Optimizing Photos for the Web

Here's my next hurdle: Am I getting the most quality into the pictures that I post in my photo forums? I have not been using PaintShop Pro 9 optimizer feature because I found the instructions pretty confusing.

I take photos in high quality jpeg format, then convert them to psp files for processing. The files begin as huge images: 36"x24" set at 72 ppi, which makes them 2304 pixels x1728 pixels

Before converting back to jpeg, I do a resize:

Resample with "Smart Size"
Resolution: 72 ppi
Aspect Ratio is locked
For landscape format, I set the width to 11"
For portrait format, I set height to 9.5"

I reconvert to jpeg by saving as jpeg, then post.

However, I see that other photographers' images are much higher in resolution---like 300 ppi, but much smaller in height and width---say 1.7" x 2.7".

Can't help noticing that both our images appear on the forum as being close to each other in size---so the host must be standardizing the appearance somehow. My choice of 11" and 9.5" as dimensions had more to do with the assumption that what I chose is pretty much the size that was showing up on the screen. That seems like a misunderstanding now, though.

My camera is one of the little advanced compacts- Panasonic FZ7--so for a long time I assumed that quality differences between my shots and the ones these other guys were taking had to do with both their own greater skills, the higher quality of their cameras (plus more experience in post processing).

But I'd like to make sure that I'm not making some unintentional choices in the resizing, or failure to use the optimizing features of PSP, that are reducing the impact of my shots---that is, less sharp, less difference showing up in the tones, etc.

I would be very appreciative of any help anyone can offer in helping me understand what's going on.

Thanks in advance.

Hi Soenda, Can you post a link to a couple examples?

Are you hosting the pictures from Pbase and providing a link (in a thread) to your forum or are you actually uploading the file directly to the forum server?
If you host from Pbase and provide a link in your forum thread, you don't have to have the same level of compression. Directly posting to the forum server normally has pretty strict file size limits, which can be tricky to meet and retain quality.

Anyway, I would suggest selecting the Pixel option when resizing, vice inches. I've found 600-700 pixels on the width tend to be a nice size for most browsers. You really have to experiment with the level of compression you need. Quality is really an idividual thing, only you know what's acceptable. Using the optimizer to meet forum restrictions on file size is probably the best way to go.

I'm not sure why you would convert your JPEG's to PSP files? I would suggest working directly with a copy of the original JPEG, unless of course you do a lot of work on them and resave many times.

I'll share my process. I'm not suggesting my images are of the highest quality, but it may help get you in the acceptable direction.

I shoot all RAW, so I'll leave all those steps out.
-Put your JPEG into PSP
-Crop if necessary
-Resize
-Make appropriate color adjustments
-Sharpen (experiment with High Pass and USM)
-Save (I don't post directly to a forum server, so I use the minimum compression for my images on Pbase)

good luck

I'm happy to post a few links for comparison. I just visited your pet gallery and discovered that you are using the same combination of high resolution and smaller side dimensions that I was talking about above. Your dog shots are delightful, by the way. I hope you won't mind be including a couple of those links, too. I presume that I am posting to Pbase exactly the same way you are. When I post to other forums, it's generally with a link back to pbase, not to the image on my hard drive.

Here are mine, which were set at 72 ppi resolution:

http://www.pbase.com/soenda/image/74357902 (132.86 KB) (note: it's snowing in this one, which could confuse the sharpness issue)
http://www.pbase.com/soenda/image/70668362 (189.9 KB)

and here are two of yours (just beautiful, btw)
http://www.pbase.com/tcimages/image/56011801 (300 ppi/438 KB-Canon 350D w/flash)
http://www.pbase.com/tcimages/image/72821337 (350 ppi/532 KB-Canon 30D)

These perfectly illustrate my confusion.

I was under the impression that all images on the WWW were rendered into 72 ppi by the hosts, and that if you post an image at 300 ppi, the host's software compresses it.

Your photos show relatively small physical dimensions, mine are 10 times larger, but they all appear on Pbase as roughly the same size. Again, I assume Pbase is doing something to adjust that.

Your images are wonderfully sharp. Mine are softer. So:

1. Are your photos really being displayed at 300 and 350 ppi? If that's the case, why is it so often said that 72 ppi is the default resolution?

2. Am I getting lost in the difference between screen resolution, 72 dpi and the photo resolution, expressed in ppi?

3. Is the apparent quality difference due to the difference in our cameras, the Panny FZ7 vs the Canons?

4. Would you recommend that I start shooting my images in tiff format and sizing them at 300-350 ppi when I convert to PSP to process them? I see that you recommended that instead of physical dimensions you say that I should set the resizing with the pixel dimensions, but I'm not clear on whether or how that actually shows up on viewers' screens.

My conversion of jpeg files to psp is because of the amount of work I do on them. Who knows...maybe if I didn't convert them, I wouldn't have to do so much work? But I was under the impression that to use tools like layers in PSP, the files did have to be in the proprietary format. And it's what I was advised to do back when I was getting started, so really it's a matter of "that's how I've always done it." I'm completely open to suggestions.

Thank you very much for wading through all this. It's hard for me get my questions into words, so I apologize for the lengthiness. But I feel that if I can finally understand these things, it could make a big difference in how my photos come out. Your help is much appreciated.

To add to my confusion, I just found that my own monitor screen's default setting is 96 dpi, not 72 dpi.

And yet Robin Nichols says in the PSP 8 guidebook that I use:
All web pictures are set to display at a resolution of 72 dots per inch. This is because it's because it's the default resolution of the screen that displays web pictures. If you present a picture with a higher resolution than this, you won't see any quality benefit, all that'll happen is that the picture will display too big in the browser! Plus, it'll take ages to download..." page 236

Arrrgh! :p

Ok, I try to point out a few things that may help you.
First, I think you may be confusing Pixel Demensions with Print Size. I have to be honest, the whole PPI, DPI thing can be very confusing and you really don't need to be concerned with it unless you plan to print your resized images, Print size allows you retain print quality while resizing. This is something the folks on here are probably experts at due to printing graphics and may be able to add info.

I would focus on the Pixel Demensions. In my image below, the black arrow is identifiing this in the resize prompt.

Now, on to some other points.

The pics you posted- To me, these aren't post processing issues, but focus issues.

First Image - I think you missed the focus in this image. If you look closely, it seems the focus point is on the bushes on the left. Also, There is considerable motion blur due to adequate shutter speeds.

Second pic - This is using an aperture of F2.8. This allows a faster shutter speed which can help with motion blurr, but creates a VERY shallow DOF (Depth of Field). This is the area in front of and behind the focus point. I think your focus point is just in front of him and the shallow DOF, did not allow for his face to be in focus.

Focus Points - If your camera have multiple focus points, turn them all off accept for the center one. This is the biggest cause of a missed focused.

Camera differences - There can be a big difference in image quality based on the cameras used. SLR's offer more flexibility in the settings as well as higher quality lenses over Point and Shoot.

Files Formats - I personally would advise you to just use the JPGs, not convert to PSP. However, if you do extensive manipulation and plan to save several times, use the PSP format.
If all you do is make some quick adjusments, use the JPG. I tend to use the Smart Photo fix and make all my adjustments there (click the advanced button).

If you want, post an original of one of these images on PBASE and I'll post process it to see if my method is any better.

Quote:

---

Originally Posted by soenda

To add to my confusion, I just found that my own monitor screen's default setting is 96 dpi, not 72 dpi.

And yet Robin Nichols says in the PSP 8 guidebook that I use:
All web pictures are set to display at a resolution of 72 dots per inch. This is because it's because it's the default resolution of the screen that displays web pictures. If you present a picture with a higher resolution than this, you won't see any quality benefit, all that'll happen is that the picture will display too big in the browser! Plus, it'll take ages to download..." page 236

Arrrgh! :p

---

In actual fact it makes no difference what ppi you set in an image that is viewed on a monitor or tv. each uses there own resolution. What does make a difference is size in pixels. a 800 x 600 image viewed on a 1024 x 786 screen will fill about half the screen but will fill a 800 x 600 screen and also be two big for a TV but not a HD TV which is more like a computer screen. As you say your viewing your fonts at 96ppi but what the ppi of the screen is depends on its width in inches divided by the resolution set in pixels. for example the average 17" inch screen is 11inch in width and the averag user runs it at 1024 x 786 giving 93ppi.
That said you only need to alter the ppi when you want to make a print. Its no more than a printing factor pixel dimension divided by ppi =inches just like pixel dimension divided by inches = ppi.

My method was raw converted to tiff opened in psp and saved as pspimage after any enhancement the same image was the resized to 720 x 566 for use on the web or in a DVD slide show. Note that's Pal size for the UK, across the pond its a little smaller so 800 x 600 for the web is about right.

I hope thats of some helpand not too much
Trev

Quote:

---

Originally Posted by Crypto

Ok, I try to point out a few things that may help you.
First, I think you may be confusing Pixel Demensions with Print Size. I have to be honest, the whole PPI, DPI thing can be very confusing and you really don't need to be concerned with it unless you plan to print your resized images, Print size allows you retain print quality while resizing. This is something the folks on here are probably experts at due to printing graphics and may be able to add info.

I would focus on the Pixel Demensions. In my image below, the black arrow is identifiing this in the resize prompt.

Now, on to some other points.

The pics you posted- To me, these aren't post processing issues, but focus issues.

First Image - I think you missed the focus in this image. If you look closely, it seems the focus point is on the bushes on the left. Also, There is considerable motion blur due to adequate shutter speeds.

Second pic - This is using an aperture of F2.8. This allows a faster shutter speed which can help with motion blurr, but creates a VERY shallow DOF (Depth of Field). This is the area in front of and behind the focus point. I think your focus point is just in front of him and the shallow DOF, did not allow for his face to be in focus.

Focus Points - If your camera have multiple focus points, turn them all off accept for the center one. This is the biggest cause of a missed focused.

Camera differences - There can be a big difference in image quality based on the cameras used. SLR's offer more flexibility in the settings as well as higher quality lenses over Point and Shoot.

Files Formats - I personally would advise you to just use the JPGs, not convert to PSP. However, if you do extensive manipulation and plan to save several times, use the PSP format.
If all you do is make some quick adjusments, use the JPG. I tend to use the Smart Photo fix and make all my adjustments there (click the advanced button).

If you want, post an original of one of these images on PBASE and I'll post process it to see if my method is any better.

---

Thank you very much for this insight.

1. Yes, I have been confused about screen size vs. pixel size. I'm still not sure where the 72 ppi resolution enters my photos---whether it comes from the 6 meg, high quality setting I use on my camera, or a setting I opted for early on in PSP. I'm guessing that your 300 ppi resolution comes from your RAW files. When I adjust my resizing options to 700 pixels wide, for example, the 72 ppi value stays the same. I tried resizing a "fresh-from-the camera" jpeg and comparing it at 300 ppi with a 72 ppi version of the shame shot, and couldn't find any real difference. Interesting, since the larger file takes up so much space and delivers no quality improvement in return.

2. I think you are quite right about focusing problems, and indeed, I had been using the nine area AF setting. I have been frustrated trying to use the manual focus of the Panasonic FZ7, but it's awkward. Someone did suggest that the EVF and LCD screen themselves do not offer enough resolution for good manual focusing. That means that I probably won't be able to beat the softness problem manually---so I'd better learn how to make the most of AF. I will shoot my next batch with the single, central point focus AF setting.

3. For the time being, I'll probably stick with using the PSP format for editing. I do a lot of fine tuning and a fair amount with effects. It would be different if what I shot at any one time was pretty similar---like a wedding, or a party---but it isn't. I'm all over the place.

4. Thanks for the offer to try processing one of my images. Let me wait and pick one that I can really benefit from getting a different approach. Since your better processing skills won't help my focus problems, I want to make sure I'm asking for help where it will make a difference.

I appreciate all the time and thought you've given this very much, Crypto. Many thanks.

Quote:

---

Originally Posted by Trev

In actual fact it makes no difference what ppi you set in an image that is viewed on a monitor or tv. each uses there own resolution. What does make a difference is size in pixels. a 800 x 600 image viewed on a 1024 x 786 screen will fill about half the screen but will fill a 800 x 600 screen and also be two big for a TV but not a HD TV which is more like a computer screen. As you say your viewing your fonts at 96ppi but what the ppi of the screen is depends on its width in inches divided by the resolution set in pixels. for example the average 17" inch screen is 11inch in width and the averag user runs it at 1024 x 786 giving 93ppi.
That said you only need to alter the ppi when you want to make a print. Its no more than a printing factor pixel dimension divided by ppi =inches just like pixel dimension divided by inches = ppi.

My method was raw converted to tiff opened in psp and saved as pspimage after any enhancement the same image was the resized to 720 x 566 for use on the web or in a DVD slide show. Note that's Pal size for the UK, across the pond its a little smaller so 800 x 600 for the web is about right.

I hope thats of some helpand not too much
Trev

---

That makes a lot of sense, Trev. Your explanation is very helpful. I started out a year ago with an older camera with only a 1.3 meg sensor. That's probably why I've been obsessing about resolution so much.

It's funny in the end, because I don't print any pictures, at least not yet. So all this time I've been fussing about getting something right that didn't matter.

Now I can get on with trying to get better photos into the camera in the first place. Thank you very much for your help.