Understand Grain v.s. Noise / PSed Blur v.s. Optical Blur

[tsienni]

Hello,

I've had these two technical questions for some time but the info I read from the Internet never really left me totally convinced.

So I ask:

1) What would be those distinguishing visual features, if any, that separate film grains from digital noise, seen on the computer screen?

Example: http://www.pbase.com/tsienni/image/83652824

Because I shoot digital, the noise you see is digital by origin. In the past I tried the image program NoiseNinja for correction, by which I know I can reduce the noise, but my real goal is not eliminating the noise, but rather through the post-treatment making the noise look film grain-like as much as possible. Is there a way to achieve this objective in lieu of actually shooting film?

2) What would be those distinguishing visual features, if any, that separate Photoshopped blur effects from the real optical blur, seen again on the computer screen?

Example: http://www.pbase.com/tsienni/image/77623643

The original is not out of focus, but I intentionally photoshopped the shot by the motion blur filter. Now I want to know how to conclude that the result is a fake if I didn't tell you I photoshopped?

I appreciate your spending time reading this. Hopefully I could get some advice here.

Thanks in advance.

// Tsienni

[sean_mcr]

Different film has different characteristics. So when people say how does noise compare to grain, well it very much depends on which film

Have a look at Matt webbers site

http://urbanphotos.piczo.com/?cr=1&rfm=y

it's obvious looking at the shots when he's changed film

Markus Hartel

http://www.markushartel.com/galleries/

How do you think the grain in your shot compares to the shots in the links, and how do they compare to each other?

It's second best to judge shots on screen, it's in print that the truth will out. But still it's pretty obvious to me, it would just be even more so in print

As for the blur

Let me ask you a question

Did you not find the scene interesting enough in its own right? and if not, are such scenes really worth shooting?

My own feelings on my own shot

http://www.pbase.com/sean_mcr/image/68695206

[jdepould]

The easiest thing to do is shoot some B&W film of a clear blue sky with your favorite film (preferrably a high-speed film), scan it and layer that over the picture, adjusting the blending and opacity to taste.

[tsienni]

Hi,

Thanks, you two, for the input! Although my intention has been to avoid veering into the old film v.s. digital debate, I guess some points are bound to show up in a discussion like this. Let's confine the talk to my original questions, because if it's about inspecting the grain/noise on a print work hanging on the wall, I have the impression the visual difference is by and large noticeable (but please correct me on this if I'm wrong), so in that case my question would simply be rendered moot.

Granted, the computer screen is the medium that led me to confuse grain and noise. If presented with a black and white photo on the net, I often feel the film version appears to me deeper, now here is the issue - I see the difference, but the difference is very subtle, I normally need to come back many times to two versions to form a viable impression. So what exactly caused this visual discrepancy? Is it psychological or are there verifiable physical traits? The thing is, when I say film photos look deeper, that's mostly an overall impression, but if I dig into any small part of the photo where the grain/noise is most conspicuous, and then you compare grain with noise, it's getting hard. I seem to have the sense that the grain looks more homogenious/uniform than noise, even "milky" grain in some landscape work I saw by film, but in practice, in general, I can't tell with all confidence.

Take that Matt Webber's site Sean mentioned, come here and have a look

http://pic1.piczo.com/urbanphotos/?g=17644612

Scroll down and the fifth photo. Sean, are you absolutely sure he's shooting film? To me, it looks like he used digital rather than darkroom manipulation. I dunno. Actually this is why I started and asked my question.

As for the blur, same question, if someone comes up and tells me, no, it's artificial, it's different than real motion blur in what and what way, I'll stop and try no more.

On that example photo, Sean, you asked. The original one is a copy of a painting, it made me feel dizzy at the spot, I thought if my camera falls down on the bench, the picture would pretty much summerize my reaction. I didn't let my camera fall, I come home and add motion blur in PS, yeah, that's what happened. I plead guilty.

I still don't know the answers, pls continue.

Thanks.

[madlights]

tsienni wrote:

I often feel the film version appears to me deeper,

I know exactly what you mean on this. I love doing black and white...but I too have felt the difference as you say. Ever since I've gotten digital I've thought this. I've tried adding grain...subtracting grain...working with contrasts and tones....but still have never quite got that deep look that to me film has. Everyone uses filters...burning, dodging etc. Thinking that even in photojournalism and documentary photos...that there's nothing wrong or dishonest in intent...with trying to get a good "look" to them...and somehow film has to me a better "look" in black and white. I've wondered too that maybe digital is too "clear" and it's the grain...but don't know. It's funny how the tones can be simulated for all different types of film...but digital still looks different and sometimes very attractive...but different. I remember when (and I'm dating myself here) the switch came to digital music and I could tell the difference...I can still tell the difference even at higher sampling rates than most people listen to...and my hearing isn't so good even (too much loud music and noise) but analog has more depth to me..maybe I'm full of beans...and then maybe we can really detect those little nuances that aren't there in digital...maybe we sense them...I don't know for sure...I don't even think sometimes that it's got much to do with density...since 'out of camera' B+W my old 3mp - 7 year old camera has a more 'film' look than my newer ones...even when printed...at least to my eye. Haven't figured that one out yet either.

[sean_mcr]

I know it's lazy of me, but it puts it far better then i could



http://www.luminous-landscape.com/essays/not-film.shtml

[madlights]

That's a good article Sean...but even "on screen" without printing and even at least to my eye when film is printed on an inkjet...I mean I've spent a lot of time trying to get the same sort of look as Tri-x (even close would be OK). Not that it's always better...a lot of times it's not at all. Digital is much clearer...as digital music is clearer and cleaner than analog. It's just trying to "replicate" the look. Not arguing between since there to me isn't an argument...just a difference. I agree that each has it's own strength..and one of course is chemical. It's just that somewhere there may be a key to get that "look" of film...or more so...much as a lot of musicians are now using older tube amps etc. to get a fuller sound even when recorded digitally.... Of course there may be a "Unified Theory" formula that explains the universe too and maybe I'll have as much luck trying to find that...I can't understand either myself the "arguments" between if one is "better" than the other. It's just that one may be different..there's a lot of films that never appealed to me in look. I never much liked Velvia slide film or even Provia for example...but that's a generalization on my part...I've seen beautiful shots from those (just not mine)

[tsienni]

Once I was in a music hall where some like-minded people gathered and improvised on experimental music stuff. They were making sound by glass bottles, keys, even chairs - it was real NOISE. I still remember the banner they hang on the wall, it reads "no sound is innocent". I guess it's true much depends on the school of photography one adheres to. "the amazingly 'clean' images", hehe, commercial posters are most clean looking, are they innocent?

off topic, Sean, where did you first learn Matt Webber and Markus Hartel's sites, if you don't mind I asking. Where to find similar work by other photographers, do you know? Thanks!

Have a nice evening.

[sean_mcr]

I've been a fan of webber for years (have his book actually), that's how i found out about Markus


I might have shown you this before

http://www.in-public.com/


Markus has a download here for a couple of $

http://www.markushartel.com/tutorials/p ... files.html

But what i think really matters is here (it's worth reading)

http://theonlinephotographer.typepad.co ... ldi-w.html

[tsienni]

Quite articulated in the last link. Looks like Mike has a fan base - I spent some time going through all those differing views in the comments. From noise problem to consumer choice dilemma, pretty much has been said.

I had that in-public link, but haven't checked back for long. Like many other blogs, once I saw something interesting on internet I normally will bookmark, but after a while I always tend to forget. This is the reason I'm more used to browsing forums, I expect to see new stuff, new people in a basically level playing field. It's a shame our Pbase forum doesn't always function, since I joined I come to realise there're actually many gifted photographers on this site, but only in very few occasions I found them through the forum threads. Though I seem to understand why they don't come here, it's still a pity because forums are very good effective communication venue for exchanging ideas. But then it can be argued it's almost the same everywhere, not just on Pbase. Besides, when I spend too much time on Interent, this just reminds me I should go out and have more real life, which is more important.

Cheerio, and thanks again for the talk.

[sean_mcr]

Mike's got to be one of the top five writers in photography today.


He was Editor-in-Chief of PHOTO Techniques magazine for six years. Had a monthly column in Black & White Photography (a uk mag)

http://www.thegmcgroup.com/item--Black- ... 003BW.html


not to mention his "sunday morning photographer "column on luminous landscape

http://www.luminous-landscape.com/columns/sunday1.shtml

[sean_mcr]

I have to look at a lot of prints and own more books on photographers then anybody i know. I keep meaning to do a review of some of them but i'm much more at home with a camera then a pen, i'll get around to

It was my Birthday on Monday just gone. I could have had a few grands worth of camera gear (we go all out on Birthdays) I could have had the new digital Leica

But i sat down and thought about what was it that made me want to take pictures in the first place. What was one of the few things that could keep me quite. Well actually there are two things and that's looking at photographs and taking them. So i bought seven books to add to my ever growing collection. Sat down and looked through the images and i knew there and then that i didn't need new camera or lighting or anything else other then a simple reminder of why i loved photography


This was the closest i got to leica (shot on my Birthday) and has about as much depth as i'll ever need.

[madlights]

It does sort of seem that film grain is sometimes more uniform in a way...and digital noise, especially if it reaches certain levels is sometimes more "blotchy" looking...in getting back to the original topic... That is chromatic noise I mean...as opposed to color noise..Seems like film grain is sometimes to me, more uniform across the whole picture too, rather than only in the darker areas...at any rate film grain seems more unifying "sometimes". I used the word "seems" and "sometimes" a lot.... since not really positive about any of this. Even it seems different digitals have different patterns to the noise...or different looks (guess films do too). Some more 'even' and some more 'blotchy' even at similar levels of noise...but also find it really hard to always tell. It's so strange too that grain has been part of and even a strength of film...and that in digital, even at very low levels, has been seen as a scourge. (not that it's seen that way by all always, including myself) Knowing I don't see the volume of pictures some do..it's just my impressions...since wondering this for a while too.

[sean_mcr]

tsienni,


Matt shoots with a Lieca , you're looking at film


The thing is is about the blur is if it made you feel dizzy, can't you convey that by showing us what you actually saw?. If something can actually make you feel that way is it not worth showing it as you saw it?

[tsienni]

Sorry sorry for late reply, but I've been kept busy for a while.

Barri, to be precise, are you talking about the chroma noise visible in mid-tones? My digicam very easily heaps those patches of smear-like smudges over ISO 400, I don't even need to underexpose by 2 stops. so when I think this over again, hum, I really should recognise the digital noise without a problem based on my shooting experience.

After I read all the stuff in this thread, I have this idea. Well, why not go with Canon, almost noise-free till ISO 800. And in case someone wants the grain, just blend the film grain layer to the picture, this way the photographer have the control and flexibility, no?

This connects to the second question, similar to adding the noise, you can also add blur in Photoshop, all can be done in post-treatment. I guess the tricky part is you still need to make a decision on how far it goes. Is it 80% percent opacity or higher, or how much degree for the gaussian blur, questions like that. This in a sense returns to reality, because you don't want to overdo your photo. Easier said than done, it's always a delicate task to decide where to stop in Photoshop, but seen in another light, this is also so practical - myself I rarely can get everthing perfectly right just at the moment when I clicked the shutter.

Oh, yes, I wonder if I shoot a Leica, all these puzzles will instantly go away and I only end up with sharp details + beautiful soft dofs, ie, Leica outlook in my photos???? So, Sean, if I were you, I'll buy less weighty picture books (aren't they a burden if you move to a new apartment?), but save the money for one pocket-sized Leica!!!

Cheers