Digital Camera Education needed ...


Senior Member
I'm in charge of our upcoming church pictorial directory and need some information. We are going to try to take our own pictures and 4 people have volunteered to do this. I'm not sure about all of the details yet but I do know that one of the cameras is a 2.0 MP and another is a 3.1mp. What I need to understand is will the picture from the 3.1MP camera be more bytes than one from the 2.0 MP camera? I would assume so. My other question is can I tell my 3.1MP camera what "size" picture I want/need. If we are using 4 different MP cameras can I get a matching quality/size picture from all of them assuming I need to down sample all of the cameras to a 2.0mp sampling? The final pictures will only be approx 1.5" X 1.5" and 10 per page. I also need to understand how low a resolution I can go with any of these cameras? The smaller the file size the better.
Pretty much every camera allows you to select the quality, from low res jpg's to high res TIF or RAW files. The 2MP camera will be more than enough for the 1.5"x1.5" pictures, since your requirements are very low, you probably could use one of the lower resolutions settings.
Finally something I can help Rupp with :D
Something small in return for all his help

Most camera's have a setting for email. This would keep the size small. This is the setting I would use for 1.5" picture. Also different cams vary in compression of the picture so it would be hard to get them all the same size.

I work in printers/camera's at BB. I also have 2 cams a Sony 5 meg. and a Fuji 5.1 meg. I prefer the Sony

There are obviously many ways to do this, but I 'll explain how I would do it.

1. Find the camera with the lowest res, say 2 mp, 1.2 mp or whatever, then set all the others to the same.

2. Photoshop the pics (I have Adobe Photoshop Elements that came with my computer, but you could use another editing package). You'll need to crop them somehow to get a square image anyway.
Then resize the pictures to 1.5" by 1.5", I just tried it with a 2mp image (settings 72 pixels per inch) and it gave me a 22KB jpeg with max quality or a 18.5KB jpeg with mid quality.

Jpegs will vary in sizes according to the picture as they compress more in areas of less detail, whereas TIFF and RAW files will stay the same. Jpegs are the way to go to save space.

You could certainly do it the way BrianD explained too and it would require a fair bit less fiddling, but since you only need a very small picture, I would expect the sizes from the "email setting" to be larger. I may well be wrong though, this is only a suggestion.
This method would, IMO, be the most reliable way to make sure all pics end up with the same quality from different cams (you could probably not even bother with step 1).
There is yet another way of going about it. I am an amamteur photographer, but have had a few pictures published in the Palm Beach Post, and a couple of art directories. I do things more on the high end (around 7.0 meggapixel) but the same rules apply.

Take all the pictures at the highest resolution that the perticular camera will support. They can NEVER be "to high of quality". From there you have the best pictures posible to work with.

From there, you can use many different pictures to sample them at the same resolution. You can then resample all of them to the same size, reducing the size/quality. After the pictures are taken, it is a one way street for the most part. You can not get better quality from a low res pic, but you can easily turn a high res pic into a lower one, and thus match them up.

I saw 72 dpi mentioned in a previous post, thats great for web and computer publishing, as thats all a screen can display, but for printed photo's that would be REALLY low res and not produce good results for sure.

Printing is usually done anywhere from 300 to 1200 dpi, no matter what the picture quality is, depending on the printing company you are using.

The best way to "resize the photo's would be with photoshop, paint shop pro, ect. You can create a "template" say 350 x 450. You can then place each photo into this template, and move it around, readjusting the size to make them all look the same, as a year book does for example. As different people will be taking these photo's from varying distances ect, you will want to crop the pictures, focusing on the person in the photo only, in their original state, crop the person out as proportional as possible (Say from midchest, to top of head, and shoulder to shoulder), do give the same proportion to each of the photo's. You would then, after all photo's are cropped to be very similar, you would rescale all the images to match.

The sample pictures below were taken at my Christmas party a couple years ago.


In the sample below, To simulate a lo-res picture, the group of 5 people was resized to 640 width. Then Dan, was cropped out of that picture, then rescaled to 350 width, after cropping everyone else out. You can see it looks a bit grainy. On the other photo, I cropped out the First Lady from the original picture, THEN resized it down to 350 width. It retains all of its clairty.

This is what I mean that a photo can NEVER be to high of resolution, start big, then resample all photos to the same size and DPI and they will match. If the picture is low-res in the first place, there is not much room to work with.

I know this is a lot of info, and it is hard to really explain it here. If you want to drop me an email, I would be glad to help you out in any way that I can Greg. You certainly have helped me out many MANY times! If you are using Photoshop, I could also make a template for you, like I mentioned above.
Well said, JohnWPB. I wanted to just add that you must always have in mind the final product, and what the process is that will be used to print it. As JohnWPB mentioned, a professionally-printed directory will probably want no less than 300dpi, but more likely 1200dpi pictures. When I was doing desktop publishing in the 80's and 90's, the standard was 2400dpi for the newspaper, which they would then apply a screen to in order to print it in the paper. The high resolution was needed to minimize aliasing effects when the screen was applied.

If the directory is just being printed by a standard inkjet printer, you can get away with a lot less resolution. You could, for example, supply it on CD (maybe even HTML format) for the church members to print on their own systems. But I'm pretty sure you're looking for a professional quality print job.
OK here's an newbie question. Can you set the DPI on the camera or is this a post processing thang? I'm looking at Paint Shop Pro right now and just checked when I create a new image I have the option of settings pixels/per inch. I know how to take the raw image and resize it in PSP. How do you work with DPI when everything seems to be in Pixels per inch?
Listen to JohnWPB. Don't go to low resolution images too early. And JPEGs with a lot of compression will give you miserable looking pictures. Is file size an issue? This is related to but not strictly dependent on the resolution (pixel x pixel, not dpi).

I think the best thing to do is experiment. Get some samples from each person and see what you can do with them.
Rupp said:
OK here's an newbie question. Can you set the DPI on the camera or is this a post processing thang? I'm looking at Paint Shop Pro right now and just checked when I create a new image I have the option of settings pixels/per inch. I know how to take the raw image and resize it in PSP. How do you work with DPI when everything seems to be in Pixels per inch?
I have found that the easiest way to handle DPI is to forget DPI altogether. Don't think about it, it just confuses the issue.

Find out what size image you want (i.e., 800x600 pixels, etc.). Resize your images to this size. Now, this size may be determined by a dpi- or ppi-type number. If you know the printer will work best with 300dpi and you want a 1.5"x1.5" image, then resize to an image size of 450x450 and set PSP to use 300ppi (should be same as dpi in this case, shouldn't it?).

If you set the image's size, the dpi or ppi number does absolutely nothing to the image. It's just a number stored in a jpeg file and/or used by the program if you say you want a final size of 1.5"x1.5" (to do the calculation above). It does not affect the image itself. Some programs may use it when printing, others won't.
I wasn't sure if the small size requirements were because of storage issues with the cameras, or if he meant final size, but if you have plenty of storage, then take them as big as possible, you really can't go wrong with that, it's easier to remove/scale down content than 'add or stretch (which causes pixellation).