Full Frame vs. APS-C Sensor - Do you really need to upgrade to Full Frame?

[Derrel]

As to what megapixel size is equivalent to 35 mm film, over the years I have read differences of opinion. At one time many people seemed to think that 6 million pixels was about like most 35 mm slower speed slide film. Back in the days of the EOS 10 D a friend and I looked at studio lighted portraits that we had shot and we both felt that the 10D offered finer resolution of detail than 100 ASA color negative film from the 1980s. Specifically we were looking at a young toddler's eyelashes and eyebrows… We each felt that we could see more detail in the individual hairs of the eyebrow than we could see with 100 ISO 35mm color negative film. I personally believe that today's 24 megapixel APS-C sensors offer better resolution than did 35mm film, and I feel that the Nikon D800's 36 megapixel sensor offers resolution of fine detail about like 6 x 6 cm 100 to 160 ISO color negative film from the 1980s. Some film offers incredible fine detail: for example 4 x 5" color transparency film offers incredible fine detail, and I think that for fine detail resolution 4 x 5" transparency film is better than digital medium format of 100 megapixels.

Speaking of film: how are we using film? Are we scanning it with a desktop scanner? Or are we drum scanning it with a $10,000 Imacon? Are we taking film images and wet printing them?

What size of a piece of film are we talking about? A few years ago I saw a photograph of a rose garden, and it was shot with film of various sizes and with various digital cameras.The film was able to resolve individual rose blossoms in the garden, whereas the digital images could not resolve individual blossoms from a distance of roughly what looked to be about 30-40 meters. The issue in my opinion was one of the target. For example, many times we see comparisons of film and digital when a lens type test chart is photographed at roughly 100 times or so of the focal length of the lens, which is really not that far away, and most digital systems do pretty well. However in the above rose garden test, film did surprisingly well, better than most digital systems.

In the early days of digital imaging small scale close-up scenes looked pretty good on digital but large scale or landscape scenes looked poor.Today this is not really the case, as we now have access to 24 to 100 megapixel digital images with small format high-grade lenses that are capable of resolving extremely fine detail. A strange peculiarity--for many years,has been that small format lenses such as those for 35mm systems are capable of resolving very fine detail, whereas lenses designed to be used with larger film formats such as medium and large format do not need to be so bitingly sharp. We have to look at both the lenses and the film or digital format size. Resolving power and sharpness is dependent upon both the lens and the capture medium size.

My feeling is that today's 24 megapixel sensors are better than medium-speed 35 mm film, and are about equal with 100 ISO 6 x 6 or 6 x 7 transparency film.

The biggest issue in today's world is getting the most out of a piece of film… Many people are using desktop scanners which are not really, in my opinion, fully capable of getting the most out of a piece of film in most cases. Other people have access to really good scanners like the Fuji Frontier, or the Imacon drum scanners.

 

[Original katomi]

Thanks at last a answer. I have been asking this question since getting a 4mg camera and no one seemed to know.
I used to use fp4 pulled to 100 asa/iso now use canon 6d,7d and push those to the limit. I look at reviews and specs of ff cameras and put off moving to ff. for what I do I think that if I change it will have to be to digital med format something like Pentax 645z I just don’t know enough about digital med format to know if I am looking that the wrong thing.
Your post may have just given me the answer, thanks.

 

[Derrel]

in today's market we have 50 and 100 megapixel "medium format" cameras which use sensors that are approximately 43 x 33 mm in size, and these cameras are most common from Pentax and from Fuji with I believe sensors made by Sony. This is not the same as the older "medium format". with the advent of 47 megapixel cameras from Sony, and from Nikonand 50 megapixel cameras from Canon, we now have a situation in which the upper end of the DSLR has arrived at the mega pixel count of 10 roughly $10,000 cameras from Pentax and from Fuji, with their GFX line.

A few years ago I read a very interesting piece by noted Internet photography writer Ming Thein , In which he compared a high megapixel Nikon with a high megapixel Pentax 43 format camera. Basically the Nikon was easier to shoot, and had almost exactly the same resolution despite shooting to a 3:2 format , While the Pentax shot to the standard 4:3aspect ratio.

let me summarize his exhaustive comparison by saying that a digital single lens reflex has better handling, is less demanding of being used on a tripod, and has more lenses to choose from, and has better auto focusing.

in digital single lens reflex camera models from Nikon and Canon, one can also find many third-party lenses of extremely high-quality such as those made by Zeiss, Sigma, and also a lot of lens choices are offered by the respective camera makers. in digital medium format there are very few native mount third-party lens options, although the Fuji GFX has proved itself extremely popular with using adapted legacy lenses of many manufacturers, made easily possible because it is a mirrorless design. in terms of being adaptable to many types of photography the digital single lens reflex from Canon or Nikon has many lenses available ranging from 800 mm down to roughly 14 mm in full frame, as well as a few exotic fisheye lenses. I expect within a short time that Canon or Nikon will offer a 60 megapixel digital single lens reflex or mirrorless camera,which will make it less necessary to go to a medium format camera, and which will leverage the tremendous lens system development that both Canon and Nikon have made over the past 30 or so years

 

[Soocom1]

The new Phase One back (a billion plus $$) has a sensor that is 53.7×40.4mm. That's creeping well into the original 120 format size. (60x45mm) 645 or 6x7 (60x70mm) and thus the resolution that is derived from the 10 and 12 Mp cell phone cameras put into such a large format gives of an equivalate resolution somewhere around a 12 speed ASA film.

Typical silver halide crystals can range from 1.0-1.5 microns in actual size.

Typical APS and FF sensors are typically hitting around 2.5-3.5 microns and many of the Med. Format sensors fall into the "fat pixel" category of around 5-9 microns in physical size.

Keep in mind that in the film days, 100 ASA had the same size silver crystals from 110 film, to 4x5 LF sheets.

So comparing format size in film is a near prefect apples to apples comparison.

Digital is governed by two primary aspects:
1: Physical restrictions in manufacturing and the eventual physical "wall" that the system will hit once the physical capabilities of the material making the sensors up is actually reached.
2: Cost. Making smaller and smaller pixels requires even more elaborate manufacturing techniques. And until the day is reached where we move away from the pixel process, we will be stuck with that.

This has already happened in some part with micro processors in computers and why were not seeing huge leaps in clock speeds and the like with newer computers.

The newest Fuji and Hasselblad offerings are hitting around the 2.5 micron mark and rumor has it that someone is trying to push the MF stuff into the .75-1.5 micron territory, giving an equivalent of around 300+Mp of actual resolution.

The H6D-400Mp Hassy monster is actually set up in a fashion giving the 400Mp resolution based on "overlapping" the pixels in a fast multi-image system. This is a throwback to the early post scan days of digital, just advanced and much faster.

100 speed ASA/ISO film hit a crystal size in that 1-1.5 micron size, BUT there is another factor:
Pixels are arraigned in a gridded and typically rectangular layout where literally they are packed in like graham crackers laid out flat in a box.
All nice and neat with the distance proportional to each other and whatever gaps exist do so only because of mechanical necessity.
The crossover from one pixle to the next is what creates the "pixlization" effect of a not so neat round object with the typical "stepping" of what should be a neatly round edge.

Now imagine those same graham crackers crushed up and laid out in the box with a hell of a lot of gaps between them, are asymmetrical, and vary in actual size from one to another with different shapes including tabular, granular and spherical. Except they are suspended in an emulsion that is subject to heat, warping, shrinkage, decay and all of them sit at different distances inside the emulsion.
Add in light issues including the CA, various types of distortion, light cancel-ization, and other factors and voila, digital hold a very real advantage over film even in lower resolution/older cameras.

THATS film!

It is also why cell phone cameras have a distinct advantage over other cameras in the "idiot proofing" aspect.

The only real "advantage at that point is if the film crystals are laid out and compacted together, then the smaller granular crystals "fill in" the gaps between say the tabular type and pick up detail in a more "natural" manner than a grid.

Film has the specific DISADVANTAGE of where if the crystals are too small they are not sensitive enough to record the light.
The limitation also includes multiple layers of emulsion that will dramatically reduce the amount of light transmission.

There is a yellow or green, blue and red layer in film, and those emulation layers takes up distance. The layers are in fact layers that contain dye in them that also take up thickness and absorb light.
The pixels in digital sit at exactly the same plane and thus have NO distance issues to record the color.

 

[Original katomi]

Hi just read and re read last nights posts, that plus my pro cons list I am staying with my canon, I have a way of getting the large pics that I want. Plus if this just a passing fad I don’t want to be spending mega cash.
I change my photography topics every few years, street photography, UV/ALS photography, table top and now large panos. More I look more I think I need to stay with the canon at least until I know what the next style is going to be.

 

[Solarflare]

Typical silver halide crystals can range from 1.0-1.5 microns in actual size.

Why, there is of course no such beast as a "typical crystal size" for film.

How large the crystals are depends a lot upon the film type.

High ISO films will have quite large crystals, low ISO films much smaller ones.

Microfilm for example, which is ugly colored monochrome extremly low ISO super high resolution film, has correspondingly tiny crystals.

 

[Designer]

I just watched the video, and I noticed that he claimed to compare ALL differences between the two sensor sizes, but did so only for image circle size and resolution. I think there are other differences, some of which are quite subtle, but possibly worth consideration.

So if crop factor and resolving power is everything, then your decision will be easy.

Much like selecting a lens based only on the focal length and nothing else.

 

[Original katomi]

The last time I used film they had just brought out the T grain 1000 ASA film it was meant to give an even grain on the film

 

[ebyelyakov]

Comparing film vs digital sensor. We need to take the Bayer Array Filter into consideration. With the colour film there are three layers, each responding to its portion of the spectrum. With the digital sensor - a flat array or colour blind pixels (out of which 50% are covered by Green, 25% Red and 25% Blue filter, provided it is Bayer) that are only capable of accumulating and registering a finite amount of the electric charge. And here is another limit -- Well Capacity (WC). The smaller the pixel, the less the WC the smaller the tolerance until the pixel burns with "255". I personally doubt the pixel pitch can go much down to what Sony is pushing with its latest sensor on the RIV, unless the smart people come with idea on continuous readout during the exposure to work around the Well Capacity limits.

 

[Solarflare]

Err yes you only get a finite signal.

Thats not a difference of digital compared to film.

Film also only gets a finite signal, obviously.

Noise to signal will be better on digital because digital has higher efficiency.

Unless you make a longterm exposure. Then digital can only keep up if you cool the sensor. Otherwise the noise of the sensor heat will destroy the advantage of the higher efficiency.

I dont think your "refill the photo diode during exposure" idea works. Its at very least not a general solution, for example it doesnt work with flash, or when photographing lightning.

 

[ebyelyakov]

Isn't film's equivalent to the "well capacity" better compared to a digital sensor? Provided (speaking of colour) it has three layers responsible for the individual layer's own part of the spectrum whilst the sensor has to do with just one "layer". So, my understanding it would be "unfair" to compare sensor pitch to the size of the particle on the film (especially considering they differ according to the ISO sensitivity of the film). This was my deliberation on the topic of a smaller pixel pitch and, as a result, an even greater resolution, that I personally do not believe can go much further..

Obviously continuous read of the sensor would be a utopia, especially when strobes are used (this the need to mechanical shutter as some Sony mirrorless shotters know)

And then yes, going back to the OP question, it makes reason to go to FF over APSC -- larger die allows for larger pixles, meaning better well capacity, less noise and so on.

 

[Original katomi]

Like all things the limits will be pushed until it hits the wall whatever that particular wall is.
Computers, broadband, cameras all things push the limits of the tech that is available at the time.
Then after a time things change or someone finds a way round the limits
A survey in the early days of home computing record that most homes would only need 1 computer.
I pads were the realm of Star Trek. I can see everyone reading this having a mental count of how many computers they have, ps your DSLR counts as well

 

[ebyelyakov]

I'm old enough to remember and having worked with the PCs that had 640kb of RAM (actually even less but that's not the point), -- more than enough for anyone as, some claim, was said by Bill Gates.
Based on my extensive read and painful interpretation of Roger Clark's articles on his web-site - we got a number of limiting factors and I do not believe, with the current technology we can venture much further.
Sensor requires a lens to service it and the larger the sensor area, the wider/larger the lens is required.. And wise versa. Plus re actual resolution the lens itself.

Can the pixel pitch be reduced much further? I doubt it. After pixel pipping a lot at the newly release Sony R4, it stands OK in the studio conditions but then, as the ISO increases, the noise becomes a bit too much to my liking with the quality becoming worse compared to the R3. I'm keenly awaiting for more real life uses, by people, outside well controlled studios to see how things will roll out.