IMAGE SIZE JPG VS. RAW

[Kevin]

I am starting to shot more in RAW and us CS2 to tweak them in. I am a long time user of PS and have found it to be somewhat easy to make adjustments. I have noticed that with a JPG file it comes into PS at 48 in. x 32 in. at 72 P/I and with the RAW file setting at 240 P/I 8.2 mp it comes in at 14 in. x 9 in.. When I print large format or crop in the resolution goes out the window. Can someone shed some light on this subject, cus'en I need enlighten.

[robertwgross]

I am starting to shot more in RAW and us CS2 to tweak them in. I am a long time user of PS and have found it to be somewhat easy to make adjustments. I have noticed that with a JPG file it comes into PS at 48 in. x 32 in. at 72 P/I and with the RAW file setting at 240 P/I 8.2 mp it comes in at 14 in. x 9 in.. When I print large format or crop in the resolution goes out the window. Can someone shed some light on this subject, cus'en I need enlighten.

You have an 8.2 megapixel image one way or the other way, right? The image is 3504 pixels x 2336 pixels either way, right? JPEG is only slightly lossy, but other than that, it is the same image either way, right?

The 72 or 240 DPI tag is just an artificial tag placed in the file by the camera, and it really doesn't make any difference until you print. For most of us who shoot RAW, the RAW converter can be set to convert to TIF or JPEG and change the DPI setting to be 300 or anything you want. Read the FAQ on this.

---Bob Gross---

[Kevin]

Bob,
That does make perfect sense. But if I change the DPI to 300 or say 400 the image does get larger, but do you lose resolution in the image? My JPG'S look great, but since it is a flat image corrections are more difficult in CS2. I use the info button to check for exposure and I use the graph to see if the shot covers the range evenly. Thanks for the input it does help understand RAW processing.

[robertwgross]

Bob,
That does make perfect sense. But if I change the DPI to 300 or say 400 the image does get larger, but do you lose resolution in the image? My JPG'S look great, but since it is a flat image corrections are more difficult in CS2. I use the info button to check for exposure and I use the graph to see if the shot covers the range evenly. Thanks for the input it does help understand RAW processing.

Did you read the FAQ?

If you convert the RAW image to TIF or JPEG at 300 DPI, then it converts it that way without any resampling. On the other hand, in CS or CS2, if you make the change, you want to know whether you are resampling or not. If you were trying to produce a really large print (like 16x20 inches) then maybe you want to resample-up to make more pixels. However, for normal size prints (like 11x14 inches and smaller), you have plenty of pixels to work with, and you don't need to fool around with resampling upward.

---Bob Gross---

[Kevin]

Thanks Bob,
I did read the FAQ, but after I my last thread. I See what you are talking about and it makes since to me now. Most of my prints are 11x14 and smaller.

Thanks again,

[robertwgross]

Most of my prints are 11x14 and smaller.

That's normal. If you shoot RAW, then stick that 300 DPI number in as a default at the RAW converter. If you shoot JPEG, then there is probably a way to make that an action that affects a whole batch.

To me, 300 DPI is a nice round number that I don't have to worry about or think any further about. It covers me for most of the printing I do. If I need to do some resampling up, then I do that for a few. Don't worry about it.

---Bob Gross---