Telling film from digital ...

[dmr]

The conversation went kinda like this ...

Phone: Rrrrrringgggg {well, more like a cheep, but ...}

Me: Hello

He: Hey, those are some nice photos you have there!

Me: Uh, thanks {blush}

He: What kind of a digital do you have?

Me: Uh, none.

He: No way, I can tell, and at least some of those are digital!

{long back and forth about how he can tell because of the halos around the lights and such}

Me: Hey, I swear, everything on that page is film.

He: Well, ok if you say so, g'bye. {sounding very un-convinced}

🙁

The page we were referring to is:

http://www.letis.com/dmr/pics/vegas/vegas3/

... which I know I've posted here before. The one he *swears* is digital, "no way is it film" is the first attachment here, and one he swears is digital but he grudgingly admits may be film is the second one.

My question, how do people think they can tell, and can you really tell?

 

[Sonnar Brian]

After it is scanned in, it is hard to tell. It "is" digital. If you scan at max-res and blow up a small section, you can resolve the film's grain. That should do it.

Or just tell him, yes. It is a Digital Canonet QL17 G3 with a 30 Megapixel-equivalent imaging back and you always use raw analog format for capture.

 

[Kin Lau]

Easiest way to tell that it's digital... look at the EXIF header. Of course, just for the fun of it, you can copy it from a digital shot and mess with their minds by stating that it was shot with a fisheye when it's obviously a telephone shot or vice versa 🙂

Digicam's (not DSLR's or the Epson RD1) often have the "everything in focus" look due to the extremely large DOF because of the small sensor.

Other than that, I've seen most "I can tell if it's digital" claims fall flat.

 

[Fred]

A digital image stored on err.....film. That should do it.

 

[thpook]

The conversation went kinda like this ...

Phone: Rrrrrringgggg {well, more like a cheep, but ...}

Me: Hello

He: Hey, those are some nice photos you have there!

Me: Uh, thanks {blush}

He: What kind of a digital do you have?

Me: Uh, none.

He: No way, I can tell, and at least some of those are digital!

{long back and forth about how he can tell because of the halos around the lights and such}

Me: Hey, I swear, everything on that page is film.

He: Well, ok if you say so, g'bye. {sounding very un-convinced}

🙁

The page we were referring to is:

http://www.letis.com/dmr/pics/vegas/vegas3/

... which I know I've posted here before. The one he *swears* is digital, "no way is it film" is the first attachment here, and one he swears is digital but he grudgingly admits may be film is the second one.

My question, how do people think they can tell, and can you really tell?

The halos that he is talking about around the street lamps look like birefringence (commonly called chromatic aberration or purple fringing), but that doesn't necessarily mean that the shot came from a digital. If I had to guess, I would say that it came from a digital, or they are sodium vapor lamps (if I remember correctly, SV lamps cause a blue color cast on film. I could be wrong.).

 

[Nikon Bob]

I sometimes think that you can tell the difference even from a scanned neg. A straight digital image seems to be really smooth to me where a neg scan has some texture (grain?). Still, at best it is a 50/50 deal.

 

[Fedzilla_Bob]

But then, there is a digital equivalent to grain. It can be seen in a lot of digital images that are captured at ISO ratings of 400 and higher.

As for the halo, I'll bet that many lenses for digital cameras are based on the same geometry from earlier designs. It is possible that both analog and digital cameras can produce that same artifact.

Additionally image compression can add artifacts that look simialr to grain.

Viewing an image from a scanned negative or print that is displayed on a web page is a poor way to make a judgement.

 

[thpook]

For a digital equivalent to grain check out the attached. It is a 100% crop of a photo I took at ISO 1600 with my D70, and then converted to black and white using the channel mixer. As you can see, you can get pretty film like grain with the right processing but I don't think I could pass it off as film.

 

[vincentbenoit]

It's usually quite difficult, if not impossible, to tell between scanned film and true digital capture by viewing downsampled image files on a monitor screen. It would make more sense to compare prints.
From the 50 or so pictures on my website, can you guess which ones were captured digitally and which ones are scanned film?
http://homepage.ntlworld.com/vincentbenoit/

Cheers
Vincent

 

[Fedzilla_Bob]

As you can see, you can get pretty film like grain with the right processing but I don't think I could pass it off as film.

No, it would never pass as film grain. It is only similar. Also, the grain characteristics are likely different for each kind of CCD used by each manufacturer.

I have to say though, your example at 1600 ISO isn't as bad as some other examples seen. This probably shows how good the sensor is on the D70.

 

[jon_flanders]

Maybe some one can give me the definitive answer or point me to it. What is the digital camera equilent of 35mm and then of medium format.

I've heard various estimates. 12 megapixels for 35mm, for example.

 

[Kin Lau]

Maybe some one can give me the definitive answer or point me to it. What is the digital camera equilent of 35mm and then of medium format.

I've heard various estimates. 12 megapixels for 35mm, for example.

That's the problem... there is no definitive answer. Not all films are equal, c41 vs e6 vs b&w vs kodachrome etc. Then there's the question of colour vs resolution, and finally, there's the subject.

Compared with consumer c41, 6mp is probably there... I know I can crop way more out of a 6mp shot than a c41 scan. Trying to match Velvia or Kodachrome with the combo of colour and resolution probably puts us in 16-20mp territory. Trying to match Tech-Pan or Gigabit for sheer resolution, might put us into perhaps the 100mp range?

OTOH, it's much easier to blow up a 6mp shot from a DSLR than a film one due to the lack of noise.

 

[dmr]

What I'm gonna do tomorrow is to show up at his desk with the negative and the camera. He's really an ok guy, but a bit of a know-it-all concerning about everything, I'm sure you know the type. 🙂

Or just tell him, yes. It is a Digital Canonet QL17 G3 with a 30 Megapixel-equivalent imaging back and you always use raw analog format for capture.

LOL! He is gonna know that I'm showing him a very old film-only camera, though. 🙂

Let's see ... If you scan the negative at 4800 dpi you get {punching handy-dandy calculator} hey, about 30 megapixels, that's the number you must have used. Now if you scan it at 5600 dpi, which is the scanner I'm thinking of getting, you get, wow, like 39 megapixels! Yeah, that's the ticket. 🙂 🙂 🙂

 

[dmr]

That's the problem... there is no definitive answer. Not all films are equal, c41 vs e6 vs b&w vs kodachrome etc. Then there's the question of colour vs resolution, and finally, there's the subject.

What exactly would be the highest resolution color 35mm film today? Would it be K64?

I'm getting the impression that today's film scanners can easily out-scan most films.

 

[Bertram2]

It's usually quite difficult, if not impossible, to tell between scanned film and true digital capture by viewing downsampled image files on a monitor screen. It would make more sense to compare prints.
From the 50 or so pictures on my website, can you guess which ones were captured digitally and which ones are scanned film?
http://homepage.ntlworld.com/vincentbenoit/

Cheers
Vincent

Second your opinion, very difficult. Have been at your homepage btw, VERY nice photos there ! Chapeau !
Best,
Bertram
I#ll be in Paris from 20.6. to 25.6. 2005 , if you would like to meet me for a coffe comtact me off list ! --> betramfoto@bersac.de

 

[Gabriel M.A.]

The two attachments you have are both film. You cannot get that kind of nice shadow detail gradation with digital yet. You can get alecky and argue that it's all digital and that you're not even on the phone, you're on a glorified voice converting modem. 😉

It is getting increasingly difficult to tell each other apart, though, since we're scanning film (a pseudo digital picture) and digital is catching up (slowly) to film in the latitude gap. A skilled digital shooter can also merge two different shots (won't go into that rant) to get the whole luminosity range of the scene the way you could from a properly exposed film negative.

I think another reason he may not have believed you is that there is still this belief that any nondigital picture, specially a night shot, will have horrible film grain. Not necessarily so with a medium-ISO film in a rangefinder and a caffeine-free photographer!! (I guess it depends on the time of day)

 

[Tin]

Digicam's (not DSLR's or the Epson RD1) often have the "everything in focus" look due to the extremely large DOF because of the small sensor.

Kin - can you explain to me why this is so? This observation has been bugging me for some time now. In my own limited experience, that flat "everything in focus" look is less apparent on the monitor, but is very obvious when printed on good quality photo paper. But is the reason due to the small sensor or is it the shorter focal length of the lens that created that efffect. (Of course I understand that a shorter focal length is needed because of the small sensor, but the direct optical effect comes from the shorter focal length lens. That is how I reason it out anyway.) Am I right, or is there a better explanation?

If this reasoning is correct, then that effect should be gone if a full size sensor and normal focal length lenses were used. If it is still there, then it would not be an optical effect, but might be a digital artifact.

Tin

 

[peter_n]

Vincent, nice stuff! I wasn't interested in looking for the differences, but I liked your images a lot.

 

[Heath]

Tin (and Kin), I think the main reason for the 'everythin-in-focus' flat look has a lot to do with the aperture of the lens. Most compact digicam lens's ahve a relatively small aperture, unlike DSLR's, RD-1's and the more expensive prosumer models, such as the high end Sony's, Canon's and Panasonic's (which use Leica lenses).

If I am wrong, could someone put me on the correct path.

Heath

 

[simonankor]

I found my DSLR pictures a bit flat generally... I always put it down to lack of texture, and the difference in dynamic range. Occasionally one stands out but for the most part, the results are a bit dull.

Of course, this is all in my biased view... It could be partly cause I don't enjoy using the DSLR! 😉