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

Reply
 
Thread Tools Search this Thread
Old May 11, 2004, 12:32 AM   #1
Junior Member
 
Join Date: Apr 2004
Posts: 25
Default

I'be been reading up on all the forum threads about back-focus on the Nikon D70 and got the impression that it is a common problem amongst the various markets.

Is back-focus really a design/production deficiency or merely something played up by forum posters who designed many ad hoc tests for the camera?

From a technical perspective - is it possible for an entry-level dSLR to have autofocus accuracy measured in one or two inches?? And, on wide aperture of the kit lens, how deep is the typicalDepth of Focus??

Assuming that accuracy canbeto the nearest inch but DOF is more than(say) 5 inches, it would be pretty difficult for someone to conclude a camera has back-focus.




















Buckrogers is offline   Reply With Quote
Sponsored Links
Old May 11, 2004, 1:08 AM   #2
Senior Member
 
Join Date: Jun 2003
Posts: 172
Default

I had/have no problem at all with back-focussing. This question would probably do better in the Nikon DSLR section of this forum. There is a thread there going into some detail the supposed problems with D70s..

As one salesman said to me.. it only takes 5 or 10 loud D70 owners with a problemto overwhelm the rest that are having no problems..
PlatinumWeaver is offline   Reply With Quote
Old May 11, 2004, 3:20 AM   #3
Junior Member
 
Join Date: Apr 2004
Posts: 25
Default

Yes, I have read the threads in the Nikon SLR forum but I had wanted to get some views from other Camera users who would give impartial opinions. I'm not asking about whether the D70 does or does not have the BF problem - merely whether, from a technical/optical point of view, it would be possible for a perfectly OK camera to be diagnosed as problematic.




Buckrogers is offline   Reply With Quote
Old May 11, 2004, 3:36 AM   #4
Senior Member
 
Onyx's Avatar
 
Join Date: Jan 2004
Posts: 402
Default

It's entirely possible that the focusing accuracy out of factory is within "acceptable" limits but when tested more precisely (ala shooting wall charts on 45 degree angles, etc) and to which you rightly suggest measurements made could be more precise than should be applicable,the focus manifests itself as having slight errors - which for a consumer who just spent a load of hard earned money on the product, may be an unacceptable margin of error. Hence the many posts by a select few exaggerating thenature of the problem.

I know of someone with BF "problem" with Canon L glass, so it's not entirely limited to 'consumer grade' lenses either.

Ken Rockwell's D70 review (http://www.kenrockwell.com/nikon/d70.htm) sheds some light into this matter - (Ken retains copyright for the quoted passage below, I did not seek his permission to reproduce it but I hope doing so does not inflict harm upon his intellectual property rights and is considered acceptable use)


[align=left]There is a teeny problem in two of the four D70s I've used. The focus calibration was off by about a tenth of a millimeter (that's why I say teeny). Nikon of course will adjust this under warranty if it's a problem. With the f/3.5 and slower lenses people usually use it's not much of a problem, and at regular shooting apertures of f/8 or so its completely invisible. On the other hand, if you have fast lenses that alone cost more than the complete D70 kit and you shoot them wide open your focus may be a little off at shooting apertures of f/2.8 and faster with some of the samples I tried. Shooting my $1,700 28mm f/1.4 lens wide open at f/1.4 was useless on two cameras, but of course OK at normal apertures. Again just something to watch for on the final images shot at large apertures; you won't see this through the finder. If you do see it it's simply the image being focused on something just a little behind where it should have, which is usually invisible if you have enough depth of field, and of course Nikon will stand behind it if it really is a problem. The sample I tried on 05 May 2004 was perfect with the 85mm f/1.4 AF lens wide open.[/align]

[align=left][/align]
Onyx is offline   Reply With Quote
Old May 11, 2004, 4:07 AM   #5
Junior Member
 
Join Date: Apr 2004
Posts: 25
Default

Onyx, thks for that link. Now I feel much comfortable about buying the D70 unless I can think of some other excuses to keep the cash in the wallet!
Buckrogers is offline   Reply With Quote
Old May 11, 2004, 1:25 PM   #6
Member
 
tksuther's Avatar
 
Join Date: Apr 2003
Posts: 45
Default

Buckrogers wrote:
Quote:
I'be been reading up on all the forum threads about back-focus on the Nikon D70 and got the impression that it is a common problem amongst the various markets.

Is back-focus really a design/production deficiency or merely something played up by forum posters who designed many ad hoc tests for the camera?

From a technical perspective - is it possible for an entry-level dSLR to have autofocus accuracy measured in one or two inches?? And, on wide aperture of the kit lens, how deep is the typicalDepth of Focus??

Assuming that accuracy canbeto the nearest inch but DOF is more than (say) 5 inches, it would be pretty difficult for someone to conclude a camera has back-focus.
Quote:
For what it's worth..................my D70 had this problem - also washed-out colors in outdoor shots. I returned it for a replacement. The replacement works perfect - must have been a calibration problem.


















tksuther is offline   Reply With Quote
Old May 12, 2004, 1:40 AM   #7
Senior Member
 
Join Date: Jun 2003
Posts: 172
Default

I dont think i've got any problems with washed out colours.

http://www.platinumweaver.net/images/autumn.jpg
PlatinumWeaver is offline   Reply With Quote
Old May 12, 2004, 8:13 AM   #8
Member
 
tksuther's Avatar
 
Join Date: Apr 2003
Posts: 45
Default

PlatinumWeaver wrote:
Quote:
I dont think i've got any problems with washed out colours.

http://www.platinumweaver.net/images/autumn.jpg
Nope - looks good to me. What are your settings here - Normal? Vivid? Saturation? Just curious.
tksuther is offline   Reply With Quote
Old May 12, 2004, 9:09 AM   #9
Senior Member
 
Onyx's Avatar
 
Join Date: Jan 2004
Posts: 402
Default

Very nice pic PW.

I like the rest of your site too (bottom coloured undies indeed...)
Edit: darn censor, abbreviated "assorted".
Onyx is offline   Reply With Quote
Old May 13, 2004, 3:47 AM   #10
Senior Member
 
Join Date: Jun 2003
Posts: 172
Default

tksuther wrote:
Quote:
PlatinumWeaver wrote:
Quote:
I dont think i've got any problems with washed out colours.

http://www.platinumweaver.net/images/autumn.jpg
Nope - looks good to me. What are your settings here - Normal? Vivid? Saturation? Just curious.

Sadly, I think that was a shot taken in full-auto mode, 1/100, f4.5, 55mm, spot metering..

Shot in raw and then changed the white balance from whatever it was preset on to 'daylight - sunny' if I recall correctly.

Onyx wrote:
Quote:

Very nice pic PW.

I like the rest of your site too (bottom coloured undies indeed...)
Edit: darn censor, abbreviated "assorted".
I have no idea what you're refering to, and that worries me heaps! :-)

Thanks for the positive comments, it was just a result of having 5 minutes or so to test out my new tripod, camera, filter.. and so on..
PlatinumWeaver 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 11:49 AM.