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02-24-2009, 01:40 AM   #76
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QuoteOriginally posted by RiceHigh Quote
This is not the first test which show such result, but I'm afraid that the bottle necks are the film scanners there, not the films.
Read more closely and you will note that the scans are downsampled to match the A900.


QuoteOriginally posted by RiceHigh Quote
Disprove what? I consider 300 dpi is standard, not too high and not too low as a printing resolution. If you consider otherwise, that's your *opinion*, what do you want I to prove or "disprove"?
The thing is that I work in the print industry and know that printing anything at more than 300 dpi is meaningless for nearly any application you can think of. The fact that you earlier said:
QuoteOriginally posted by RiceHigh:
Fuji Frontier photo printers could output far higher resolution than 150 dpi you've mentioned and higher than the standard 300 dpi and so does a domestic HP deskjet or Canon bubble jet printer. Most HP color laserjets can output 600 dpi, especially for A3 models, so?
...suggests that you don't really know what's going on in a printing process.

02-24-2009, 02:04 AM   #77
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QuoteOriginally posted by Erik Quote
Read more closely and you will note that the scans are downsampled to match the A900.
It has a large sampling/file size has nothing to do if the film scanners have grabbed all the picture data without resolution loss.

The key point here is the *workflow*. Analog workflow should be compared with digital workflow from the beginning to output. I have elaborated in my last reply, I won't repeat further.

QuoteQuote:
The thing is that I work in the print industry and know that printing anything at more than 300 dpi is meaningless for nearly any application you can think of. The fact that you earlier said:
So, HP or Canon who are the renowned printer manufacturers don't belong to the "print industry". I still remember that I had those professional A0 printers at my drawing office at work which could output 600 dpi, 10 years ago. Even an ancient HP plotter using colour plot pens specified up to 300 dpi in accuracy, so?

And, my $100 Samsung Thermal Printer must be the highest standard in the "print industry" as it really outputs true resolution at 300 dpi (the "highest" "industry standard")! I am really glad that I could get such an industrial standard printer at that bargain price!

QuoteQuote:
...suggests that you don't really know what's going on in a printing process.
Whether I know or not know something is not important. You should respond to the technical points (even not point by point) roughly if you really have found something wrong or have something concrete to say.
02-24-2009, 02:19 AM   #78
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QuoteOriginally posted by RiceHigh Quote
3120 LW/PH ????!! K20D's native output image pixels is 4672 x 3104.
Sorry, I had to remind myself about the vertical resolution and found it at this website. But your 3104 seems to be the correct figure.

QuoteOriginally posted by RiceHigh Quote
With Bayler's artifacts, it can by no means reach the theoretical 3104 limit, neither.
That's why I wrote "B&W test chart". If you directly evaluate the RAW image before demosaicing, this resolution is possible. Modern demosaicing algorithms can infer a lot of the colour resolution as well, but I agree that a colour image will in general not have such a resolution.



QuoteOriginally posted by RiceHigh Quote
Nor the *printing* resolution will change with different viewing distance.
That's right. No one said so. Different viewing distances call for different printing resolutions though.

Last edited by Class A; 02-24-2009 at 02:55 AM.
02-24-2009, 02:24 AM   #79
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QuoteOriginally posted by RiceHigh Quote
It has a large sampling/file size has nothing to do if the film scanners have grabbed all the picture data without resolution loss.
Actually yes, it does. You can see individual grains in those scans. There's just no more information there, it doesn't matter if you have an "analog workflow" or if you scan at nine trillion DPI.

QuoteOriginally posted by RiceHigh Quote
So, HP or Canon who are the renowned printer manufacturers don't belong to the "print industry". I still remember that I had those professional A0 printers at my drawing office at work which could output 600 dpi, 10 years ago. Even an ancient HP plotter using colour plot pens specified up to 300 dpi in accuracy, so?
The point was that you said "A HP Laserjet does 600 dpi so surely a 300 dpi image is less than optimal" apparently without realizing that the Laserjet rasterizes things HEAVILY and that it actually preserves detail somewhere closer to 100 dpi when printing photos. How many points of a single color (Cyan, Magenta, Yellow or Black) a laser or inkjet printer can output per inch is not relevant.

QuoteOriginally posted by RiceHigh Quote
And, my $100 Samsung Thermal Printer must be the highest standard in the "print industry" as it really outputs true resolution at 300 dpi (the "highest" "industry standard")! I am really glad that I could get such an industrial standard printer at that bargain price!
You should be, I'm sure it's a very good printer! I am not saying it is rocket science to build a printer that can output at a "true" 300 dpi. I'm just saying anything you're likely to see anywhere -- every magazine, every photographic print, every everything -- is a 300 dpi image, so your insinuation that it is "acceptable" quality at best is pretty laughable. That was the point.

As for your cheap printer and its relative merits, surely you realize that there is more to print quality than raw resolution..?

02-24-2009, 02:49 AM   #80
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QuoteOriginally posted by Mallee Boy Quote
He replied (with a wry smile) that it was shot with a Nikon D40, which I believe uses the same sensor as Pentax 6mpx dslr's (please correct me if I am wrong).
You are right. The sensors are the same (by Sony).

QuoteOriginally posted by RiceHigh Quote
So, with a 135 film of resolution 75 lp/mm, the lw/ph (line widths (dots) per picture height) is just 75 x 2 x 24mm, which is equal to 3600 lw/ph
24mm is the width of an APS-C sensor, not its height. You need to multiply by 16mm. The correct result is 2400 LW/PH.
QuoteOriginally posted by RiceHigh Quote
which is 1.5X more actual resolution than the 14.6MP K20D, which is only measured to be at 2400 lw/ph *at best*.
With the correct calculation your K20D resolution figure already matches the film resolution.
I doubt that the K20D resolution is just 2400 LW/PH. Please post a source (I cannot read the Chinese website you pointed us to).


QuoteOriginally posted by RiceHigh Quote
One pixel of our DSLR is of *one* colour only.
That is true for the RAW image. After demosaicing, all pixels contain all three colour components. You cannot simply divide the colour resolution by 2 (red and blue are represented in every second row/column in an interleaving fashion) because modern demosaicing algorithms regain a lot of resolution back by using resolution in other colour channels.


QuoteOriginally posted by RiceHigh Quote
Fact is a typical consumer grade ISO 100 slide film has much resolving power than any of the current 135 or smaller format DSLR sensor, so there is still a long road to run in the digital technology until it can match film for just the resolution is concerned.
According to many reputable sources this is not true. Many professionals chose digital over film and they are not driven by convenience.

QuoteOriginally posted by debbie Quote
so, are you saying that the K20D, for example, has a effective resolution of 14.6 Mp divided with 3??
In any event, it is not true. The maximum resolution loss you could claim for a Bayer array sensor is "divided by 2" (for each dimension). But because demosaicing algorithms are more clever then just binning colour components the real resolution is higher than that. You are right, you only get full 14.6 MP if you shoot a B&W scene and convert the RAW file 1:1 (without demosaicing). But the resolution loss for colour images is less than 1/2 or even 1/3 (per dimension).


QuoteOriginally posted by RiceHigh Quote
I always print my photos at 300 dpi (as it is the default factory setting). I also found that my 13 MP images printed on a 4R thermal photo paper always look sharper than the 6 MP ones, with more details and resolution.
If you always print at 300 dpi then your (uncropped) 13MP images will simply be larger than your 6 MP ones. They cannot look sharper because (by definition) both have 300 dpi. Perhaps you think you are printing at 300 dpi, but you are not?

Last edited by Class A; 02-24-2009 at 02:57 AM.
02-24-2009, 03:06 AM   #81
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QuoteOriginally posted by Marc Sabatella Quote
But this constant-noise theory does not always hold up in practice.
It does, when "everything else is kept equal" (which it isn't most of the time, but without this assumption you don't know what you are comparing against what).

QuoteOriginally posted by Marc Sabatella Quote
I think part of the reason is that the spaces *between* the pixel sites becomes more and significant as you increase the number of pixels.
The "everything else" being kept equal includes the ratio of sensitive to non-sensitve sensor area.

QuoteOriginally posted by Marc Sabatella Quote
Unless you find a way to shrink those gaps, you're not going to do yourself any favors by shrinking the pixel sites to fit more on.
True, but if that happens you are not only comparing pixel densities but also sensor sensitivity ratios.

QuoteOriginally posted by Marc Sabatella Quote
I suspect also that the extent to which noise increase with smaller pixel sites is not completely linear (or should that be quadratic?)
Noise increase due to pixel size reduction is a secondary effect. It is not as large as primary effects, e.g., sensor size. There is an optimal range of sizes for pixels regarding noise and modern high pixel density sensors are still within that range. Forum member falconeye knows all about it.
02-24-2009, 03:08 AM   #82
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I'm afraid the OP already left this topic somewhere at page 3 and maybe he already bought a canikon (as an earlier poster mentioned)... Anyways, just my 2 cents if he's still reading this topic.

I don't want to get involved in the 6 vs 10 MP fight. I also can't say anything about the K100D as I never tried that camera. But I have the K-m and also been using a 6 MP Nikon D70 for a few times, and I can say that you don't have to worry about "only 6 MP". It is enough for personal, hobby purposes. I've yet to see any significant, noticable difference between 5, 6 and 10 MP photos viewed on my monitor or printed in A5 size. Of course more MP is usefull if you want/have to crop, but MP count alone wouldn't worry me.
Read the features of the cameras, try them out in a local shop and decide according to which suits your needs the most, which fits your hand better (that is also very important!) and which is the one you can afford.
02-24-2009, 03:21 AM   #83
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02-24-2009, 05:01 AM   #84
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QuoteOriginally posted by RiceHigh Quote

The problem here is not about the printer. Its just about the digital image does not have enough data to fit /feed into the printer for making all dots printed to be meaningful.

But when other people suggested that 300 dpi is just too high a printing density, I disagreed, I think it is just somewhat a standard setting.
well, I think you have confused yourself with dpi and ppi. If the image consists of 300ppi worth of information, it does. And how the outcome of that printed image will be is up to your printer.
And 300ppi is usually enough information for the image not to display any visible pixels on the print.
02-24-2009, 05:01 AM   #85
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QuoteOriginally posted by julianactive Quote
Come on. What I posted was an observation of his blog. He has major problems with both Pentax and a Camera Web site. Why would anyone go through so much effort to trash others yet you rush to his defense?
His mind numbing blogs and posts have little to do with photography. Where are all his gallery posts? He is just a mud slinger and he tries to come off as this almighty diety on cameras.
Hang around for a while and see if he doesn't get on your nerves!
Certainly most of the people here are helpful and friendly but it seems like every forum has their haters on them that spend all their time pushing their agenda and Ricecakes is one of them.
Another Canon fanboy just got banned from this forum. Nothing constructive to say.
Sure there are going to be problems with cameras. That is why you buy them from a reputable place so you can send it back if it doesn't work or fit your need. I have no problems with people liking their other brands of cameras but to constantly come in here and trash Pentax is ridiculous.
Now if people want to talk about taking pictures and ISO and camera settings I am all ears.
I just don't dig MR. Rice cakes.
Now that will be that last word I have on him or about him.
1.) Rice High's blog is his blog and he is entitled to put whatever he wants on it.
2.) I've been using this forum for over a year and he hasn't gotten to me yet. You've been here for a week, have 20 posts, and already have a hate on?!?
3.) It's Rice High - not Ricecakes.

I'm not rushing to Rice High's defense (I'm not commenting on anyone else's posts). I am however, not very tolerant of name callers who's only purpose is to tarnish this respectful web forum.

c[_]
02-24-2009, 08:11 AM   #86
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QuoteOriginally posted by ll_coffee_lP Quote
1.) Rice High's blog is his blog and he is entitled to put whatever he wants on it.
2.) I've been using this forum for over a year and he hasn't gotten to me yet. You've been here for a week, have 20 posts, and already have a hate on?!?
3.) It's Rice High - not Ricecakes.

I'm not rushing to Rice High's defense (I'm not commenting on anyone else's posts). I am however, not very tolerant of name callers who's only purpose is to tarnish this respectful web forum.

c[_]

Then take the high road and lay off me.
02-24-2009, 01:05 PM   #87
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QuoteOriginally posted by RiceHigh Quote
A 6MP camera only gives 300 colour dots per inch for *all* dots to be counted. What you got with a Bayler sensor with 300 pixels are actually just *physically* 300 pixels, not 900 as you supposed (there has never been 300 x 3 physical pixels to give your 300 pixels of colours).
First, it's Bayer, not Bayler. Second, I know that the 2000x3000 pixels of a 6MP don't *start* as 2000x3000 RGB pixels. But once you've demosaiced them, that's what you've got.

Anyhow, artifacts or not, there is no getting around that there are three times as many R dots, three times as many G dots, and three times as many B dots in a 300dpi print than in your 100dpi monitor. Actually, if you get to multiple your monitor resolution by three to account for the fact that each pixel on the monitor is composed of three individually colored dots, then I get to multiply my monitor resolution by 6 to account for the fact that each pixel in the printer is composed of 6 individually colored drops. Unless you're thinking that this hypothetical 300dpi printer is really only printing 100 pixels, each comprising 3 dots of ink? If that were true, then we'd be comparing apples to apples. But that's not how printers work.

QuoteQuote:
However, your basic assumption was wrong from the beginning - One pixel of our DSLR is of *one* colour only. Getting the image with Bayler layout and re-use the pixels will not magically create 3 times more of *physical* pixels. As such, it could do no magic in getting more resolution.
I'm aware of how Bayer demosaicing works, yes - and I also know how to spell it. Doesn't change a thing, as if you insist on scaling the numbers that way, I'd just say that in that case, 2MP is actually enough for many purposes.

No matter how you choose to put numbers to it, it doesn't change the fact that *people* looking at *images* with their *eyes* (instead of crunching numbers whose significance they don't understand) generally agree that 6MP *is* often enough. Enough for everyone in every situation? - of course not. But enough for many in many situations. The fact that your numbers tell you it isn't enough for you won't change the fact that many people's *eyes* tell them it is enough for them.

QuoteQuote:
I will be glad to stand corrected for what's being wrong on my part. The maths, as shown above, are simple.
Indeed, but you managed to get a chunk of it wrong anyhow.
02-24-2009, 02:55 PM   #88
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QuoteOriginally posted by bx6768 Quote
How about K100D as my first Pentax DSLR?

DA 40mm should be a good choose, if I only want one prime lens right now?
That is an excellent choise. I would say the 35/2 could be a slightly wider and brighter lens. I think you should also consider the earlier models the *istDL and DS. I gave my DS to my sister when I bought the K20, but was playing with it a bit last weekend, and got seriously impressed with the picture quality produced by that 'old' camera. And the size is really small as well, fits well with the DA40 or FA35. And you should be able to find them at really good prices.
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