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"3D" effect?
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PostPosted: Thu Jan 13, 2011 12:12 am    Post subject: Reply with quote

I would think not 3D.
But: I have not the ability to make a safe discrimination between 3D pictures and "flat" pictures. Probably it is too late in the evening to see 3D Smile


PostPosted: Thu Jan 13, 2011 7:08 am    Post subject: Reply with quote

ZoneV wrote:
I would think not 3D.
But: I have not the ability to make a safe discrimination between 3D pictures and "flat" pictures. Probably it is too late in the evening to see 3D Smile

I tend to agree. I can see the 3D effect with stereo images but from a single flat 2D image I'm at a loss as to how it can be 3D.


PostPosted: Thu Jan 13, 2011 10:21 am    Post subject: Reply with quote

Sometimes I see a kind of 3D (not real 3D) in an flat image - but in most images in the thread I see none of that. In some images I see a bit 3D, but not reliable.


PostPosted: Thu Jan 13, 2011 11:11 am    Post subject: Reply with quote

I find this a very good example of perceived 3D. It's a short movie clip shot with the SMC PENTAX 1:2/28 (same as the Zeiss Distagon "Hollywood").

http://vimeo.com/7028401


PostPosted: Thu Jan 13, 2011 11:16 am    Post subject: Reply with quote

Here's the image (a photo I took in Lucca) that I post whenever there is a thread about "3d" Laughing

Distagon 2/28 on 5D


I choose this image because it breaks a couple of myths about 3D effect:

1) that it has to be wide open - as you can see, this photo is not. You have to go very far into the background to see a noticeable blur;

2) that it needs strong directional light - as you can see, here the day was overcast and dull and the light had no direction (and no shadows) what so ever.

What surfaces from the analisys of this photo, is that we have 5 different planes:

A) Foreground (the ad stand)
B) 2nd foreground (the car and street lamp)
C) middle ground (the bike and stop sign)
D) background (the trees and busses)
E) far background (houses in the distance)

The central foreground element (ad stand) creates two perspective "fugues": one at the right, the strongest one due to the many visual elements, that follows an imaginary path that goes through the "wings" provided by the ad stand, street lamp, bike, stop sign, first tree, second tree. These elements are placed alternatively (left-right-left-right-left-right) which creates the feeling of the imaginary path.
The other, weaker, perspective fugue is at the left, and follows the main road. The reason is weaker is because it has less elements of interest and also because the blue bus blocks the view in a crucial point.

As we learned from school, the perspective in a 2D image helps creating an illusion of depth. but what it does is, it mainly provides the proportions that make the scene realistic. To be really 3D, to "pop", as they say, the drawing, that is the way the elements are represented, is crucial.

And here is where the character of the lens comes in.
I always found that lenses with a smooth bokeh provide less pop and "3D" than lenses with a busier bokeh. Not super busy (as it would be distracting), but "lively" enough to create the feeling that we are still looking at a real object (although blurred) and not at a painted blur or "wash".

Another important feature is the microcontrast, that is the ability of the lens to differentiate between the smallest light-dark transitions in an image. Microcontrast is 50% of what we call "sharpness". The other 50% of sharpness is resolvance (the amount of information that is recorded in a given unit of flat photo space). For sharpness, both elements must be present. But for 3D, the resolvance is not that important. Microcontrast is what counts.
A good example of why microcontrast is important for 3D, is the bike.
In this photo, the bike is in the middle ground. The distance from the shooting point and the relatively small size of the bike make it impossible for it to have a lot of detail displayed. But what counts for the 3D effect is not that all wheel rays are rendered. What counts, is that what is rendered of the bike stands out clearly from the image plane following it. And this happens well here because the Hollywood lens has an excellent microcontrast.

The aperture, as we can see, does not have to be wide open. Actually, I find that on the contrary, in most cases wide open makes 3D more difficult. The reason is that wide open tends to give detail only to the object in the foreground, while all the following image planes (we have counted 5 of them in this photo) tend to end up equally blurred - so for instance in this scene the background and far background would look uniformly blurred with no distinction, and the middle ground (bike, stop sign) would lose a lof of the microcontrast benefit, because the higher blur caused by the wide open aperture would smear the smaller contrasts into a larger more confused image.

The key of 3D perception in an image is to provide the image with the right amount of differentiation between the different image planes. This is up to the photographer. The photographer must be able to "read" the scene and understand which of the available apertures will give him the most differentiation between the different image planes.

Another element that is important in 3D perception is the so called "curvature of field" of the lens. This is not very evident in this image. To be evident, we should have a near foreground object that has some important depth (like an automobile seen from the front or the back) and that takes at least half of the frame, from the centre to one edge.
In my photo, the ad stand is too small and not enough deep to illustrate the curvature of field visibly.
Technically speaking, curvature of field in a lens is a defect. A shortcoming. It means that the lens does not represent with an equal amount of focusing two points that are at the same distance from the lens but in different places of the frame.
Most fast lenses have some curvature of field. But some have more than others. Being strictly related to the spherical aberrations, Zeiss lenses tend to have more curvature of field than Japanese lenses, for instance. This because the "philosophy" of lens building at Zeiss privileges a classic optical design, that uses only spherical elements and corrects the aberrations through the use of expensive optical glass and the careful design of the optical elements. Japanese lenses, instead, tend to use a lot more ashpherical elements, which are able to correct the aberrations without the need to resort to expensive optical glass formulas.
As a result of this philosophy, the fast lenses in the Zess catalogue tend to have a significant and visible curvature of field at wide open apertures. Curvature of field attenuates as the iris is stopped down, but in fast lenses there are usually some traces of it also in the range of the first two or so stops after wide open. This is the reason why I often use apertures that are between 1 and 2,5 stops after wide open when I want to give the most 3D effect - of course, the choice must also take into account the scene and how the elements of the scene are placed, like I described above.

I hope that I have described sufficiently what is my own perception of 3D in a flat image and which are the "rules" that in my vision help to create it.
In this image that I posted, there is no objects that strikingly "pops out" of the scene. But if I imagine that my eyes are my feet, and if with them I imaginarily start to walk the sidewalk on the right, and move through it, passing by the ad stand, then the street lamp, then the car, then the bike, then the stop sign, then I cross the road and reach the trees, then farther more and I reach the busses... if I do that path with my eyes, I can clearly perceive, as I go through it, the distance and the "air" between the elements.

That may be subtle, and perhaps not apparent for everyone, but that is when I call a picture to have the "3D".
_


PostPosted: Tue Apr 05, 2011 3:28 pm    Post subject: Reply with quote

Look at this post in a German forum.
Amazing!


PostPosted: Tue Apr 05, 2011 3:33 pm    Post subject: Reply with quote

LucisPictor wrote:
Look at this post in a German forum.
Amazing!


Yes, good one. Smile


PostPosted: Sun Apr 10, 2011 10:55 pm    Post subject: Reply with quote

I've noticed how colour can make a subject pop:-

BC1 and Praktica CZJ 28mm


Canon FDN 200mm f4


PostPosted: Mon Apr 11, 2011 12:39 pm    Post subject: Reply with quote

Yes, colour and contrast definately help.

I shot a roll of CF yesterday with my Meyer Optik 135/2.8 and was amazed by the pop! I think the bright sunshine helped Smile

Nice samples BTW!


PostPosted: Mon Apr 18, 2011 12:19 pm    Post subject: Reply with quote




1958 elmar 90 F4


PostPosted: Wed Apr 27, 2011 3:00 pm    Post subject: Reply with quote

This also shows a nice 3D effect:


Zeiss Distagon 1.4/35 @ EOS 5D


PostPosted: Fri Apr 29, 2011 11:23 pm    Post subject: Reply with quote

LucisPictor wrote:
Look at this post in a German forum.
Amazing!


Excuse me, Lucispictor. But I find the image with very confuse background and a limited tonal range.

I think that with a more out of focus backgropund and more tonal separation, the 3-D effect was more strong.

I guess that the tree could be more sharp to benefit the effect.


Rino.


PostPosted: Thu Jul 28, 2011 8:53 am    Post subject: Reply with quote

Hello there everyone,

First post for me here, and I think this picture might contribute to this post as I think it shows nice 3D effect.



I particularly agree with Orio post about 3D, I think small aperture will give you less IF and makes you think it's 3D whereas it's only the DOF effect and hier apeture will just help idstinguish what's really in focus and fade smoothly OOF and that (+the composition ) will give you 3D effect.

Also to note there are a lot of Zeiss lens in this post or other post regarding 3D effect it's really impressive, Wide angle or short tele but really lots of Zeiss.

Sorry for my english I'm a french MF fan Smile


PostPosted: Thu Jul 28, 2011 9:43 am    Post subject: Reply with quote

Nice photo of the cat. What lens did you use?

Welcome to the forum, Lordcamel. Perhaps you can introduce yourself a bit at the Photographer's Cafe forum.


PostPosted: Mon Aug 01, 2011 8:30 am    Post subject: Reply with quote

Thank you, I ll go and introduce myself asap.

The picture was taken using a D700 and 24 2.8 AF lens unfortunately it is not a manual focus lens, and I didn't focus manually on this one (as I was already crouching) ... but I wanted to show some 3D effect so .. Smile


PostPosted: Mon Aug 08, 2011 3:03 pm    Post subject: Reply with quote

Is Zeiss 50 1.7 considered a good performer for "3d effect ?"

I'm testing lots of 50 mm lens to see which one suits me best and I need to test one Zeiss lens, and this one seems tack sharp, got the zeiss look, hope it has the zeiss 3d too


PostPosted: Mon Aug 08, 2011 3:07 pm    Post subject: Reply with quote

Lordcamel wrote:
Is Zeiss 50 1.7 considered a good performer for "3d effect ?"


http://forum.mflenses.com/contax-501-7-wo-5dii-t28244.html


PostPosted: Tue Aug 09, 2011 9:26 am    Post subject: Reply with quote

Guess the answer is Yes !


PostPosted: Tue Aug 09, 2011 9:36 am    Post subject: Reply with quote

Remember, you need a series of other factors, not just the lens.


PostPosted: Tue Aug 09, 2011 9:41 am    Post subject: Reply with quote

Ofc , just looking for cheap lenses that can contribute to getting this 3d effect


PostPosted: Tue Aug 09, 2011 9:50 am    Post subject: Reply with quote

Orio wrote:
Remember, you need a series of other factors, not just the lens.

+1, you need a 30:f1.2 on aps-c and a 25:f0.85 on m4:3 to make those pics


PostPosted: Tue Aug 09, 2011 9:56 am    Post subject: Reply with quote

poilu wrote:
Orio wrote:
Remember, you need a series of other factors, not just the lens.

+1, you need a 30:f1.2 on aps-c and a 25:f0.85 on m4:3 to make those pics


I don't think I understood your statement very well ..

3d shots don't need 1.2 or 0.85 aperture ... nor a 50 mm equivalent lens


PostPosted: Tue Aug 09, 2011 10:09 am    Post subject: Reply with quote

Lordcamel wrote:
poilu wrote:
Orio wrote:
Remember, you need a series of other factors, not just the lens.

+1, you need a 30:f1.2 on aps-c and a 25:f0.85 on m4:3 to make those pics

I don't think I understood your statement very well ..
3d shots don't need 1.2 or 0.85 aperture ... nor a 50 mm equivalent lens

I mean to make the same pics as in the 50:1.7 thread
while it is not necessary to use wide open to produce 3D look, using f8 on a p&s is the best way to kill 3D
check faq for crop to find conversions rules


PostPosted: Tue Aug 09, 2011 10:17 am    Post subject: Reply with quote

I really don't see your point sorry I 'm missing something Smile


PostPosted: Tue Aug 09, 2011 10:33 am    Post subject: Reply with quote

Lordcamel wrote:
I really don't see your point sorry I 'm missing something Smile

mon commentaire souligne l'importance du senseur dans la tridimensionnalité d'une image
mes images avec le 50:1.7 offre une atmosphère qui nécessiterait un 30:f1.2 sous aps-c et un 25:f0.85 sous m4:3 pour être reproduite
vu que tu utilise un D700, format 35mm, ce commentaire n’était pas adressé a toi mais plutôt un avertissement général