My sharpness dilemmas

Ciel_Rouge

Hi everyone, this is my historic first post in this forum

I am a total beginner in the field of digital photography.

Anyway, I recently had an opportunity to view a bunch of group photos taken in 1930s. And what I found rather striking, they were literally RAZOR sharp. The persons and faces were very small as there were quite a few of them and the picture size was close to a postcard. Still, I could almost discern individual hair in their hairstyles, their eyes and facial expressions and the edges of each face were also razor-sharp.

Now, for the past few years I have been occasionally using a simple point-and-shoot and what I could notice was heavy blurring. So I have taken a closer look at online reviews and sample images, for example:

http://www.photographyblog.com/revie...sample_images/

And from what I can see there, even the latest DSLR produce a kind of "pixel soup" and the sharpness when published in print or online seems to be coming from reducing their size and even then, that "sharpness" appears sort of lame compared to what I saw in the 1930s photographs. So, please tell me, what is going on? Since I am a total newbie here, I might not understand some issues. How do you define sharpness? Is it true that all digital cameras produce a "pixel soup" as opposed to "razor-sharp" images?

ziggy53

Without seeing some of the images to which you refer I can only speak to what I know. Modern digital-SLR cameras do have a filter in front of the imager to prevent "moire", which can occur because of the regular organization of pixels in a digital camera plus the regular organization of some subject matter. As a result, digital images need particular sharpening to counteract the Anti-Alias/blur (AA) filter on the imager.

The higher the pixel count the less relevant the AA filter to smaller images, like small prints and Internet/computer viewing, but most people really do desire additional sharpening for those applications.

In the older "analog/film" world, moire was not an issue because of the random structure of the film grain. Printing also increased both local and global contrast, increasing apparent acuity. Printing small from a larger digital image generally also requires little sharpening for this reason.

If you compare P&S cameras with a dSLR one thing of note is the size of the imager and the effect on Depth-Of-Field (DOF). DOF in most P&S cameras seems greater than in most dSLRs as a result. This, in turn, results in less control of subject separation from the background using even large apertures in a P&S.

As an example, please review the following images taken with a crop 1.6x dSLR camera body and large aperture zoom at large aperture:







Pixel sharpness is rather good even in a crop at 100% (note hair and skin pores):



To sum it up, a modern dSLR allows considerable extra definition and detail over most P&S cameras, even at large sizes, and selective DOF is much more controllable in the larger imager sizes (crop 2x dSLRs and above.)

insanefred

Ciel_Rouge wrote: »

literally RAZOR sharp.

Unless you've been cutting yourself with old paper. I wouldn't use the word "literally" in that context.

NeilL

Yeah, along the lines of what Ziggy says, you can't directly compare tech. Photography is optics-physics-(electronics) based, and that base is immovable. Tech developments squeeze more and more out of that immovable base, but also involve push-pull compromises.

The old photos you talk about were very likely taken with a "sensor" (glass plate or film negative) at least 6 inches by 6 inches, and in strong outdoor light, and with everyone standing dead still for a comparatively long time, and with a very heavy camera on a very heavy tripod and tripped by a remote release. Then the image was hand processed to perfection. No problem, you can still do the same today. So no need to get nostalgic about the lost old days.

But when the market wants little pocketable cameras with sensors no bigger than your pinky nail, that people casually whip out and simply hold out in front of them in the general direction of their subject, in all and any conditions, and the image viewed at 72ppi on a badly calibrated display, well - there are no laws in all of creation that are gonna be on your side to give you the same result as above!

No basis then for your complaint, because a direct comparison is just not possible or sensible!

Neil

Ciel_Rouge

Sure, no point in comparing apples to oranges. BUT: this does not mean we should not want a similar performance LEVEL. You say the "sensor" used by the antique folks was 6 x 6". Why can't we have such sensors in dSLRs or even P&S? That would be expensive, sure. So why not have at least 3x3" or even 2x2"? Obviously the average Joe does not understand much more than putting the "thing" in front of him pointing in the "general direction" ;-) But when we go beyond snapshooting and venture into the world of actual photography, perhaps we as customers are too much "tamed down" since we are used to over-compromising in life in general I mean if we did not get so easily tamed with the "come on, it's only a digital camera, what would you expect" phrase, then maybe the manufacturers would actually start making the sensors bigger instead of putting more "35x" zoom values on their funny labels ;-)

On a side note - I've noticed that new P&S cameras are also getting expensive. And guess what, they are increasing the megapixel count by squishing more pixels onto the tiny sensors so now while your dSLR may be 10 Mpx, your "pocketable" P&S is 14 Mpx at the same time wasting the whole pixel count by a tiny sensor and crappy optics Also, some of the pocketables have optical zoom of 18x while the tiny sensor does not seem to make the whole thing worthwile But we are so used to "compromise" these days that perhaps for some manufacturers or in case of certain models it is no longer about "making cameras" but more about having a magic number to tell the mass consumer "it is a good camera, your neighbour has 30x and you can have 35x" and to sell the product in large quantity nevermind its real value for photography

Just a side note - purely theoretical.

NeilL

Ciel_Rouge wrote: »

Sure, no point in comparing apples to oranges. BUT: this does not mean we should not want a similar performance LEVEL. You say the "sensor" used by the antique folks was 6 x 6". Why can't we have such sensors in dSLRs or even P&S? That would be expensive, sure. So why not have at least 3x3" or even 2x2"? Obviously the average Joe does not understand much more than putting the "thing" in front of him pointing in the "general direction" ;-) But when we go beyond snapshooting and venture into the world of actual photography, perhaps we as customers are too much "tamed down" since we are used to over-compromising in life in general I mean if we did not get so easily tamed with the "come on, it's only a digital camera, what would you expect" phrase, then maybe the manufacturers would actually start making the sensors bigger instead of putting more "35x" zoom values on their funny labels ;-)

On a side note - I've noticed that new P&S cameras are also getting expensive. And guess what, they are increasing the megapixel count by squishing more pixels onto the tiny sensors so now while your dSLR may be 10 Mpx, your "pocketable" P&S is 14 Mpx at the same time wasting the whole pixel count by a tiny sensor and crappy optics Also, some of the pocketables have optical zoom of 18x while the tiny sensor does not seem to make the whole thing worthwile But we are so used to "compromise" these days that perhaps for some manufacturers or in case of certain models it is no longer about "making cameras" but more about having a magic number to tell the mass consumer "it is a good camera, your neighbour has 30x and you can have 35x" and to sell the product in large quantity nevermind its real value for photography

Just a side note - purely theoretical.

Sure.

But we are involving ourselves, when we buy stuff, in the marketplace, which has its own dynamics. The stuff that we buy would not exist for us to buy outside of the dynamics of the marketplace. You couldn't buy Nikon, Sony or Canon, etc, stuff unless those companies were making money. The way that they make money is selling stuff that people want, or what advertising has led them to believe they want. This is not theoretical at all. The reality is that no one thing exists in isolation, to be perfected as a thing in itself. Things exist, and develop, in a dynamic system - nature, technology, marketplace, and photographer!

Neil

M38A1

Much of your question centers around yield in a FAB environment for the manufacture of the sensors themselves. If you only have so much real estate on say, an 8" wafer, and you have to do a bazillion steps to that one wafer, then having smaller sensors (DX) provides for more sensors on the wafer. Conversely, with that same 8" wafer and the larger sensors (FX), the same bazillion steps have to occur, (ie: same fixed costs) but the quantity of sensors is considerably less. Thus the cost to manufacture is higher for the larger sensors on a per unit basis.

Now, take that to the next level of a 2" or 3" sensor and the price would be astronomical. Could some people afford it? Probably. But for the general population, taking into consideration production times, defects and thus yields, or general market demand, that's why we have what we have at this time.

Ciel_Rouge

Sure, the average Joes buy their "thing" en mass and probably support the production of real cameras But why are we so tamed in the higher shelf market? Why don't we simply demand larger sensors and I do not mean 2" if they are too expensive, but how about making the 35 mm equivalent some sort of a standard? I suppose the 35 mm equivalent is superior to the smaller one in every respect and this would also free us from having to convert focal length. If we suddenly stopped buying smaller sensor dSLRs perhaps that would lower the price and shift them into a more general market? Or take for instance my case - I could have bought the L120 and support the superzoom market but I shall probably buy a dSLR and support the dSLR market. It may not matter what I do, but if this was a more general process, a direction amplified in general communication, perhaps the manufacturers would start investing in sensor size instead of elevating the zoom factor indefinitely and squeezing ever more pixels into ever smaller and more "optically challenged" sensors?

NeilL

There's more stuff available right now that you can have if you want it than possibly you could take advantage of in the form of medium and large format. With digital, too, there is the matter of processing and post-processing software quality, an indispensable part of the workflow, like wet processing was, which of course you can still do. I really find it hard to grasp what you feel is lacking in the present situation. You have such an extravagance of options, surely?

Scott has given an actual example of compromise and the dynamics of the marketplace. 35mm slr is not just sensor size, it is a whole suite of technology, and a whole market niche. As I have said, you can't get far by isolating one item like sensor size. You can have mirrorless systems and pancake lenses with the same sensor size, but they will not give the same result as the traditional slr system.

Neil