BIG MEGAPIXELS small lenses?

[CanikonLover]

Hello Ladys and Gents,

first of all that's going to be a no whining thread. It's more of a question for which I got no answer. Maybe some of you got one or can tell me how to test it DIY. I'm doing apprenticeship for photography so I'm partly working in a firm for industrial photography and partly at school. There is one professor he is sort of a photo scientist and he claims all Canon Nikon and whatever lenses (within the 36x24sensor range) not be sharp enough or physically not able to reveal higher megapixel images. The lenses would reach a high level of resolution but could not handle those high megapixels. And again I'm not saying thats my opinion. I just started to think about what lenses to buy for my future job and if you are a student like me you don't have that much money to spend on wrong gear. So you think twice about what to buy. That is why I was wondering about will future lenses fit better to high megapixels...or is it the other way round that the lenses are able to deliver even better images than the megapixels we even have right now?

I heard about testing lenses with lines on a white surface. The moment where the lense cannot divide those linse because it simply cannot deliver and merges them to one fat line...

Sorry in advance my english is pretty ok i guess but it's hard sometimes for foreigners to speak in an appropriate vocabulary. I try my best.

Regards

 

[SwissBear]

Zeiss will release some lenses that are supposed to deliver enough resolution:
http://blogs.zeiss.com/photo/en/?p=2860#more-2860

 

[Ryan708]

I praise your ability to speak english at all, it is my only language and I have enough trouble with it! :-/

Ok, about your question: This is a grey area. Lenses produce an analog image, and sensors are digital.
A 10 MP sensor has about 10 million possible points of data (ignore the RGB filter subject). Even a soft lens has a near infinate number of data points, being an analog device.

So, with any lens worth its lens-cap, will resolve more detail with more megapixels, but eventually the results are not noticable

However, the sharper a lens is, the more precise the detail hitting the sensor will be, giving each pixel it's own data, and therefore makeing a crisper image, even if the MP are the same.

Canon has some of the sharpest lenses out there, and I have gotten to use one of them quite a bit, the EF 70-200 F/2.8 IS II

On an 8 MP 30d this lens will outresolve My tamron 70-300 (at the same 200 MM setting)by a tad on my 18 MP 60d
So essentially my tamron is sending "blur" to 10 of my 18 megapixels. BUT If the tamron is put on the 30d, (8 MP) the results are a fair amount worse than on the 18 MP.

conclusion: Better glass helps more than more megapixels, But BOTH do help.

 

[CanikonLover]

Ah ok great. That is what i thought. My boss told me some lenses might not be corrected for sensors. Same goes for medium and large format. I own the 5dIII 100mm 2.8 makro, 70-200 2.8 is II, 50 1.4, 16-35 2.8 II, I am super happy with the performance. They are all pretty new lenses. I mean the release dates are not that long ago. So is there some truth behind old lenses not being that good for digital backs or dslr? Again my boss told me the light might not hit the sensor in a perfect 90° angle with analog lenses what resolves in blur towards the corners. Even more extrem on wide angle glass. Is that true? Because if so, the lenses i mentioned aren't that old beside the 50mm, so they should be corrected for canon dslrs, right?

 

[Ryan708]

Your lenses should all give very good performane, along with the 5d MK III you have capabilities undreamed of 10 years ago! Even the 50 f/1.4 will be sharp if stopped down a bit, to 2.8+. Wide angle lenses do have a hard time at the corners of full frame cameras, but often that is not crucial

 

[Mt Spokane Photography]

Again my boss told me the light might not hit the sensor in a perfect 90° angle with analog lenses what resolves in blur towards the corners. Even more extrem on wide angle glass. Is that true? Because if so, the lenses i mentioned aren't that old beside the 50mm, so they should be corrected for canon dslrs, right?

That is certainly true, and always has been true, the light rays only strike the film / sensor at 90 degrees in the center. Digital has little to do with that.
Lenses are corrected to focus at the edges, but its never as good as the center. This has little to do with the number of photosites, its true for film cameras as well.
There is a issue with digital cameras that makes light falloff at the corners and edges worse, the photosites have depth to them, so the outer photosites are partially shaded and do not receive as much light as the grain at the outer edges of film. The signal from the outer photosites is amplified to account for this, and that creates more noise and less resolution at the edges and corners.
Generally, large sensors also have larger diameter photosites which helps compensate for the shallow angle. As the number of sensors increases, and the photosite size dimishes, the light falloff increases.
My explanation is likely confusing, its difficult to explain.
I believe your professor probably understands the situation well, but its a complex thing to grasp and teach.
There is some good reading at this site that might help.

http://www.cambridgeincolour.com/learn-photography-concepts.htm

Good luck, its always good to see a new member who wants to learn.

 

[CanikonLover]

Wow I'm happy that you guys answered on my thoughts! Thanks a lot!

Again my boss told me the light might not hit the sensor in a perfect 90° angle with analog lenses what resolves in blur towards the corners. Even more extrem on wide angle glass. Is that true? Because if so, the lenses i mentioned aren't that old beside the 50mm, so they should be corrected for canon dslrs, right?

That is certainly true, and always has been true, the light rays only strike the film / sensor at 90 degrees in the center. Digital has little to do with that.
Lenses are corrected to focus at the edges, but its never as good as the center. This has little to do with the number of photosites, its true for film cameras as well.
There is a issue with digital cameras that makes light falloff at the corners and edges worse, the photosites have depth to them, so the outer photosites are partially shaded and do not receive as much light as the grain at the outer edges of film. The signal from the outer photosites is amplified to account for this, and that creates more noise and less resolution at the edges and corners.
Generally, large sensors also have larger diameter photosites which helps compensate for the shallow angle. As the number of sensors increases, and the photosite size dimishes, the light falloff increases.
My explanation is likely confusing, its difficult to explain.
I believe your professor probably understands the situation well, but its a complex thing to grasp and teach.
There is some good reading at this site that might help.

Ok so I think I got what you said because of the light fall off a film would receive more light in the corners than sensor photosites would, so in order to compensate the camera sets the photosites in the corners a little more sensitive than in the center which also resolves in blur towards the corners. So the more MP a sensor has the smaller off course the size of the photosites and the more photosites gonna be amplified to correct the lightfall off. So more MP on a 36x24 size sensor resolve in a stronger blur towards corners?

Hello,
I have a 5d2 and have very similar set up to you.
I also recently bought an old Hasselblad with 150 and 250 lenses for shooting film. Though i did buy a Zoerk Canon adapter for the Hassey lenses to work on my Canon.
I did a resolution test on my 5d2 with the 70-200 f2.8 USM IS and the 150mm C Hassey at 150mm with a Zork adapter fitted to the Canon. I'll post some examples a little later as the hassy lens gave a slightly better colour rendition and sharpness.
Now this could be the copy of the 70-200mm is off or that I couldn't focus it properly but I set them both up via live view and f stop etc.
I need to try this again as this can't be right.
Regards
David

Great I'd love to see that studies. So if I got it right the Hassey lenses give better resolution because the image circle is way bigger and if you mount it on a smaller FF body the sensor will be within the sweat spot of the Hassey image circle. Same effect when you mount EF lenses on EF-S Bodys. Right?

 

[jhanken]

There is a issue with digital cameras that makes light falloff at the corners and edges worse, the photosites have depth to them, so the outer photosites are partially shaded and do not receive as much light as the grain at the outer edges of film. The signal from the outer photosites is amplified to account for this, and that creates more noise and less resolution at the edges and corners.

I read an interesting article about the new Leica M sensor that seems to better addresses the sensor depth issue. I the corners. I hope this is the direction for all the big DSLR makers over the coming years.

http://leicarumors.com/2012/09/19/the-24mp-max-sensor-inside-the-new-leica-m-is-mabe-by-cmosis.aspx/