Photoclubalpha

Yesterday night one of my friend was at home, and he bring with him the D300s + 18-200VR.

So I was showing him the difference in full frame at 200mm compare to a APS view.

But ... my very weird surprise was that from the same place, with only changing the camera : A900 + 200mm HS 2.8 at F2.8 and the D300s + 18-200VR at F5.6 at 200mm found that the angle of view was almost identical ... Even on the picture taken ...

So, my question ... is it possible that the Nikon 18-200mm is in fact mostly a 135mm at the end of the zoom ??? I don't know if other people can have the same setup in there hand to to the test. Or ... what I think it probably not possible the 200mm of Minolta is in face longer ...

Unfortunately I don't have the picture in my hand of the D300s, but probably I can ask my friend if they are still in his camera.

Regards,

Frank

That seems most odd Frank, the 18-200 should be roughly 36-300 on APS-C format, I could easily believe the lens might not 'be' 300 at full zoom, it might be a little short of that maybe but the angle of view should be much smaller than a 200mm prime on FF, it all sounds really strange. Unless Nikon are doing something unusual like giving the lens specs in APS-C conversion figures and not as FF figures or something, like the lens is actually not an 18-200 (36-300) equivalent but something weird like a 12-135...and I don't think that's likely either...hmmm
Greg
ps. I wonder if there is a WA filter for that lens? (long shot)

InTheSky wrote:So, my question ... is it possible that the Nikon 18-200mm is in fact mostly a 135mm at the end of the zoom ??? I don't know if other people can have the same setup in there hand to to the test. Or ... what I think it probably not possible the 200mm of Minolta is in face longer ...

Someone else will probably reply with a better explanation, but I have read several times that many internal focus zooms are only their marked focal length at infinity. I assume you were not shooting at infinity. The first time I recall reading about this was in PopPhoto in about 1996. They said that the second version of the Tamron 28-200mm that had internal focus seemed to only be about 135mm at short distances.

I was focusing at about 20 feet (my coucou wooden clock). So, yes I was as we can consider close distance for a 200mm, but I think a normal distance for taking bird or some small animal.

Very interesting information you have provided to me there, this is new for me.

This means that this is an another difference between a zoom and fix lens.

I will try to do a test with my Beercan today a 200mm vs the 200mm HS ... to see if Minolta was lying on the focal in the past hi hi.

Regards,

Frank

InTheSky wrote:I will try to do a test with my Beercan today a 200mm vs the 200mm HS ... to see if Minolta was lying on the focal in the past hi hi.

Yes, let us know what you find out. The beercan does not have internal focus.

I think that and the newest Nikkor 70-200 VRII is shorter than 200mm at the long end.

Here is the old 70-200 @ 200mm and 2m distance:


And the new VR II:



More here: http://www.bythom.com/nikkor-70-200-VR-II-lens.htm

That sounds a reasonable explanation Henry, lens design sometimes is a funny busyness, I remember once trying out a new Sigma zoom (MD mount) for the weekend, it was nice and compact for a good general purpose zoom (I forget the actual figures), but it had one serious flaw (in my eyes anyway), it's focus would vary with the zoom and therefore useless for my purposes, I had the habit of zooming in, focus, zoom back out, compose, and take the shot. With that particular Sigma zoom you only had to change the zoom a little bit and you had too re-focus again, very difficult for me too bother with. (I bit the bullet and ordered the Minolta MD70-210 f4, at a price you would pay for a decent second hand car at the time).
Greg

Unfortunately I didn't found time to do testing this weekend (new dad job ).

Those new lenses like the Nikon are kind of the best zoom ever made for the detail at long end 200mm on a full frame camera. But ... If in fact the lens test done by many web site are on a sheet of paper with plenty of small line to determine this level of detail, by the distance they are from the subject in fact they are testing a lens a 135mm ... compare with older design at 200mm ... That bring me to the conclusion that they should build a king of big wall reproduction of the same resolution chart and shot it from at least 30m

This is interesting information even for the Dpreview testing system ... that behind this Technical expert image ... they should be pay a very big attention to this for they detail testing, chromatic aberration and a last one important : Anti-Vibration...

There is a difference between compensation for Anti-vibration for a subject that in fact should be far from the camera (1.5x)...

Probably I'm pushing too far my observation (in fact ... it is worst in the word of electronic for specification and real world)

Regards,

Frank

Everything you say has been covered in my British Journal test of the Nikon lens. The change in internal focus zoom behaviour with the new lens keeps the image angle constant as you focus, during video shooting. It is very precise. A 'normal' lens has a very different effect, but the new Nikkor works brilliantly for video.

Re large test chart - that is why I stopped doing chart tests maybe 20 years ago. 27X the focal length was the requirement with my charts. It was nonsense. So I stopped producing nonsense, took pictures and learned how to 'read' lenses from the way they imaged a wide range of subjects at all distances.

David

Thanks for the information David.

My reaction was more because I love too much portrait at 200mm. And I was surprise that with this kind of zoom lens you will never be able to have this effect. (but 135mm is good too for portrait ).

Regards,

Frank

David Kilpatrick wrote:Everything you say has been covered in my British Journal test of the Nikon lens. The change in internal focus zoom behaviour with the new lens keeps the image angle constant as you focus, during video shooting. It is very precise. A 'normal' lens has a very different effect, but the new Nikkor works brilliantly for video.

More of that claim that adding video to DSLRs does not change still shooting. Right!

Walt

It also works for fashion shoots, tracking and AF-continuous following stills of sports, models etc. As the subject approaches with the old Nikkor, the effect of closer focusing is (as with conventional lenses) to narrow the angle of view. With the new design, the background does not change scale. If you have a building framed precisely when focused on the building, then a model enters the shot ten feet from the camera, the building stays exactly to the original scale even when the focus shifts to the model.

This is how the best TV camera zooms are made, as it avoids strange effects with the background 'zooming' when focus is shifted between two points (say two faces). But it can also work really well in sports, fashion and other types of photography where tracking a moving subject coming towards the camera is common.

With a lens which does not 'change focal length' (as people see it) focusing closer changes the angle of view. Nikon instead opt for a stable angle of view.

It is not worse, in many situations it's better. A spin-off of this design is greatly improved flatness of field at close distances, making the entire field of a full frame shot sharp instead of falling off badly to the corners at wider apertures. Bokeh is improved for the same reason (flatter field).

David