Large Magnificent Images on OPF: What Resolution?

[Stan Jirman]

Well, considering you are one of the few guys who's work i return to, that gives me pause. Maybe when we started "Rules" were made that seemed necessary at the time. However, the intention has been to be an open forum. Even the "rules" are open for challenge. I have no recollection of where we differed but, let's revisit that subject.

Well, specifically, I had issues with two rules: one picture per post, and 600 or whatever as the longer edge. Rarely do I post on FM just one picture in a thread; often, I consider them part of a group. Other times, I have multiple pictures of the same subject and quite honestly don't know which one "works" and I ask the public for help. Hard to do with one picture.

The size of the images is another matter. On FM, I post 800 along the longer edge. That's 30% more length, or 70% more pixels than here. My standard print size is 24x36", so seeing an image 600 wide is pretty sad.

There was something else, but I forgot

When you, yourself post critique, Stan, I value it especially as it comes from someone with experience, talent and maturity.

My talent is mainly luck; luck to be able to go places that most people can't. Luck to have a wife who supports this obsession and spending habit. And don't even get her started on maturity

 

[Asher Kelman]

Well, specifically, I had issues with two rules: one picture per post,

Well that depends what you mean to achieve by the post!

Now to study a work of art, the more real estate one can devote to one picture*, the more the discussion can be focused.

The push towards less images posted for serious critique is that it allows clarity and less generality. However, no one rule, but common sense is possible here.

If one is describing an event, such as a parade or a riot or a tragedy, 30 pictures might be in order as each one will tell another essential part of the important story.

However, 30 pictures of the same beautiful model can be sometimes boring unless there's a story to tell!

So there must be some evolution of the forum that escaped you or I, since I thought that what I described is what we were doing from the beginning!

Now as far as width is concerned, in general we have 400 pixels wide for the frront page gallleries, 60 pixel for most other images, 800 pixels wide for a Challenge, for example The Central Park N.Y. and the Ships at Sunset challenge3s called for 800 pixels wide.

Now if one has an image that really must be wide, say a panorama, then go 1200 pixels wide. Let me know if that is still a problem.

Do we need an ability to open a larger image in another window?

OPF will always retune to the needs of making and sharing images. So if we can do it better, let us know.

Asher

*If it's for critique and the picture belongs to a set to be viewed together, then it's up to 4 images per post. The fewer the better. Who knows, maybe there's 7 in the set, then post the odd three in an immediately following post.

 

[Erik DeBill]

The size of the images is another matter. On FM, I post 800 along the longer edge. That's 30% more length, or 70% more pixels than here. My standard print size is 24x36", so seeing an image 600 wide is pretty sad.

I think this is a general problem with web display. The size of a "print" is limited by the size of people's monitors. You can play cute games (looong images that must be scrolled through, for instance) but you can't really show something truly large.

I've got one I'm probably going to post soonish that shows this up nicely. It has really hammered home the difference between small and large prints, and how some images NEED the larger space to have impact. Unfortunately, few people have desktops > 1000-1200 pixels high, so I'm not sure if there's any way to get the right feeling on a computer screen. Even using a projector won't help in some cases, since you're just making the individual pixels larger.

Whatever size we choose, some images aren't going to work as well and want to be bigger (or smaller?). I'll probably post the image I mention above, with a request for feedback. I'll link a larger version and try to explain my thinking about it needing the additional size, so I hopefully get feedback on the intended image, not the thumbnail.

 

[Asher Kelman]

Erik,

Why don't you post the image at 600, 800, 1000 and 1200 pixels and lets see what people's experience is.

That's four images.

I'd like to see what people appreciate.

Asher

 

[Bart_van_der_Wolf]

I think this is a general problem with web display. The size of a "print" is limited by the size of people's monitors. You can play cute games (looong images that must be scrolled through, for instance) but you can't really show something truly large.

I've got one I'm probably going to post soonish that shows this up nicely. It has really hammered home the difference between small and large prints, and how some images NEED the larger space to have impact.

IMHO the issue has more to do with viewing angle and distance.

If one views a large image, say a poster on a wall, it is usually viewed from a lower viewpoint, which enforces a feeling of image height. When I view architectural images with proper keystoning correction from above (say in a small print held vertically below my eye-level), I get the feeling that keystoning was over-corrected. The same print laying on a table viewed from 'below' the image's horizon looks more natural.

Similar effect with viewing distance. If we view from a distance that is not proportional to the focal length used for the image, our sense of perspective is disturbed (which can be deliberately used to invoke emotion).

If an image is viewed from the relative/imaginary position of the entry pupil of the lens, perspective is perceived completely natural regardless of the image size. Just magnify the lens' focal lenght by the image magnification factor for natural perspective viewing distance/angle.

Bart

 

[Asher Kelman]

IMHO the issue has more to do with viewing angle and distance.

Similar effect with viewing distance. If we view from a distance that is not proportional to the focal length used for the image, our sense of perspective is disturbed (which can be deliberately used to invoke emotion).

Bart

Hi Bart. That's fascinating and seems correct. Can you come up with any guidelines and/or examples of how this can work?

Asher

 

[Bart_van_der_Wolf]

Hi Bart. That's fascinating and seems correct. Can you come up with any guidelines and/or examples of how this can work?

To answer a question with a question.
Q: Why does a wide angle shot look like a wide angle shot?
A: Because we are looking at it from the 'wrong' (normal) viewing distance!

But if you view a wide angle shot from a proportionally shorter distance (say a 24mm shot from ~half the viewing distance of a 50mm one), we see the same FoV and perspective (converging lines and relative subject distance magnification) as the lens did, so perspective looks more normal.

It kind of resembles looking through a wire frame for composition. Our feet determine scene perspective, the wire frame distance determines FoV, our relative viewing distance of the result determines/stresses the 'effect'.

If we look at an image from 'too far' away, the effect will be like a wide angle shot, with (subconscious) emphasis on the foreground features. If we look at an image from 'too close', we'll get a 'compressed perspective' like many telephoto shots.

This is often a combined effect because we can deliberately choose a closer perspective point for shooting with a wide angle, thus giving the foreground even more weight (knowing that the viewer won't, or won't be able to, view it from a shorter distance).

As an aside, that's why I encourage (particularly starters) to use fixed focal lengths. They 'force' to make a decision about perspective, before the shot.
It is also why I like shooting stitched panoramas with 'normal' focal lengths. Looking at them from a normal distance will give a natural/normal perspective, only with a wider FoV. And blowing them up will definitely give an an impressive 'telescopic' effect, matching the additional detail compared to normal visual acuity.

After all, we're playing mind games by exploiting these emotional reactions (exaggerated versus compressed perspective, relative to expectation) to non-natural viewing perspective.

Bart

 

[Sean DeMerchant]

Unfortunately, few people have desktops > 1000-1200 pixels high, so I'm not sure if there's any way to get the right feeling on a computer screen. Even using a projector won't help in some cases, since you're just making the individual pixels larger.

Well, roughly 45% of users of this site have screen resolutions at least 1000 pixels high according to the stats.

I personally tend to post huge images for the web (900x600 + border) and since I pay for their bandwidth I choose to personally ignore those with smaller displays as tiny images do not look as good to my eyes. Primarily this is because at 400x600 one cannot even tell if an image is in focus. There is just too little image to judge and that's not very helpful.

There is also a large block of users ~25% that run at 1024x768 and I highly encourage them to run at least 1280x1024 if they want 80% or more of the sites on the net to work. Tiny resolutions are going out of style in practice and such tiny resolutions destroy productivity on a computer. I run at 1600x1200x2 and the x2 (second display) increases my productivity by 30-40%.

enjoy your day,

Sean

 

[Cem_Usakligil]

...If an image is viewed from the relative/imaginary position of the entry pupil of the lens, perspective is perceived completely natural regardless of the image size. Just magnify the lens' focal lenght by the image magnification factor for natural perspective viewing distance/angle.

Hi Bart,

Very informative post, thanks a lot. Let's see if I understand the formula correctly:

Given:
Sensor size of the camera: 20 mm
Focal lenght of the lens: 50 mm
Print size: 400 mm

Calculated:
Magnification factor: 20 x (is this what you've meant by the magnification factor?)
Natural perspective viewing distance: 50 mm (focal lenght) x 20 = 1000 mm (i.e. 1 mt)

Now I know why we sometimes instinctively feel the need to enlarge a particular image .

Cheers,

 

[Bart_van_der_Wolf]

Hi Bart,

Very informative post, thanks a lot. Let's see if I understand the formula correctly:

Given:
Sensor size of the camera: 20 mm
Focal lenght of the lens: 50 mm
Print size: 400 mm

Calculated:
Magnification factor: 20 x (is this what you've meant by the magnification factor?)

Yes, you've got it. 20mm becomes 400mm, therefore magnification factor was 20x. In order to keep the same projection distance ratio, the viewing distance becomes 1 metre, if we want to maintain that 'natural' perspective sensation.

Natural perspective viewing distance: 50 mm (focal lenght) x 20 = 1000 mm (i.e. 1 mt)

Now I know why we sometimes instinctively feel the need to enlarge a particular image .

Indeed, any excuse will do.

Bart

 

[Erik DeBill]

Well, roughly 45% of users of this site have screen resolutions at least 1000 pixels high according to the stats.

With the new trend towards wide screen format monitors, it's now quite expensive to get taller than 1050 pixels..

My 20" monitor won't go past 1680x1050, and that seems to be fairly standard right now. Even going to the more expensive 23 and 24 inch LCDs only gets you 1920x1200. That's fine for landscape formats, but portrait images really just can't be very tall and still fit on screen.

I spend most of my work day on a (<1 year old, expensive) laptop that does 1280x800. That isn't a market that anyone should be optimizing for, but it does underscore that brand new computers are coming out that physically can't display what old cheap computers from 5 years ago were capable of.

The shift from 4:3 to widescreen has been a big loss for anyone interested in a vertical format. Hopefully we'll start seeing more applications designed to take care of this lopsided format, but the OS and style guides will no doubt keep eating the top and bottom of our screens for some time to come.

The change from CRT to LCD has also been a big loss. LCDs don't have the same resolution as CRTs, so you can't fit the same amount of data on screen. So far I've been waiting 3 or 4 years for an LCD that would match my old 19" monitor at 1600x1200 without costing an arm and a leg. I'm about to give in and order a 24" LCD from Dell just so I can get my vertical space back. It'll cost 50-100% more than that CRT. It'll look a little sharper, use less power and take less space, but that's a lot of money for marginally more pixels.

I personally tend to post huge images for the web (900x600 + border) and since I pay for their bandwidth I choose to personally ignore those with smaller displays as tiny images do not look as good to my eyes. Primarily this is because at 400x600 one cannot even tell if an image is in focus. There is just too little image to judge and that's not very helpful.

This is your right. Personally, if I routinely have to scroll to see entire images after the page first comes up, and have to scroll to find navigation elements, I don't stick around to look at a gallery. I can't get the same impact I would if the images were loading entirely on screen, and the scrolling is jarring. That's one reason I don't browse web galleries much on this laptop. The screen is 800 pixels tall. I lose about 200 to Windows XP and Firefox (I measured), so you really can't post anything > 400-500 pixels tall without making me start scrolling.

I'm well aware of the need to make tradeoffs in web design. I'm sure there are still people out there at 640x480. Thank god I'm not one of them. At work, I've had people ask me to make the site I maintain work on cell phones and PDAs (I told them "no"). It all comes down to target audience and intended usage. We might be able to do images 1000 pixels tall in photo discussion forums, and the overall site design is probably safe at that height, too. I'd never go that big for images in a web gallery, and if I was planning for my site to get used by laptops (say a business oriented website) I'd insist on it looking good with no more than 600 pixels of vertical display.

 

[Asher Kelman]

Erik,

So I'm not the only one mad at not being able to see enough of the vertical images.

The so called 17 inch screen of the MacBook Pro is not as tall as previous 15" LCD screens on the 15" monitor Apple sold.

So, with all this, back to the original question, what is the max dimension for a large detail rich image you could benefit from online?

I ask this in order to know how we might in future deal with Panos and other large images.

Asher

 

[Cem_Usakligil]

In line with Eric's and Asher's posts, I too am missing the vertical pixels in modern LCD monitors. One has to pay top prices for 24"+ monitors that only support up to 1200 pixels vertically.
I have a setup of dual 1680x1050 monitors (20"). Out of curiosity, I'll pivot them both to the vertical stand, which will then give me 2x1050x1680 (i.e. a desktop of 2100x1680 pixels). I hope to discover whether it is a better resolution for my workflow, although it will definitely look awkward at first. Will let you know when I come to some conclusions .

Cheers,

 

[Bart_van_der_Wolf]

... what is the max dimension for a large detail rich image you could benefit from online?

That may be hard to answer in any way other than; bigger is better. Perhaps 1024x768 pixels (give or take the space a browser claims for its controls) is a practical browsing/storage upper limit?

I ask this in order to know how we might in future deal with Panos and other large images.

Approaches like "Zoomify" or Java applets (some of which also allow HDR variations of JPEG!) seem the only possibility to exceed the image resolution limitations of displays. Obviously, such approaches cannot offer the 'immersive' effect, especially when zooming out to view the whole composition, because they only offer a viewport to part of the full image or a reduced size/resolution total view.

Bart

 

[nicolas claris]

I agree with all that we always have a problem to show portrait (as opposed to landscape) pics on the web.
I would like to point out that we do also have to care about server space but also as time needed to load large pics. Yes I know the stats of OPF site and the huge amount of connected members thru DSL, this is not a reason to penalize others, imagine a page to load with 25 posts including 10 pics each with 1024 pix or more...

We have to understand and accept that all media are not equal but complementary, large format prints, brochures, books, slide shows and web have all their strengthes and weaknesses.

This is the reason why, some months ago I declined the invitation here (made by one of the photogs I like the best) to have Large Format Exhibition within OPF.

Large format is to be seen... large.

And let's increase the size of pics posted once monitor gets bigger...

In the meantime, Bart' posts let us know and learn much more informative facts, thanks Bart for that.

 

[John_Nevill]

I'd agree 1024 or even 800 is a perfectly good size, although as Bart suggests there will soon be zoomify for the discerning pixel peeper of larger images.

 

[nicolas claris]

Large format on "small" screen?
Check-out these G6 snapshots (done in Dusseldorf Boot Messe last week) at 900 pix, picture enlarged is mine... and amazingly sharp...

That sailing yacht is 117' / 35,66 meters long (in real)

 

[John_Nevill]

Nicolas, Great shot,

I'm curious to know how many printed segments make up the display?

 

[nicolas claris]

Thanks John
I forgot to look at ! (I didn't do the print) but I guess, 2 segments. The image is roughly 4 x 6 meters (12 x 18 feet)...

 

[Nill Toulme]

C'est vous in the pic, Nicolas, sans hair? ;-)

Here are the screen res stats for visitors to my website:

1600 x 1280 2.49 %
1280 x 1024 30.06 %
1152 x 864 3.18 %
1024 x 768 46.46 %
800 x 600 8.67 %
640 x 480 0.10 %
Other Resolution 9.05 %

This is probably a pretty good cross-section of average computer users, not photography enthusiasts or tech mavens. It's starting to look like we can pretty well toss out the 800x600-and-below crowd, but I still limit my images to 700x500 for bandwidth and "theft" purposes. I'm generally too lazy to make a separate version for posting here; what you guys see is what the customers see.

Erik I think you might be pleasantly surprised when you start working on a good LCD. I replaced my beloved 21" Trinitron CRT early last year with a 1600x1200 20" NEC 2090uxi and couldn't be happier (although I am looking covetously and lustfully at the new widescreen 2690wuxi).

Nill
~~
www.toulme.net

 

[Asher Kelman]

88% of people here have screens 1024 or greater!

Thats pretty good. 64% are 1280 or better.

Asher

 

[nicolas claris]

C'est vous in the pic, Nicolas, sans hair? ;-)

Nope! he is the client (the builder of the yacht)

I'm here You'll see than I'm not (yet) chauve (sans cheveux), well to be honest....

 

[Erik DeBill]

Erik I think you might be pleasantly surprised when you start working on a good LCD. I replaced my beloved 21" Trinitron CRT early last year with a 1600x1200 20" NEC 2090uxi and couldn't be happier (although I am looking covetously and lustfully at the new widescreen 2690wuxi).

I work on 3 different monitors. The tiny laptop screen, a 19" CRT at work, and a 20" LCD at home. The 20" LCD replaced a 20" CRT. Previously I ran the 20" CRT in a dual monitor configuration with a 17" LCD that only had analog inputs. Switching to the nicer 20" LCD with DVI inputs I was very impressed with just how sharp the image was. All the same, I miss the extra 200 rows of pixels and I worry about brightness changing when it's viewed at different angles.

 

[Erik DeBill]

Erik,

Why don't you post the image at 600, 800, 1000 and 1200 pixels and lets see what people's experience is.

That's four images.

I'd like to see what people appreciate.

Asher

Here you go. I'm not done processing it yet - I've been rather sidetracked with other things the last few days, but this is the work in progress, downsampled (bicubic sharper) to those four sized.


600x301

800x402 (largest that will fit on my 20" LCD)

1000x503

1200x603

 

[Asher Kelman]

Eric,

as much as I don't want to admit it, I must say that the images dont really come alive until the 1200 dpi one. This might be how you have processed them as the last one seems very sharp and contrasty and seems to be much more dimensional.

The last magnification shows very well on my PowerbookPro.

Much of the upper 2/3 pictures has no detail and no matter how large it would be, little would change except how one shows tonality.

I'd like to hear other opinions.

Problem is that if we have too large size of images, we will choke the website and slow down.

I guess we should use 400-600 pixels as in the front page galleries which show very well.

The larger images can be allowed if the image requires it but we need discipline.

We want images to look superb but not waste server overhead.

Now how do others feel. What is the smallest if the images you would be satisfied with/

Thanks for the demo,

Asher

 

[Ray West]

Hi Eric & Asher,

On my 1600/1200 monitor, maybe 18% of the vertical space is occupied with toolbar/browser frame, etc. I do not want to turn that off to view images on web sites. The 1000 high image will almost fit on. The bicubic downsizing is not 'the best there is', but the 'best' depends on the size of image, type of image, amount of reduction, final destination, etc.

I think one solution to this and other problems, would be for opf to host a small thumbnail, in line with the text, which then, on clicking, linked to the owner's larger image. Then, if the image owner loses the link, for whatever reason, at least the rest of the thread makes sense, if not in the glory of the most desirable size.

At the moment, if for example you go to any of the challenges, in particular the central park M8 photos, it can take a while to scroll down to a particular image, as you wait for large images to load, from various servers around the net.

But, it depends how you want to use opf.

There was an 'old standard' of 800 by 600. This may still be best for folk with laptops, (and dial-up)..., and I think it is still good enough for the rest of us - link to something bigger, if required.

Best wishes,

Ray

 

[Ray West]

sort of like...

here's one I tried to prepare earlier-

But you'll have to click the link below, to get the effect of thumb to image.

http://www.yertiz.com/images/test.htm


I can't get the code into this post, but the idea is to get the thumb hosted on opf, and then links to the larger image stored elsewhere.

so all you'd get in line was the thumbnail image.

I reckon a bot could be written, to automatically do this. I'm away for a couple of weeks, else I'd do it ... believe that, you'd believe anything - but it should be possible, if deemed worthwhile.

Maybe too much browser back button required, maybe worth a try.

Best wishes,

Ray

 

[Erik DeBill]

On my 1600/1200 monitor, maybe 18% of the vertical space is occupied with toolbar/browser frame, etc. I do not want to turn that off to view images on web sites. The 1000 high image will almost fit on. The bicubic downsizing is not 'the best there is', but the 'best' depends on the size of image, type of image, amount of reduction, final destination, etc.

I think one solution to this and other problems, would be for opf to host a small thumbnail, in line with the text, which then, on clicking, linked to the owner's larger image. Then, if the image owner loses the link, for whatever reason, at least the rest of the thread makes sense, if not in the glory of the most desirable size.

I think this is probably the best shot. If even a 1200 pixel tall monitor can't hold a 1000 pixel tall image, then we really should consider asking people to keep them to 800 or 900 tall (800 should fit on a 1024 tall monitor, which catches the old 1280x1024 standard as well as the newer 1650x1080). Then adding a link to a larger image where warranted allows for pixel peeping and people with large screens seeing it as large as it can be.

Also, who says we have to have the same limits for horizontal and vertical? "Don't make your image larger than 1200x800" might be a good rule.

 

[Erik DeBill]

Much of the upper 2/3 pictures has no detail and no matter how large it would be, little would change except how one shows tonality.

I'd like to hear other opinions.

This is exactly what I'm playing with in this image. I'm trying to use the sharpness of the foreground to draw attention to the ice covered grasses and rocks, while still hinting at detail in the background. That's also why I wanted to post this image for comments (and I'll probably do that after a little more manipulation).

So far, the main thing I've learned is that the correct degree of out of focus blur is dependent on how large a print you're going to make. If its too small, the background won't seem soft enough. If it's too large, the blur becomes displeasing.

That and that I need a better viewing wall. My current solution just isn't cutting it for this.

 

[Ray West]

Hi Erik,

I'm thinking that if the final destination is print, then the effect you are after is not likely to be seen on a web browsing vdu. Never mind the colour matching issues, but a pixel at a vdu resolution of 100 dpi - my current display is 16 inches wide - then printing at say 300dpi is an equivalent area of 9 pixels. Overall subtlety in printing will not show on any reasonably size vdu image.

On the qimage site, there are some interesting examples of various sizing algorithms. Although qimage is for windows, I think the examples and text on the site are visible on other platforms.

Best wishes,

Ray