3 Questions about digital nikons
1) do lenses lose any image quality because of the magnification factor on non-full frame sensor cameras?
2) does Ai conversion cause the value of old lenses to drop?
3) if my old lens has some small specs of dust that dont appear on film, will the dust particles be more likely to appear on digital?
#1. "RE: 3 Questions about digital nikons" | In response to Reply # 0JonK Nikonian since 03rd Jul 2004Sat 11-May-13 12:05 AM
1) No. Image quality is better because only the center portion of the lens is being used, and lens performance is best in the center.
2) No, it raises the value — the lens is more useful on modern cameras.
3) Dust inside a lens is not normally visible on an image, film or digital. If you have something inside a lens large enough to show up on film, it will show up on digital.
A New York City Nikonian and Team Member
Please visit my website and critique the images!
#3. "RE: 3 Questions about digital nikons" | In response to Reply # 1Sat 11-May-13 01:38 AM
I was just reading a review of an old 20mm lens on the ken rockwell site and he stated
"...If shot on DX, which is silly, you see more distortion because you're only using the center of the image, where distortion is strongest, but much easier to correct. "
He is claiming that the center of the lens is more distorted?? he also claims shooting this on DX is silly for some reason..
#4. "RE: 3 Questions about digital nikons" | In response to Reply # 3RABaker Registered since 30th Sep 2003Sat 11-May-13 02:56 AM
If you read enough on Ken Rockwell's site you will come across a few references he makes himself to his deliberately "provocative" statements - made specifically to stir up controversy and stimulate comment (and, not incidentally, to bring more visits to his site by folks wanting to see if he really said what others are quoting -- advertising is sold based on the number of visits to a site). Although there are many who do not consider Ken Rockwell worth reading (and I am one), I know enough about him to know that he is aware that lens distortion in virtually all lenses is greatest near the edges, not the center. So it is pretty obvious that this particular statement was made deliberately in the hope of generating discussion (and more site "hits").
By the way, I found Ken Rockwell's site many years ago and read a lot of it. Then I happened to read a comment left by an individual about a lens review that Ken had posted. The comment was questioning Ken on some specific factual errors (rather glaring errors) in what Ken wrote in his physical description of the lens. In response, Ken admitted that he had never actually had or used the lens and wrote his review based on advertising copy and other reviews he had found online. I stopped reading his stuff after that.
When asked about K. R. I always suggest that anything he says should be taken with a large grain of salt, and when he says something that goes against all previous testing and facts it needs to be recognized for what it is - a deliberate attempt to stir things up and to bring more traffic to his site.
#8. "RE: 3 Questions about digital nikons" | In response to Reply # 3ericbowles Nikonian since 25th Nov 2005Tue 14-May-13 08:59 AM
Normally using a full frame lens on a DX camera means you are cropping the outer part of the image - the place where the most distortion occurs. There are some types of distortion that show up in the center of the frame - or at least around the center. Since the DX crop is rendered larger for the same size print, I guess you could argue that visible distortion or lens issues are magnified on DX. But in my mind, that is a bit of a stretch.
Probably a bigger issue with an older wide lens like the 20mm is that new designs generally have provided a lot of improvement. Wide lenses tend to have a good bit of distortion, and newer designs have gone a long way to eliminate or reduce those problems. Wide lenses are also subject to flare and other problems. The coatings on newer lenses provide a lot of improvement to older lenses in difficult shooting conditions. And almost all new lenses are better optically than older lenses.
Here's a good article from Thom Hogan on lens kits. It contains some of the older lenses, as well as links ot other reviews. Thom tends to have a pretty good perspective.
And Here's a link to lens reviews by Bjorn Rorslett. He's also a pretty good point of reference. You'll note that he provides feedback on some lenses for multiple cameras - and the performance can vary.
Nikonians membership — my most important photographic investment, after the camera
#9. "RE: 3 Questions about digital nikons" | In response to Reply # 3nrothschild Registered since 25th Jul 2004Tue 14-May-13 11:50 AM
>> he also claims shooting this on DX is silly for some reason..
As best I understand his logic, his reasoning is as follows:
1. A 20mm FX lens (and all other very wide FX lenses) is generally an expensive lens. Even the old Ai/Ai-S models sell for good money.
2. If you shoot FX you have to pay the freight in order to get something approaching an ultra-wide field of view, and that is what the 20mm FX lenses are all about.
3. On DX, that is only a 30mm FX equivalent FOV, which is not exactly "ultra-wide".
4. 20mm class DX lenses are cheap, relatively speaking, with lots of choices in all the 16-17-18 to something zooms.
From that perspective, it might not make sense to buy an FX 20mm lens specifically to shoot DX in order to get the resulting FOV. But I own a 20mm f/2.8 Ai and never thought it was "silly" to shoot it on DX. It takes great images. But if my objective is to get as wide as possible for a certain expenditure, it *might* not have been the best choice.
That decision depends on the feature set and what you think of the various DX lenses, each taken individually. There are no DX primes in that range, for example. And few offerings at f/2.8, and they are quite expensive, and zooms (could be good or bad depending on your thinking).
As mentioned previously you should take anything he says with a pile of salt, not just two grains .
my Nikonians gallery.
#5. "RE: 3 Questions about digital nikons" | In response to Reply # 0
To provide another response to your original questions:
"1) do lenses lose any image quality because of the magnification factor on non-full frame sensor cameras?"
No - not just because of the size of the sensor (which is what causes the so-called "magnification factor" or "crop factor"). However, the same lens may provide a better quality image on an FX sensor than a DX sensor simply because of the specific sensor used in each camera and based on how something as nebulous as "image quality" is determined. Most FX sensors have better dynamic range and better noise performance than most DX sensors, so that alone could make an image "better quality" if these happen to be critical factors for a particular image. But if an image is captured under conditions where these particular FX sensor advantages will have little or no effect, then there will likely be very little difference (if any) in overall image quality.
"2) does Ai conversion cause the value of old lenses to drop?"
In general, no. This would occur only if the lens happens to be in high demand by collectors. If it is, then any change from its original form will decrease its collectable value. For lenses that are not considered "collector's items" the AI conversion may well help its resale value a bit.
"3) if my old lens has some small specs of dust that dont appear on film, will the dust particles be more likely to appear on digital?"
No. It takes a LOT of dust, or some very large particles, to have a visible impact on an image (with film or a digital sensor). With lots of dust there may be an overall image quality degradation along with a loss of contrast. But a few dust specs in a lens, especially if toward the front of the lens, will have no visible impact on images. Dust on or near the rear element of the lens can have more effect on images, but even there it takes quite a lot of dust to have a visible impact.
#7. "RE: 3 Questions about digital nikons" | In response to Reply # 0
An interesting article about lens dust:
An interesting article about lens scratches:
Seattle, WA, USA
D700, D200, D70S, 24-70mm f/2.8, VR 70-200mm f/2.8 II,
50mm f/1.4 D, 70-300mm f/4.5-5.6 VR, 18-70mm f/3.5-4.5 DX
#10. "RE: 3 Questions about digital nikons" | In response to Reply # 7Enthus_Photo Registered since 15th May 2012Sun 16-Jun-13 11:47 PM
>An interesting article about lens dust:
>An interesting article about lens scratches:
>Seattle, WA, USA
>D700, D200, D70S, 24-70mm f/2.8, VR 70-200mm f/2.8 II,
>50mm f/1.4 D, 70-300mm f/4.5-5.6 VR, 18-70mm f/3.5-4.5 DX
Roger is pretty awesome...
- - - - - - - - - - - - - - - - - - - - - - - - - - -
Visit my blog: enthusiastphotographer.com