Pixel Count/Sensor Size

[Bill Pierce]

The tug of war between high pixel count and pixel size/sensor size as they effect image quality has probably resulted in more misleading articles on the web than any other facet of digital photography I can think of. For the most part this is simply because folks want specific answers, specific numbers that apply to everybody. In terms of what you take pictures of, the sensor size of your camera and the print sizes that are important to you - how many megapixels work for you? I’ll tell you what works for me when we get a few other answers simply because my professional and personal work produce slightly different answers.

 

[goamules]

12Meg to 16Meg seems plenty for me.

 

[daveleo]

I have no profesional needs.
I print 8X10", a few rare 12X18", using APS sensors. 12-16MP work just fine for me too.

 

[helen.HH]

I'm mostly still Film but later in this coming year 2015 I will seriously delve into the modern world of digi if I can just just settle on a camera. 🙄

In the past , I was content with a 5 megapixel output w/ the 0ly E1 & the 50 R summicron / 8.5 x 11 prints looked Grand ...still do

This past year I played with the X2 & M- E ,
so a 16 megapixel is just Fine, Good enough for me / 9x 12 prints Look lovely
(Have not tried anything bigger print or megapixel, but don't 'feel' the need)

 

[Timmyjoe]

12-16 megapixels works well for photojournalism work, as anything bigger just slows you down for meeting deadline.

For gallery stuff, I still shoot Tri-X and scan it with a Coolscan 9000. Not sure how many pixels that is, but it makes really nice 16"x20" prints.

I'm sure there are needs for cameras with higher megapixel counts, they're just not my needs.

Best,
-Tim

 

[Roger Hicks]

12Meg to 16Meg seems plenty for me.

Dear Garrett,

Same here, at least up to full page A4 and not bad at double page spread (A3). Much over about 20 Mp is into medium format territory -- though that can be nice/useful too.

Cheers,

R.

 

[splitimageview]

It's great to have 20-24 when shooting sports, for cropping when the tele is not tele enough. Otherwise, half of that.

 

[thereabouts]

My personal MP/resolution requirements are based on what my printers need me to supply for optimum results.

I wear two hats (at least). Firstly professional print design, where photographic images might be printed using offset litho printing. This requires that images be around twice* the resolution of the halftone screen, at the printed size.

So for my use (your milage may vary), the following applies.

For a newspaper, (printed on newsprint) which often only uses around a 65 lines per inch screen (for example) the supplied artwork may be as low as 130 dots per inch. So that's about 1.7 megapixels at A4 size.

However, if I am using an image for a full colour glossy brochure, which can use a 225 line screen. Perhaps even 300. The image needs to be that much higher resolution. For a 225 line screen, I would need to provide an image at around 450dpi (around 20 megapixels). If it was a high-end publication, I would probably provide it at an even higher spec. For an A3 double page spread, that could rise to around 80mp, in theory. Which is where medium format comes in for fashion shoots.

When I supply images for exhibitions, the supplier that I use for high-end inkjet output wants images at 360dpi. So, for an A4 print, that's about 12.5 megapix. For A3, it's closer to 50mp. In practice, because gallery images are generally viewed from a bit of a distance, I've found it perfectly safe to use 270dpi (around 28mp at A3) in the past.

Of course, it's often possible to get away with much less than the above. I don't do fashion shoots, but I wonder how many fashion phtographers have access to 80MP cameras?

But, for me, one of the reasons that I chose a Sony Nex 7 and then an A7, is because of the 24mp sensors. It gets me as close as I realistically need to the amount of data that I generally need in my photography. An A7r would cover even more bases, but as I only hand-hold when shooting, I thought that the A7 would give me a more reliable result. (From what I've read, an A7r – like the Nikon d800e – would come into its own more with tri-pod use).


A couple of useful links:

http://web.forret.com/tools/megapixel.asp

http://www.designtalkboard.com/tips/dtp/dpi.php


* Actually the traditional recommendation is generally 1.5 to 2.5 times the halftone line screen. Below that, the image has the potential to appear pixelated. Above that, there is no noticable increase in quality and at very high resolutions, might even begin to look less sharp.

 

[Bill Pierce]

I said at the beginning of this thread that I would talk about the gear that I use once other folks had spoken up.

A modest amount of my professional work is studio portraiture. The fact that a low pixel count camera might not resolve fine wrinkles and enlarged pores missed by the retouching process hardly seems a worry even if the picture is of a character actor and going to poster size. In other professional work which appears on the web or in print, the images are relatively small and certainly do not need a lot of megapixels. Truth is, a lot of my gear has more megapixels than I need; the gear was chosen for other reasons.

My family, my friends, personal snapshots see a lot of their life as email jpegs and small framed prints. Not the need for a lot of megapixels there…

Some personal work and some of the work I did as a photojournalist does end up on gallery walls or in museums. The paper size that I currently favor for that work is 17x22 with the smallest border usually being around an inch. Currently much of the personal work consists of “street photography,” annoying perfectly innocent people with my little camera. For that I currently use relatively small cameras with 16 MG APS-C sensors. Do the math and you will see that I’m not going to make those 17x22 in prints at 360 dpi without some upsizing. Without upsizing they come in at about 245 dpi. I’m fine with that. Perhaps if I were an architectural, landscape or still life photographer that would not be adequate. Perhaps if I sat with my nose against larger prints that would not be adequate. But compared to my 35mm film work scanned on an Imacon scanner at 6300 dpi, my digital work is “sharper.” (I know “sharper” is not an official technical term.) My studio work is “sharper” not because the cameras have more megapixels, but because the camera are very accurately focused, the lenses are at their optimum apertures and a high speed strobe or a tripod eliminate the camera movement. Someday I’ll up my megapixels, but it’s not high on the priority list.

 

[GaryLH]

12-16mp is actually good enough for me given on average I only print 8x10 w/ occasional 13x19. Anything larger like 16mp, is mainly so I can crop up to about 2x during post processing. The only reason I would ever go to 36mp or higher is so I could use a 24f2.8 prime and crop to about 75 fov and still have a good 11x14 print (max).

Gary

 

[DCB]

I have a nice 16x20 from a 6MP that looks great...my daughter won 1st place in a state school competition.

More may be better...it dependes what you need to do with it.

Peace

 

[thereabouts]

The fact that a low pixel count camera might not resolve fine wrinkles and enlarged pores missed by the retouching process hardly seems a worry even if the picture is of a character actor and going to poster size...

I think that it's less an issue of 'not resolving' detail (resolution in this instance is not about the ability of a lens to 'resolve' information, for example).

The detail is probably there for any decent modern camera sensor and lens. The issue is a question of the printed image showing all of the image at its optimum. If an image is printed at a lower than recommended resolution (for the device doing the printing), then the whole image is equally affected. Sure, some areas may be more obviously affected than others for different types of photo. But it's not necessarily about details such as pores and wrinkles.

This may be semantics, but only up to a point. An image printed at too low a resolution can look soft, and sometimes even pixelated, throughout.

For me, it seems a shame to spend thousands of dollars on lenses and then negatively affect the final output, with a low resolution print. An image can suffer much more at the print stage, than it ever will due to choice of film, camera brand, or lens.

 

[thereabouts]

Just a general note (and I am not referring to anything said on this thread).

The whole megapixel debate can be overblown, especially amongst the gear focussed dSLR crowd. But I've also noticed a kind of inverted 'backlash' against this from other quarters. Sometimes this is healthy. But, at other times, it strikes me as a kind of 'anti-science'.

Like photography, printing is part art and part science. The point of using the best image resolution, for the targetted printing device, is so that the art can be represented in the best possible way.

 

[John E Earley]

Most manufacturers would like us to think that pixel count is all that matters. It's much easier to market "24 vs 12" than to explain the issues of the physical size of the photo elements (pixels), the area of the image sensor, the design and quality of the filters and microlenses bonded to the image sensor and possibly most importantly as sensors advance, the firmware that processes the recorded data.

This also leaves out the resolution match of the lens and the sensor but that is another topic.

 

[DCB]

If I think I want to go with big prints, I'll shoot my 6x7 and have it scanned.

Peace

 

[Rob-F]

I used to have a Leica Digilux 2. It was only 5 megapixels. I printed 7.5 x 10" at 256dpi, and had no complaints. Today all my cameras are in the 10 to 12MP range. I think the largest I can print at home is 11 x 17, and I think I'm getting all the quality there is to be had with 10 or 12MP.

 

[Spanik]

If I'm going to put it through the web or a illustration in a document then 6Mp is plenty even allowing for some cropping. And I still use an old camera for that. For the rest I could live with something around 16Mp. I do have some shots where 16Mp isn't cutting it because of having too much to crop, mostly because a more appropriate lens wasn't at hand. But I haven't seen anything to replace a G617 yet without an awfull lot of setup and stitching.

 

[darya151]

I don't really understand the relationship between the 'physical size of pixels, the area of the image sensor, the design and quality of the filters and microlenses bonded to the image sensor and possibly most importantly as sensors advance, the firmware that processes the recorded data,' as John mentions in his above post. I wish I understood this! I have seen amazing images from 5 or 6 pixel cameras, coupled with great lenses that have a more contoured three dimensional look than cameras with far more pixels. To me, this is what makes it difficult to assess what you really need out of a digital camera. I have a digital camera with very fast focus, which has meant I've been able to capture a moment, but there's a lot more to it than that - what you see, how you see it... The answer to this partially lies in the type of camera you use, but the other part is in the 'art' of seeing -or the act of anticipation. Not understanding the science has lead me to look for something simpler to use. Please shed some light on this!

 

[Bike Tourist]

The 24mp of my D610 seems like overkill. My Df has 16mp and allows me to never worry about ISO. 16mp seems quite adequate for any of my purposes — personal and microstock. I seldom print anymore.