How many megapixels = 35mm film?

What's the comparison in megapixels to film?

I'm looking at buying a 30D and want an indication of how sharp it is compared to a 35mm film camera.

Would 35mm film be 8.2 megapixels like the 30D is?

Next question is, how big can you blow up an 8.2 megapixel image before you start seeing grain? Like, what's an acceptable amount of blowing up? I'm just after an indication and a general idea.

I'm new to the digital world and any help with these questions would be appreciated.


-Frankie

 

It's not really possible to compare them easily. Why? Well, film enlarged using traditional methods is a chemical process which yields very subtle results. It's easy to compare a negative scan, but this can vary technology wise from about 2MP to well over 50MP, depending on how closely resolved the scan was.

An 8MP camera can print a shot quite large, but what is acceptably large is entirely debateable. There is a load of crap talked on various websites about how big a 300dpi enlargement is going to be. The simple answer I would say is that a 20D compares very favourably with 35mm negative film when enlarged to sizes of easily A3. I've done this myself.

I am aware that plenty of people have printed A0 and other "poster" sizes with smaller MP cameras happily. I've also seen shots which are awful at web size.... The individual picture makes a big difference!

Rob

 

I've had 8.2mp images enlarged to 30x20 and 30x10 (both inches) and on close examination you can see grain but you don't look at a picture that size close up - you naturally want to back off a bit. When you do that they look great.
I've done the same enlargement using my 6.3 Digital Rebel before I sold it and those results were great too.

Feel free to buy a print from my site to see for yourself!!!

 

its the sensor-size which makes the difference. 20 mp is approaching something like a 35mm neg.

 

Rob, I did a few A3 prints from my camera... 3MP and they are now exhibited. The quality is very good. I mean... I don't expect anyone to look at the photo from 5 cm distance... but it is framed on the wall and you won't notice artifacts from 50 cm.... So A3 is easily done here.... Actually from DSLR I expect something larger...

 

Nice.

 

You gotta try these things, Daniel!!
Worst that can happen is no-one buys.....best thing is i get a few orders!!

 

I was gonna say that actually... 10/10 for plugging your work Dave!

Rob

 

Cheers Rob!!
Still very few takers though..not through the site anyway. i have sold my California street shot 3 times though. Even another photographer appreciated it!!

 

I think it 20/30D approaches a properly developed ISO 400 film. Maybe ISO 200

But the difference is mostly practical. Do you want to shoot film or digital? What is the best medium for the job? How are you going to print film? What's the output?

 

Ok…..

First you have to keep in mind that the film in comparison to digital debate is a bit miss leading. 35mm film cannot be directly compared to digital in the usual ‘size matters’ account.

Depending on the grain size (ala. ISO speed) the comparable Mp count can range from 18-24 Mp for 400 speed film to what I have read (and there is some debate on this) to as high a 75 Mp for 25 speed film or slower. The problem is that the Mp count also derives on sensor sensitivity, actual vs. usable pixels, etc. If using some Tech pan, I heard of a comparable Mp count of over 100 Mp, (but that was debatable.)

Next you have to consider the ability of the sensor to reproduce the actual image. Regardless of the Mp count, the question comes into how well does the sensor reproduce the image. When the first DSLRs came out in the early 1990’s, (Nikon DCS) the images were only 1-1.5 Mp. Do a search on the internet on pics taken with this beast, and you will see what I mean. All the megapixles in the world wont help if the camera is lousy, but in a small Mp camera like the Nikon DCS, the images were great for what it was.

In addition, the other question is the print media. I don’t care if you have 2 speed ISO Pan, if you print the image on lousy paper, through a lousy enlarger, shot through a lousy camera, forget it. Your out of luck on image quality.

Remember silver Halide paper has microscopic grains of silver.

Ink jet printers shoot tiny dots of ink that spread. The silver halide paper will be MUCH finer than the ink jet.

Now, the same hold true for file sizes. If you set the camera up the right way, and save the image the right way, you can go as large as a road sign billboard and not see much grain. But remember that at that size, (and viewing an image up close is tuff for something large like a 20x30) the image grain will probably not be noticed.

For the 30D don’t worry, be happy, and shoot away and have fun making planet sized images.

In time you can afford a 20 Mp Med. format for the same price as a film MF is now. Then you are really talking.

 

i recently did a presentation on the myths and details of film vs. digital (35mm slide vs. 35mm or smaller digital sensors). In my opinion the ISO has littler to do with resolution that people think. For instance, I get the same detail (except much cleaner) with my 20d at ISO 400 than I can get with slide film at ISO 400 or 200 even. The issue is not just about megapixels. In past years, many film shooters complained that it would take a 30 or 40 megapixel camera to rival the resolution of 35mm film. However, over the past decade or so modern technology has progressed quite a bit and there are now several digital cameras that can consistently near, match, or exceed the pure resolution of 35mm film, even at low ISOs (for instance, nikon's d2x, canon's 5d and 1dsMKII).

One time I took some shots with my 20d at ISO 100 and immediately after took some shots with my 1n with the same lens using velvia (iso 50). The detail is cleaner in my 20d's images, and I actually prefer it's image quality. At this point, the resolution of 35mm isnt that much greater than popular 1.5/1.6 crop digital sensors, and there isnt a big enough difference to make resolution a deciding factor. The only thing that would make me want to shoot slides over digital is the larger color tone gamut.

You have to keep in mind that there is more to this issue than resolution, or else we'd all shoot 4x5. I think we can agree that image quality (and of course workflow and such, but I wont go into that) is the main 'subsection' on the debate. IMO, this is composed into 5 subcategories - resolution, color accuracy, color gamut, shadow/highlight capabilities, and grain/noise.

While film may have a slight edge on resolution (depends on the scanner used and the digital camera it is compared to), there are many other factors that go into what we view as a good photograph. As far as color accuracy, digital almost always takes the lead as the initial capture of digital is much more versatile than film. For instance, if you were shooting some landscapes in velvia in austria or something and saw some people that you wanted to take candids of, you might worry about using velvia because it botches skin tones terribly. This is partly a workflow or convenience issue, but it is still apparent that digital's capture is more versatile and accurate for color, even though there are types of slide film with good color accuracy. This is one reason why many portraiture photographers havent hesitated about switching to digital.

Color gamut and tonality goes to film. plain and simple. Even with 16-bit Tiff files in AdobeRGB or ProRGB and 32-bit HDR files, the color range (tonality ranges can equal or exceed slides in some situations) is almost always larger with slide film than with digital.

the shadow/highlight thing is basically split. Digital can capture more shadow details than slide film can, while film's highlight capacity is higher than digital's, and can capture subtle highlights that digital would just blow out. Neither is really bad at one or the other, just each has strengths and weaknesses.

Aside from possible color accuracy, one section of the debate that digital clearly wins is grain/noise. Digital is much cleaner than film. A digital sensor captures no grain at all (because the formation of the granular specs of film is a chemical process), but does have digital noise, which is slightly different. A digital camera (esp. that 30d, which has terrific noise capabilities) can capture cleaner images at ISO 400 than slide film can at ISO 100 (or even 50, depending on the film). However, in film's defense, the noise from digital sensors can be slightly more bothersome than film's grain because while grain retains a more gaussian spread, noise is more like tiny speckled splotches of color (which is only really noticeable at ISO 800 or 1600 and above).

Just keep in mind that it's not all about megapixels (resolution) nor sensor size as someone else mentioned (hence the d2x's capabilities). After all the research and comparisons I made while studying this topic, it has become apparent that when buying a dSLR such as the 20d, 30d, 350d, d70, d200, etc., you dont really need to worry about resolution. If the resolution of these cameras isnt good enough for you, chances are 35mm slides will dissapoint you also.

I'd say go buy that 30d, you'll love it. i've printed some large images from my 20d (16x24") and they turned out beautifully. I've come to a point where when printing orders for clients, no matter what sizes they order, I never have to worry about if my camera's resolution can cope. And that's what is important.