Go Back   Steve's Digicams Forums > Digital SLR and Interchangeable Lens Cameras > Nikon dSLR

Reply
 
Thread Tools Search this Thread
Old Nov 19, 2002, 7:22 PM   #1
Junior Member
 
Join Date: Oct 2002
Posts: 2
Default D100 and wide angle

I presently use an F3 with a 28-80 zoom. I need that 28mm when taking race car pix in the pits, it allows me to get very close to the cars and snap a quick photo-oftentimes thats all there is time for. If you go to a 35mm lens you have to back away from the cars just far enough that people will walk in front of you and block your shots. The 28mm gets you close enough so that this is not a problem...plus... at 28 to 30 mm there is no noticable distoration in the image, if you reduce to , say, 24mm, you will start to get some distortion or "fish-eye" in your image.
Now for my dilema. I really, really want a D100. By using the 1.5 conversion factor I find that the 17-35, or 18-35 zoom lens will get me back to that 28mm that I need. My big question, and the factor that will determine weather I buy a D100 or not, Will the 17 or 18 mm setting with the D100 give you that "fish-eye" distortion or will it give the same image as the 28mm lens does on a 35mm film camera?
jimxty is offline   Reply With Quote
Sponsored Links
Old Nov 23, 2002, 2:10 PM   #2
Moderator
 
Join Date: Jun 2002
Posts: 157
Default Cropping factor

The D1/D100 series cameras, like most other DSLRs, have a smaller imager than film. Thus, the light from the lens's exit pupil falls partially outside the imager's perimeter. This means that the imager only records part of the image circle projected by the lens. In the case of the D-series bodies, the CCD captures 2/3 of the image circle and therefore crops the rest.

What does all of this mean when applied to your question?

The optics remain the same. The character of the focal length of a specific lens remains the same, but you are only using the central 2/3 of the image. The 17-35 renders less-distorted images than the 18-35, and lines are nearly straight -- however, you still have to keep the image plane parallel to your subject to maintain spatial relationships, and as the outer areas of the subject as rendered to the edges of the frame are very likely to be at significantly different angles to the imager than the central frame, lines will tend to diverge at the outsides of the frame more as you go to wider angles of view.

Bottom line? Even though the 17-35 is significantly better than the 18-35 with regards to distortion and other criteria, you still have the issues with ultra-wide angle when approaching the wider end of the lens. Keep them in mind when framing the shot.
RonReznick is offline   Reply With Quote
Old Dec 1, 2002, 6:55 AM   #3
Member
 
Join Date: Jun 2002
Posts: 35
Default Re: D100 and wide angle

Quote:
Originally Posted by jimxty
My big question, and the factor that will determine weather I buy a D100 or not, Will the 17 or 18 mm setting with the D100 give you that "fish-eye" distortion
Yes, lens optics don't change.
scorpio_fish is offline   Reply With Quote
Old Dec 1, 2002, 12:52 PM   #4
Moderator
 
Join Date: Jun 2002
Posts: 157
Default

No, you don't get fisheye distortion. Lines remain pretty straight on the 17-35 AFS, but at the wide end there is a very slight bowing near the edges of the frame. There is also the issue with keeping the imaging plane of the camera parallel to the subject lines to avoid convergence -- just as there is on any wide angle. This has nothing at all to do with the D100 -- actually, with the 1.5x field of view crop you are working with the center 2/3 of the lens's image circle and are getting the best out of the lens's optics. It has to do with the character of wide angle lenses in general and the 17mm focal length in particular.
RonReznick is offline   Reply With Quote
Old Dec 7, 2002, 8:52 AM   #5
Member
 
Join Date: Jun 2002
Posts: 35
Default

Ron, I don't disagree with anything you've said. What I think Jimxty is talking about is perspective. I'm not sure how to desribe it, but I can describe an example.

Take a head and shoulders shot of someone holding a pair of binoculars to their eyes with say a 20mm lens (up close and personal).

Take the same shot with a longer lens, say 105mm, from a distance that gives the same frame. The size relationship between objects at different distances (front of binoculars vs. head) are quite different.

I think that this is what Jimxty was describing and of course, this doesn't change for D100 vs. full frame film. Not that the lens itself creates barrel distortion at a wide setting.
scorpio_fish is offline   Reply With Quote
Old Dec 9, 2002, 7:13 PM   #6
Junior Member
 
Join Date: Oct 2002
Posts: 2
Default

Thank you both for your replys. I finally got a chance to look through the viewfinder of a D100 and its film counterpart with the 17mm lens mounted. You can readly tell the differance-on the D100 the field narrows, and the distance from the subject seems a little further away IOW you really do see the 1.5 factor with the D100. The 17mm lens seems to essentaly turn into a 26.5 (28)mm lens. I also found the 17mm lens to be very clear and distoration free, espically when mounted on the digital body-I wonder how the 18mm lens compares?
At any rate my look through the viewfinder has convinced me to become a D100 owner-now I am waiting for a price reduction perhaps after Christmas.
jimxty is offline   Reply With Quote
Old Jan 1, 2003, 12:44 AM   #7
Administrator
 
steve's Avatar
 
Join Date: Jun 2002
Posts: 2,535
Default

New Nikkor 12-24mm DX lens is coming soon:

http://www.steves-digicams.com/digin...html#nikkor_dx

-Steve
steve is offline   Reply With Quote
 
Reply


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off



All times are GMT -5. The time now is 4:52 AM.