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### AuthorTopic: 21 vs 12 MP  (Read 13477 times)

#### dchew

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##### 21 vs 12 MP
« Reply #20 on: February 26, 2009, 07:26:57 pm »

I think it bothers you because in the context of a sensor resolution means pixels per square area.  Yet when it is described people only use the number of pixels; the sensor area is presumed to be constant in a comparison like this thread.

Dave Chew

Quote from: Gemmtech
As an architect and a math major I've always disliked this statement.  If I have a room and it's 10'x10' that's 100 sqft. if I double the square footage of the room it's 200 sq.ft. or 10'x20'.  Wouldn't the correct statement be, if you want to double both the horizontal and vertical resolution then it would be 48mp?  I agree that we have to stay within the confines of the sensor, but 24mp is double 12mp.  What if we changed the sensor size or aspect ratio?
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#### sperera

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##### 21 vs 12 MP
« Reply #21 on: February 27, 2009, 05:10:38 am »

Quote from: davewolfs
Realistically, in terms of details and image quality is there a big jump when going from a 12MP sensor to a 21MP sensor?  Any comments from those who have?

These are my personal findings from what I have seen and judged with my own eyes.....

......a 12mp camera such as my own D300's sweet spot print is about A4 at 300dpi

......tested out the D3x Nikon against the Nikon D300 and found linear enlargement at quality only around 30%.....so from 12mp to 24mp at the price it aint worth it...by at quality I mean around 300dpi

.....from a D300 to a 31mp camera linear enlargement at quality is 15cm to the sides extra, so about 45cm approx......

......to get double the linear enlargement at quality compared to a 12mp camera you're talking a 50mp camera.....

a 6x6 Hasselblad etc 120 roll at quality you're looking at around an A4 size before you start to curse the grain.....

a 5" x 4" at quality you're looking at around 635mm at quality

I'm currently shooting some fashion for a retail shop and producing 1m tall prints from a D300 which look great....so remember the viewing distance is a factor in all this.....
« Last Edit: February 27, 2009, 05:14:17 am by sperera »
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Stephen Perera
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#### springtide

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##### 21 vs 12 MP
« Reply #22 on: February 28, 2009, 05:56:45 am »

Quote from: Gemmtech
As an architect and a math major I've always disliked this statement.  If I have a room and it's 10'x10' that's 100 sqft. if I double the square footage of the room it's 200 sq.ft. or 10'x20'.  Wouldn't the correct statement be, if you want to double both the horizontal and vertical resolution then it would be 48mp?  I agree that we have to stay within the confines of the sensor, but 24mp is double 12mp.  What if we changed the sensor size or aspect ratio?

I couldn't agree more!

If you print at the same DPI, if you double the resolution then the print size would be doubled as long as we are happy that (talking metric paper sizes) A3 double the size of A4 (which I believe, since if I cut A3 paper in half I get two sheets of A4!)
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#### Rob C

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##### 21 vs 12 MP
« Reply #23 on: February 28, 2009, 10:09:44 am »

Quote from: sperera
a 6x6 Hasselblad etc 120 roll at quality you're looking at around an A4 size before you start to curse the grain.....

Interesting statement; have you tried it?

From experience, personal, using 35mm Kodachrome scanned, I´m doing A3+ and have no fears or doubts about granularity. On which film are you basing your surprising statement which I know can be clearly refuted by many pros? Maybe Tri X processed in paper developer?

If you´d like to have a look at even ONE pro who uses the Hass (and would probably break his sides with laughter were he to read your statement) take a peep at:

http://www.keithlaban.co.uk

And I assure you, A4 isn´t his limit...

Rob C

#### Roger Calixto

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##### 21 vs 12 MP
« Reply #24 on: February 28, 2009, 10:59:20 am »

Wow, his portah series is very impressive. Is he using velvia or something like that? His colors are *slap you in the face* beautiful.

I especially love:  http://www.keithlaban.co.uk/231_8.html

Is this something I can realistically shoot for (pun intended) with digital?

KT
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If my day job wasn't so cool, I'd quit and be a photographer =)

#### Rob C

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##### 21 vs 12 MP
« Reply #25 on: February 28, 2009, 11:32:35 am »

Quote from: kingtutt
Wow, his portah series is very impressive. Is he using velvia or something like that? His colors are *slap you in the face* beautiful.

I especially love:  http://www.keithlaban.co.uk/231_8.html

Is this something I can realistically shoot for (pun intended) with digital?

KT

I can´t reply for Keith Laban, but I suspect that the answer would be "yes" as long as you try doing it with MF digital. And you have the eye, plus the techniques in the various aspects of the job.

On the other hand, if you are interested in keepìng to a maximum of around A3+ then I would think that a top-line digital 35mm-style camera would keep you happy if the other parts of the equation were maintained. It would certainly put a smile on my face , if a painful hole in the wallet!

Rob C

#### neil snape

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##### 21 vs 12 MP
« Reply #26 on: March 02, 2009, 09:00:00 am »

For the first part:

I now have both the 5D and the 5D II.

Obviously the new camera has a higher pixel count so you can go up in print size without digital artifacts.

Yet I am going to keep both. Why?

The new file size is so big it can become unwieldily if shooting fashion.

I compared the new Hasselblad 39 II to the 5D II and find the actual image quality pretty close to the same, both having their own benefits.
I cannot yet say for sure if the image file size is the reason to justify the purchase or not. The Canon isn't all that good even with the new 14 bit processor in the shadows compared to other systems or drum scanned 6x6 film.
I did make some films though and the quality is remarkable. I like he dust shaker part, the new battery etc. So overall it's a good deal, but truthfully the image quality isn't all that much better than the 5d for fashion/beauty type of pix.

Second part> drum scanners can resolve clumps of grain, and certainly do produce noise off negative films. Drum scanners do not resolve the actual film grain. Yes indeed an A4 drum scan can be noisy looking if the neg has large grain clumps due to development. Yet with a pos film such as Provia at A4 on a decent drum scan you won't see any grain structure at all. I use to see some grain  after A3+ around A2 and definitely at A1 off Provia. Not a bad thing though , just the way film is like it or not.

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#### ErikKaffehr

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##### 21 vs 12 MP
« Reply #27 on: March 04, 2009, 12:50:07 pm »

Hi,

My experience is that scans from Provia using 3200 PPI on my Minolta DSMP scanner are definitively grainy. I made a 100x70 cm print from a 6x7 slide scanned on the DSMP. The print was astonishing and without any objectionable grain and very, very, very sharp at the plane of focus. I plan on some comparisons Sony Alpha 900 vs. 120 Velvia. The undeveloped but exposed film is already in the fridge...

Best regards
Erik

Quote from: KLaban
Hi Rob

You are right, except I'm not sure I'd break my sides with laughter. If sperera's statement 6x6 Hasselblad you're looking at around an A4 size before you start to curse the grain was true, I'd be more likely to burst into tears.

The fact is 80 Mpixel, 450MB (that's around 9000x9000 pixel) drum scans of Velvia/Provia/Astia 6x6 film will obviously resolve grain, I'd be disappointed if they didn't, but printed at 20"x20" there is still no evidence of grain. Sperera, this is what slow transparency film is all about. If you are seeing grain from MF Velvia at A4 then something is seriously wrong; perhaps you are seeing noise rather than grain resulting from a poor scan?

Keith
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Erik Kaffehr

#### Rob C

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##### 21 vs 12 MP
« Reply #28 on: March 04, 2009, 02:55:02 pm »

Quote from: ErikKaffehr
Hi,

My experience is that scans from Provia using 3200 PPI on my Minolta DSMP scanner are definitively grainy. I made a 100x70 cm print from a 6x7 slide scanned on the DSMP. The print was astonishing and without any objectionable grain and very, very, very sharp at the plane of focus. I plan on some comparisons Sony Alpha 900 vs. 120 Velvia. The undeveloped but exposed film is already in the fridge...

Best regards
Erik

I´m sorry, I´m not quite grasping what you mean: do you mean that the 100x70cm print was or was not grainy? In your first sentence you say the scans are grainy but in the next one you say there is NO objectionable grain...

Rob C

#### ErikKaffehr

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##### 21 vs 12 MP
« Reply #29 on: March 04, 2009, 08:07:21 pm »

Hi,

Sorry. The scans were just awfully grainy at actual pixels on screen. I spent about two hours in Photoshop on that file essentially working on sharpness and reducing grain. The image was still nowhere looking good at actual pixels. I sent it directly to the lab as a 200 MByte TIFF. It was printed at 200  lines per inch on a Lambda printer. The print was incredibly sharp and had no objectionable grain. Both the sharpness and the smoothness of the image was a great surprise to me as it was not really good on the screen.

The lab did no processing on the print, they have a service intended for professionals where they just print the image without interaction. They charge half price and very fast turnaround time. I cannot say that there was no grain in the print, I can say it was smooth and sharp. The reason that I don't say if there was grain in the picture is mostly dependent that I don't have access to it right now.

From this experience I would say I really don't expect any visible grain from scanned low speed slide film at A4 enlargement, as stated on this forum.

Best regards
Erik

Quote from: Rob C
I´m sorry, I´m not quite grasping what you mean: do you mean that the 100x70cm print was or was not grainy? In your first sentence you say the scans are grainy but in the next one you say there is NO objectionable grain...

Rob C
« Last Edit: March 04, 2009, 11:16:00 pm by ErikKaffehr »
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Erik Kaffehr

#### polizonte

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##### 21 vs 12 MP
« Reply #30 on: March 11, 2009, 12:55:40 pm »

[quote name='kingtutt' date='Feb 23 2009, 03:53 AM' post='262220']Anyone else in that boat? I have a 30d and was pretty gung ho about upgrading to a 50D this year when the price goes down but after all I've been hearing about super-sensibility to camera shake and on-the-spot focusing, I think I'm going to end up going to a used 40D - Why not buy a new one at the current bargain price? Maybe a kit, sell the 28-135 - I also shoot Nikon also but my 40D/ EF 200mm f2.8 L is my fun combo.

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