Lens design for digital camera

[Abitconfused]

I believe I read somewhere that lenses made for digital cameras need direct light more perpendicularly to the sensor because the photosites are in little "wells" whereas the surface of film is more forgiving. Is this true?

[Shadowman]

I've never seen the sunny 16 rule adjusted for digital cameras, well the ISO portion for digital might be more refined. I would think lens design (film or digital) would have more bearing on quality than specific type.

[dem]

I do not think it is true. For starters, at a given aperture, focal length and focus distance, it is impossible to control the angle at which the light hits the sensor. That is by the lens design.

There is more than one ray of light from the subject that is responsible for making an image - all rays of light passing through the front element get refracted and hit the same pixel at various angles. The shorter the focal length, the wider this "family of angles". The further away from the centre of the image, the less perpendicular to the sensor this "family of angles" is. It is indeed a problem for digital sensors, as photosites are more sensitive to the rays falling perpendicular. This is known as "pixel vignetting" and is reduced by adding microlenses to each photosite of the sensor, i. e. by the sensor design, not the lens design.

[xpatUSA]

As I understand it, a lens can be made that effectively has parallel rays normal to the sensor surface. the property being "telecentricity" which I find . . a bit confusing.

https://en.wikipedia.org/wiki/Telecentric_lens

enjoy!!

[chauncey]

I don't have a clue, but it would be interesting to see two shots, one film and one digital,
shot using the same lens.

[tclune]

Wikipedia's article on the history of lens design indicates that the main change has been that lenses are now sometimes designed with an eye to post-processing. So, for example, the lens design compromises tend to accentuate lateral chromatic distortion because it is so easily fixed in post. That more or less accords with my experience. FWIW

[Manfred M]

There is absolutely a difference, and yes the use of a digital sensor does impact lens design.

Film is quite thin when compared to the sensor stack, which in addition to the sensor, it will have other optical elements sitting in front of it. Relative to a piece of film this stack is quite thick, and so does need to be taken into account when the lens is being designed. I have read somewhere that Leica uses the thinnest stack and the mFT cameras (Olympus and Panasonic) the thickest.


https://wordpress.lensrentals.com/bl...dapted-lenses/

So yes, lenses are now being designed for use with digital camera and your old legacy lenses will probably not work as well.

[Dave Humphries]

~ for example, the lens design compromises tend to accentuate lateral chromatic distortion because it is so easily fixed in post. That more or less accords with my experience. FWIW

I believe that is the case with 4/3 and m4/3 lenses on mirrorless bodies.

Likely also applies to vignetting (also readily fixed in 'post' or jpg creation at time of capture - if the lens is in the camera's 'database'), whatever the cause; lens or pixel based.

[Black Pearl]

You read correctly Ed, probably an Olympus article or a similar one on a clean-sheet designed digital system like M4/3:

“ZUIKO DIGITAL” lenses are designed exclusively for digital SLR cameras, allowing all necessary light to hit the image sensor at a perpendicular angle.

http://www.olympus-esystem.com/dea/t...-position.html

I have read several other articles along the same lines in the past but can't put my finger to them so it definitely is a thing and is possible.

[NorthernFocus]

...So yes, lenses are now being designed for use with digital camera and your old legacy lenses will probably not work as well.

Thus giving a different meaning to the often heard "they don't make them like they used to".

[marlunn]

and yet many enthuse over using old film era lenses on dslrs and glory in the 'quality' of the image they get with the old lens compared to the 'modern' version

[Manfred M]

and yet many enthuse over using old film era lenses on dslrs and glory in the 'quality' of the image they get with the old lens compared to the 'modern' version

Another example of how facts never seem to influence how people judge things...

I personally find that modern "pro" lenses definitely outperform many legacy lenses. New modern lens coatings, high index of refraction glass and aspherical lens elements were rarely used in a all but the most expensive legacy glass, yet somehow people seem to discount how these relatively recent (last 10-15 years) improvements have improved modern optics.

In my experience, modern lenses can be optically superb, but the mechanical components of the legacy lenses definitely outshine what we see on many modern lenses.

[NorthernFocus]

Another example of how facts never seem to influence how people judge things....

That's one of my favorite expressions. "Once someone's mind is made up whatever you do don't confuse them with facts."

I just shake my head when I read lens reviews by well respected(i.e.popular) photography personalities who make comments about one lens FEELS better built than another.

[loosecanon]

When introduced the 4/3rds system touted the advantage of the closer to parallel light rays, with the lens distance to the smaller sensor. Then mirrorless came in, lens flange to sensor distance shortened, and somehow this doesn't matter. In practice micro lenses on the sensor have resolved much of the problem. However the location of the lens exit pupil does effect the sensitivity of focus points - many of Canon's older lenses cannot use all the focus points for this reason.

[miatab]

"and yet many enthuse over using old film era lenses on dslrs and glory in the 'quality' of the image they get with the old lens compared to the 'modern' version." All in the eye of the beholder, eye believe.

[Tronhard]

OK I admit I have not read every post in this series, and probably I should, but logic tells me that since the days of film photography considerable improvements have been made in the technologies to design and produce quality lenses. I would HOPE that a newer lens is more likely to be a better performer than an older equivalent version of the same thing. I would also note that modern lenses are generally packed with things like image stabilization, autofocus and electronic communications that their analogue antecedents did not have to deal with.

"and yet many enthuse over using old film era lenses on dslrs and glory in the 'quality' of the image they get with the old lens compared to the 'modern' version." All in the eye of the beholder, eye believe.

[John 2]

OK I admit I have not read every post in this series, and probably I should, but logic tells me that since the days of film photography considerable improvements have been made in the technologies to design and produce quality lenses. I would HOPE that a newer lens is more likely to be a better performer than an older equivalent version of the same thing. I would also note that modern lenses are generally packed with things like image stabilization, autofocus and electronic communications that their analogue antecedents did not have to deal with.

I haven't read all of the above either but a fair bit. I must admit that when Fuji started to make it's X series lenses available to high acclaim, I couldn't understand why anyone would want to give up the benefits of auto focus etc. just to fit and use a legacy lens for the sake of it. There is maybe, an argument that it is an inexpensive way of increasing the range of focal lengths available - perhaps for the time being but that's a long way from claiming any optical benefit. However, I think that it might just be a fairly normal part of the human condition. Photographic lenses are not the only area to cause this sort of behaviour. Any body still using vinyl rather than Cd's and comparing re-issues of the same track on both? Sinatra's "Songs for Swinging Lovers" was much better as an LP than it's CD re issue (- and that could keep us going for a fair bit as well)

[Manfred M]

Any body still using vinyl rather than Cd's and comparing re-issues of the same track on both? Sinatra's "Songs for Swinging Lovers" was much better as an LP than it's CD re issue (- and that could keep us going for a fair bit as well)

What's a CD? Aren't those the strange little disks that were replaced by mp3s over 20 years ago?

[John 2]

I think there was an attempt but you know, anything that doesn't go round and round, can't produce good quality sound.

[Black Pearl]

I play more vinyl than I do CD's - in fact I can't recall the last time I even put a disc into my CD player as I ripped them all to FLAC's for streaming. Now thats not because I think they sound better (different yes) its just that I rather like the experience of spinning an LP.

As to old lenses then I have yet to find one that doesn't have a technically better quality newer version - however - some of the older lenses have a 'look' or a particular characteristic that many people find appealing. I rather like the hexagonal OOF highlights from my Pentax-F 50mm f1.7 which is something you tend not to get today with modern rounded apertures. I'm not saying its better, but it does give me a creative tool to use.