Sensor size and megapixals? My understanding is that to determine how pic a picture you can print at high quality, you divide by 300, so a 24 megapixel full frame with 6000 pixel X...

wmurnahan Loc: Bloomington IN

My understanding is that to determine how pic a picture you can print at high quality, you divide by 300, so a 24 megapixel full frame with 6000 pixel X 4000 pixel could print out a 20 X 13 1/3 but using the megapixel to determine print size would mean that a 4/3 sensor that is half the size yet has 20 megapixels could print out almost as big a print at the same quality as a full frame.

Nikonian72 Loc: Chico CA

What reference do you have for this mathematics relationship?

Nikonian72 Loc: Chico CA

Individual pixel size is as important as pixel count. Read more here:
Understanding Camera Sensor Sizes and Resolution
http://www.throughdavidseye.com/2013/03/understanding-camera-sensor-sizes-and.html

lightcatcher Loc: Farmington, NM (4 corners)

PPI and DPI are not related. http://www.uglyhedgehog.com/t-286738-1.html

rehess Loc: South Bend, Indiana, USA

Nikonian72 wrote:

What reference do you have for this mathematics relationship?

Commonly, photographic material printed at 300 dpi is considered to be a "high quality" print.

GoofyNewfie Loc: Kansas City

rehess wrote:

Commonly, photographic material printed at 300 dpi is considered to be a "high quality" print.

I hope not!
Epson printers will print at much higher DPI that that-1440 or 2280.
Read about he difference between PPI and DPI in the previous post by lightcatcher or THIS ONE by CaptainC.

BebuLamar

GoofyNewfie wrote:

I hope not!
Epson printers will print at much higher DPI that that-1440 or 2280.
Read about he difference between PPI and DPI in the previous post by lightcatcher or THIS ONE by CaptainC.

Printers especially inkjet have very high DPI but to print in full color the PPI can barely get 300PPI. So for highest quality image you do not need to supply any more than 300 pixels per inch as few if any printer can take advantage of more than 300 PPI file.

BebuLamar

wmurnahan wrote:

My understanding is that to determine how pic a picture you can print at high quality, you divide by 300, so a 24 megapixel full frame with 6000 pixel X 4000 pixel could print out a 20 X 13 1/3 but using the megapixel to determine print size would mean that a 4/3 sensor that is half the size yet has 20 megapixels could print out almost as big a print at the same quality as a full frame.

Sure! Take a file from the Nikon D1 or D100 and compare it to the one comes from 20MP Panasonic GX8. This case the smaller sensor delivers better image.

GoofyNewfie Loc: Kansas City

BebuLamar wrote:

Printers especially inkjet have very high DPI but to print in full color the PPI can barely get 300PPI. So for highest quality image you do not need to supply any more than 300 pixels per inch as few if any printer can take advantage of more than 300 PPI file.

Good use of DPI & PPI terms!
I've read that 240ppi is usually sufficient.

rehess Loc: South Bend, Indiana, USA

GoofyNewfie wrote:

I hope not!
Epson printers will print at much higher DPI that that-1440 or 2280.
Read about he difference between PPI and DPI in the previous post by lightcatcher or THIS ONE by CaptainC.

Yes, I am aware of all that stuff. I was merely answering a question as to the source of a "mathematical formula".

Nikonian72 Loc: Chico CA

rehess wrote:

Commonly, photographic material printed at 300 dpi is considered to be a "high quality" print.

You did not answer the question "What reference do you have for this mathematics relationship?", which refers to the Original Post statement. 300 (DPI) has no direct relationship with sensor size, nor sensor density. A statement without documentation is merely opinion, no matter how many times it is repeated.

rehess Loc: South Bend, Indiana, USA

Nikonian72 wrote:

You did not answer the question "What reference do you have for this mathematics relationship?", which refers to the Original Post statement.

Yes, I was referring to the OP's dividing by 300. Which other calculation in that post is unclear to you?

Nikonian72 Loc: Chico CA

rehess wrote:

Yes, I was referring to the OP's dividing by 300. Which other calculation in that post is unclear to you?

Regurgitating a statement does not make it fact. The BASIS of the Original Post is unsubstantiated, and therefore unclear. DPI (printing measurement) has nothing to do with PPI (sensor measurement).
read more here:
FAQ: How is Dots Per Inch (DPI) related to Pixels Per Inch (PPI)?
http://www.uglyhedgehog.com/t-147932-1.html

Cdouthitt Loc: Traverse City, MI

wmurnahan wrote:

My understanding is that to determine how pic a picture you can print at high quality, you divide by 300, so a 24 megapixel full frame with 6000 pixel X 4000 pixel could print out a 20 X 13 1/3 but using the megapixel to determine print size would mean that a 4/3 sensor that is half the size yet has 20 megapixels could print out almost as big a print at the same quality as a full frame.

I have 30 x 40 prints from a 16mpx 4/3 sensor that look great...that's all the math I need...real life experience.

rehess Loc: South Bend, Indiana, USA

Nikonian72 wrote:

Regurgitating a statement does not make it fact. The BASIS of the Original Post is unsubstantiated, and therefore unclear. DPI (printing measurement) has nothing to do with PPI (sensor measurement).
read more here:
FAQ: How is Dots Per Inch (DPI) related to Pixels Per Inch (PPI)?
http://www.uglyhedgehog.com/t-147932-1.html

The OP regurgitated nothing. We already know that DPI is unrelated to PPI. The OP's question was about printing, which is why DPI matters, and why talking about PPI and its relationship to DPI is a waste of electrons. As others have already explained, 300 DPI is the norm for printing, so the OP's original arithmetic was 100% correct.