I get it, Bob. Saving the pic at full resolution is the obvious answer.

When I import stills into Vegas however, I usually resize the pngs to 2x SD TV resolution of 72 dpi - to give a little room to pan/crop/zoom/animate without having huge files.

To import a still into a Vegas HD timeline and allow the same animation options, is there rational nexus that leads to a similar guideline? Is it even necessary? Am I only illustrating my HD-beginner-ness.

Darryl

I set my Sony still camera to 2200 x 2200 and can do about an 8 to 1 zoom in V5 without too much degradation. It makes for really big pictures though and sometimes I have to resample them down a bunch. I probably should drop down to 2000 x 2000. You will still eat memory like Grog though at these sizes.

JJK

DGrob,

Farss is right, DPI (dots per inch) is absolutely meaningless when talking about video, it's all about pixels. Television isn't 72dpi, it isn't DPI anything..

However, DPI does come into play when printing or when using a scanner. In the case of the scanner, you use DPI to determine how large the scan will be in pixels. Let's say you have a 4"x6" photograph, if you scanned it at 300dpi, then the resulting image would be 1800 pixels wide by 1200 pixels high. This is fine for standard-def DV. If you're scanning for an HD project, you might want to scan at 600dpi, which would produce a 3600x2400 image. Nevertheless, once you have scanned the image, you are through dealing with it in DPI, it's all about pixels from this point forward.

If you wanted your stills to be twice the size (in pixels) as your 1920x1080 HD project in order to have some room to pan and crop, then they would have to be at least 3840x 2160

If you're talking about a 720x480 NTSC project, then the images should be at least 1310 x 960. This is taking into consideration the difference between the square pixels of a scan or digital photograph and the rectangular pixels of DV video.

If the images were taken with a digital still camera, I'd just leave them alone and use the original image. Even a 2 megapixel camera produces 1600 x 1200 images.

John

Thanks John. I understand. Darryl

For those who are saying DPI means nothing... how do you scan your pics in? 0dpi?

Bowman01,

Re-read my post above where I discuss scanning using DPI.

John

Bowman01, what size is your picture? Oh, you didn't say. Hmmm. Without that information, dpi is meaningless.

Lets say you are shooting for 1920x1080 resolution ... if you are scanning an 8x10 photograph then you would only need 192dpi to fill the frame. On the other hand, if you have a wallet-sized photo and you want to zoom in on someone's face that is only 1/4" high, then you'll have to scan at 4320dpi. 192dpi vs. 4320dpi ... which is right? It depends on the size of the image and what you want to do with it. Once you have it scanned all that matters is the pixel meaurements of the image; dpi doesn't matter anymore.

And no, video is not 72dpi. I see so many people mention that. I don't know where that bit of misinformation came from, but it is meaningless. There is no dpi associated with video.

To be fair this dpi thing is SO ingrained in the graphic arts world it's no wonder there's a lot of confussion about it. I had a pretty heated discussion with a high end lab last year over scanning negs. Their price list only says things like A2, A1 or A0 resolution. That really threw me. What they mean is 300dpi at A0 output size, makes sense if you're working in print media but pretty useless without a bit of arithmetic if you're working in video!
It took a bit of talking to finally get them to respond to what I thought was simple question. "How much to scan my negs at the max res you can"
The answer if anyones interested was around $500, yip per neg! The resulting file from memory was around 1 GB. These were 1/4 frame negs, I think film has still got a bit of life left in it.
Bob.

"And no, video is not 72dpi. I see so many people mention that. I don't know where that bit of misinformation came from, but it is meaningless. There is no dpi associated with video."

It comes from computer monitors at one time being thought of as 72 dpi devices. I think this concept originated on the Mac a looong time ago, but it lives on as an urban myth even today.

As already stated, dpi is for printing only (on a non-stretching material :O).

I'm thinking of measuring the dpi on my HDTV 110" projection screen, it's probably something like 12-20 dpi... Yet, it looks razor sharp at viewing distance.

I was just curious because when u do scan in a photo, u do have to type in a dpi figure. I understand that video doesn't use dpi but to say that it is meaningless is hard to grasp for some when at one stage of getting a photo digitzed it has to be used.

Furthermore, usually when people scan in a photo it is used within a video it is cropped, this means that if u scanned in a photo at the exact dimensions so that at 100%, if u do any sort of zooming or cropping your gonna be off and have some sort of pixelation. The hardest thing is that when we use photos in video we don't know exactly until we have it on the timeline and how we would like to crop or zoom.

This topic is most confusing because there doesn't seem to be any EASY method of just scanning in at a particular dpi. if u have hundreds of photos at different sizes and orientations it becomes quite impractical to calculate the dimensions for each and then work out the different resolutions to scan each one in at. There must be a better answer to this than just saying dpi is meanlingless.

Just in reponse to the 72dpi issue, i learnt at design school that it is used because its a good resolution for on screen images because at 100%, pixelisation does not occur and the file size is quite miniscule. It is the minimum that most modern monitors use... appears to vary from 72-96dpi... this is the range of resolution used by web designers. go on right click and save one of the graphics from this site and view it photoshop and check the res.

Seriously, DPI, or more accurately, PPI (pixels per inch) has no real bearing on images viewed on a computer monitor or a television. It is ONLY a factor when you are scanning or printing. Here is a web page with dozens of links and tutorials that explain the concept:

DPI explained

John

bowman01: Good art is not easy. If it was, everyone would be doing it.

I suppose you could simply scan everything at 2400dpi and hope you've got enough even for those times you are zooming in on small sections. This may not be enough. It may also be too much since Vegas slows down marketly when handling large numbers of large images.

Presumably you might have an idea at the time of scanning what you are planning on doing with the picture in the video project and this can help you decide if extra resolution is needed or not. It is also possible to go back and rescan a photograph at a higher resolution if you decide after working with it on the timeline that you need more resolution.

In short, there is no "magic number" that we can give you to answer the question of what dpi to use. You do have to figure it out for yourself depending on your photographs and how you are going to use them.

addendum: DPI is meaningless when out of context. It only has meaning when the image dimensions are also included. Since the dimensions of the part of the photograph you need are unknown until you want to use it, dpi is meaningless until the context of those dimensions are known.