DPI in photoshop

Comments

GlennChan wrote on 2/23/2010, 6:56 PM
Scanning at higher resolutions above 400spi deteriorates the image similar to oversharpening.

Re-read John Meyer's excellent post. Perhaps you are defining terms differently than he is... but he is right. You can run your own tests and figure it out for yourself. Take a scanner, try it different ways, and see what works the best. e.g. scan some slides or negatives at 300dpi and at 100dpi... see what looks better.

2- I don't mean to be insulting or anything like that, but you are (unintentionally) going to drive a lot of people on this forum insane.
wombat wrote on 2/23/2010, 7:37 PM
johnmeyer's advice is spot on.

Ultimately what counts in scanning is the number of pixels you need to meet the end purpose of the scan, which might be many things: video, DTP, ink-jet photo print, the web, archive etc.

If you do not capture enough detail in a scan for a particular purpose, you will never get that potential detail back, even by upsampling.

So whenever you scan, do so with the future in mind. You just might want to use the image for something else later. There is not much point in scanning anything now with the shorter axis less than about 2,000 pixels - unless you will never use the image again, and you really know what you want. Archiving is cheap!

With some 30,000 scans behind me, I very much regret, now, the low-density images I captured in the early years of digital imaging. There has been no alternative but to re-scan those that I need and can still find the source. However, at the time, scanning was a very much slower process, archiving was expensive, and early computers could take maybe a minute to fill the screen with even a small jpg image, so there were disincentives to capturing in higher resolutions.

If you want to keep images, do a decent size scan, or your efforts will be near useless in a few years time.
Former user wrote on 2/23/2010, 8:25 PM
72 DPI started with the early days of the Apple Monitor. Apple came on strong with graphic support and thus became a standard for graphic use. The first Apple monitors WERE 72 DPI.

I guess we are confused by what you mean by "upsampling". As others have stated, you should scan at the rate that fits the project, and ignore SPI or DPI. The final resolution of the image is what is important.

Scanning at above 400 spi should not deteriorate the image. For print I routinely scan at 600, but for TV with normal size pics (4 x 5 or 8 x 10) this usually results in an image of too high a resolution for TV use. It is best to not let Vegas downrez the image anymore than necessary. This is not its strong point. Better to use a photo program for that. If I plan on zooming or movement I usually make the resolution twice the video rez (which I am still primarily SD so that is 2 x (720 x 480).

Dave T2
BudWzr wrote on 2/23/2010, 8:56 PM
Hahaha, I give up. Me and the OP are talking about photos and you people are talking about negatives and postage stamps, and then somebody says I'm driving him crazy???

NewBlue knows the feeling too, at least I'm not alone.
John_Cline wrote on 2/23/2010, 8:59 PM
Do you mean "give up" as in you're not talking about this subject any more or do you mean "give up" as in you're going to go out and throw yourself off a cliff? I know which one gets my vote.
BudWzr wrote on 2/23/2010, 9:01 PM
Hahaha, I feel like I'm getting hazed like in college, or jumped into a gang, hahaha.

Am I on candid camera? Or TMZ?
UlfLaursen wrote on 2/23/2010, 9:23 PM
Thanks for the great info in your posts, John M. I really value your great knowlegde here in this forum. :-)

/Ulf
Former user wrote on 2/23/2010, 9:33 PM
BudWzr,

I did not respond in order to encourage you to "give up". I wanted a clarification of what you meant by upsampling.

I agree the OP may have been questioning DPI in reference to a photo, but your first response was about computer resolutions, so it appeared that you were not talking about photos, but were talking about monitor resolutions. So I guess some of us got confused about your responses.

Dave T2
BudWzr wrote on 2/23/2010, 9:59 PM
"Resampling" is the correct term for "Up-Rezzing" or "Down-Rezzing". I use PhotoShop CS3 and Corel PhotoPaint X4 a lot, and you will not find "Up-Rezzing" in either, but I understand what they mean, I don't know why UpSampling is not understood too.

And I told all these people that I sometimes mix up paragraphs or ordering of things and that I don't do it on purpose, but they keep discriminating against me because of my problem, and report me to the mods, and I've already been suspended twice, and I'll probably get banned, and I don't understand it.

I spent a LOT of time last night thinking deeply about a possible bug in Vegas concerning mixing up subclips, and the thread got abandoned by everyone and I felt like an idiot, but I was only trying to help.

I get so frustrated here sometimes, but I DO learn a lot.
farss wrote on 2/23/2010, 10:43 PM
"And I told all these people that I sometimes mix up paragraphs or ordering of things and that I don't do it on purpose, but they keep discriminating against me because of my problem, and report me to the mods, and I've already been suspended twice, and I'll probably get banned, and I don't understand it."

What you mean is you want to be discriminated "for" because of your problem.
You could very easily address your problem by not hitting the "Post Message" button immediately, take a break after you've typed your reponse, come back to it, read it and see if you've typed what you meant to say. If it doesn't make sense to you it's darn well not going to make sense to anyone else.

Less, more considered and proof read posts will win you respect, aimless badly worded missleading / wrong posts will cause people here to understandably give you grief.

Bob.
BudWzr wrote on 2/23/2010, 11:04 PM
Well Bob, I remember the time you made fun of me by saying "... it was the OCD", and I don't HAVE OCD, but that's the point, that there's no tolerance of less than perfect responses.

That comment was hurtful, but I let it go. Why don't YOU wait before hitting the send button? You're normal right? Should be a lot easier.

I'm not the little "retarded" kid that you can kick around and make fun of to make yourself feel better. Thank goodness I don't have Tourettes.

Anyway, I'm doing the best I can.
Grazie wrote on 2/23/2010, 11:44 PM
> Anyway, I'm doing the best I can.

Sure, I understand.

Best regards

- g
farss wrote on 2/24/2010, 12:24 AM
" I'm doing the best I can. "

So are we but everyone has a limit to their tolerance. You want understanding then you've got to take as you give.
If you keep making fun of us it's only reasonable to expect a bit back. In fact most people would take that as being a sign of acceptance not derision.

"You're normal right?"

Good grief NO. Please, call me anything but not THAT.

Bob.
BudWzr wrote on 2/24/2010, 10:10 AM
Haha, OK. I thought you were for a minute there.

============================
"You're normal right?"

Good grief NO. Please, call me anything but not THAT.
GlennChan wrote on 2/24/2010, 11:47 AM
BudWzr, it seems like you mean well but other people mis-interpret your posts.

e.g. you mean well and try to start a funny off-topic thread on the forum... I read "interview with evander holyfield" and was expecting, you know, an interview. I was a little aggravated at the misleading thread subject and did not find it amusing. You have to think about things from somebody else's point of view.

I don't mean to put you down or insult you. It seems like you have good intentions, it's just the execution that is lacking...