea of manual focus. I know the D90 does not meter, but with digital I can guess and snap the picture and correct exposure if need be after seeing the shot.</p>

<p>If manual focus lenses generally are this sharp, can anyone recommend some longer telephoto manual lenses (under $500 or so) for me to play with? Does anyone have experience with the manual 105mm 2.8 micro as that now sounds pretty interesting as well?</p>

<p>I'm not sure I would say that manual focusing is always more accurate than AF, but I've had very good luck using manual focus lenses on my F100. The dot confirmation works well. That said, I'm probably paying closer attention to focus while manually focusing, hence the perception that it works better than AF.</p>

<p>The manual ones I've found very sharp are the AI 80-200 fixed f4.5, 28/2.8, most any older non AF 50mm, favorite 105/2.5 PC coated version. <br>

The only prime I have that is not noticeably sharper than any of the AF zooms is the latest 35/1.8G DX AFS. </p>

<p>I must be missing something here: if your AF lenses are sharper manually focused than using the AF, then you need to have the camera checked out - or check for yourself whether it is front- or backfocusing.<br>

I find it virtually impossible to manual focus with the focusing screen on my D200/D300 - image appears sharp in the viewfinder but will be slightly OOF on the sensor. Relying on the focus confirmation dot improves things considerably, but is no way to shoot anything that moves. <br>

Since the dot information comes from the same AF module that is used when you auto-focus your AF lenses, I don't understand how there can be a difference in sharpness between AF and manual focus of AF-lens using the dot confirmation - unless communication between camera and lens isn't accurate in AF mode.<br>

I don't understand how from your experience of manual focusing AF lenses you arrive at the idea that manual focus lenses are sharper - some might and some may not. For example, my 30-year old 20/4 AI lens is sharper than the 20/2.8 AF at apertures larger than 5.6 whereas the 50/1.8 AF beats my 50/1.8 AI-S at anything below 5.6.</p>

<p>Autofocus is a misnomer. The more you use your equipment, the more proficient you will become. This goes for focus, auto or manual. It might be interesting to know which lenses you are using and how you are using them. There are factors which have a bearing.<br>

I have a 105 micro 2.8. While it is an excellent micro lens, it just isn't very sharp for landscapes. Zooms are notoriously inconsistent. They have sweet and sour spots.</p>

<p>With my D80, the dot confirmation comes on for a large range of focus and therefore is very imprecise. Focus on something with your D90 and move the focus in and out to see if it is like this. </p>

<p>You might find a used 300mm slower tele at that price. Nikkors should be pretty good. I use a 300 4.5 edif which I like for landscapes but not for close-ups.</p>

<p>Rather than lenses which are incapable of focusing automatically, a lens which does not zoom (prime) is frequently somewhat sharper. Some of these cheap, used primes also are not able to focus automatically.</p>

<p>On my D300, on some of the AF-C settings, the suutter can be released before auto focus has completed. Maybe that is the same on the D90.</p>