topic Re: Question for submitting photos in General Discussion

Question for submitting photos

Tintype_18 — Mon, 14 Nov 2022 19:10:02 GMT

I have a commission to write an article based on a presentation I gave at a writer's conference recently. I understand the requirements: 4x6 and jpeg format. Need some clarification on two things: required 2mb in resolution (how do I confirm this?), 300dpi (certain of this as dots per inch) but how to confirm this. Hope I have presented this clearly. If not, let me know. Thanks.

Re: Question for submitting photos

rs-eos — Tue, 15 Nov 2022 03:51:02 GMT

2 MB in resolution seems to be an odd way to phrase things, however, for a 4 x 6 image at 300dpi, that would be 1200 x 1800 pixels or 2.16 million pixels.

Re: Question for submitting photos

FloridaDrafter — Tue, 15 Nov 2022 04:35:28 GMT

I agree, Ricky. I think they, or John, means a 2mb cap on file size.

Newton

Re: Question for submitting photos

Tintype_18 — Tue, 15 Nov 2022 15:08:56 GMT

Thanks. The 2mb is on their guidelines. Thought it was kind of odd, too.

Re: Question for submitting photos

ebiggs1 — Tue, 15 Nov 2022 15:59:32 GMT

"...4x6 and jpeg format. ... required 2mb in resolution ..."

Neither 4x6 nor 2mb is a resolution spec. I suspect they want 4x6 photos and they have a limited amount of storage space so they put a 2mb file size limit. I would make my 4x6 photo look the best it can while watching the size limit.

Keep in mind DPI is a printer spec. Folks generally will discuss digital images in terms of DPI which seems to be OK or accepted at least the way things have gone. It is calculated by dividing the total number of pixels wide by the total number of inches wide. In your case you have a digital image that is 1200x1800 pixels and is 4x6 inches in
size. Your photo has 300 DPI. Divide the number of pixels wide by the number of inches wide. Remember DPI is dots per inch. Whether this results in a 2mb file is not known.

Re: Question for submitting photos

ebiggs1 — Tue, 15 Nov 2022 16:11:37 GMT

Perhaps this may clear it up a bit more. If you take the very same 4x6 inch photo at 300 DPI and blow it up to 8x12 inch, it now has a DPI of 150. But it is the very same image. Usually for nice looking prints you want to stay in that 150 to 300 DPI range. So, you see DPI is a relative term.

Re: Question for submitting photos

rs-eos — Tue, 15 Nov 2022 18:22:09 GMT

Dots and pixels though can be used interchangeably in this context. And since both physical size and DPI values are given, resolution can be obtained.

Equations become:

4 in x 300 pixels / in and 6 in x 300 pixels / in

The units of inch cancel and the final values (1200 and 1800) are now in pixels.

You're most likely correct that there's also a file size limit of 2 MB. I know that Adobe Illustrator has in its export options the ability to constrain an image to particular dimensions while also capping the file size. Other applications may also provide a preview/estimate of the resultant file size based on the JPEG quality setting.

Re: Question for submitting photos

ebiggs1 — Tue, 15 Nov 2022 21:59:22 GMT

Whether the two are interchangeable or not, technically they are not, software like Photoshop don’t help by confusing the situation including DPI in the Image size box.

A big reason for all the confusion is how intertwined PPI and DPI are. A whole lot gets lost in translation when moving from screen to paper. Remember these facts. Pixels are not dots and DPI is not the same as PPI.

PPI is the number of pixels per linear inch of a digital monitor. This is the image’s resolution.

DPI is a measure of the printer’s resolution. Every digital image has a set PPI, but an image doesn’t have a set DPI until it is sized for printing.

There are two ways to increase the size of an image, add more pixels or make the pixels themselves larger. Also, you can reduce an image’s size by shaving off pixels or shrinking pixels. Shrinking and shaving are two different abilities. Resizing an image changes the actual size of its pixels, but not the number of pixels. Resampling changes the image’s size, larger or smaller, by increasing or decreasing its total number of pixels. Photoshop’s Image Size box controls both resizing and resampling.

If you make an image in PS that is 600 pixels wide and 400 pixels high and set the DPI to 72, it is 240,000 pixels. Make another image also 600x400 but at 300 DPI. It is still 240,000 pixels. Because 600x400 remains 240,000 pixels. The DPI doesn’t make a difference because we are not printing the image.

Re: Question for submitting photos

ebiggs1 — Tue, 15 Nov 2022 19:40:23 GMT

Any place or organization that is photography literate at all will not ask for images by DPI. At least they should not!

Re: Question for submitting photos

Tintype_18 — Wed, 16 Nov 2022 14:00:54 GMT

I'm was just passing along what the photography guidelines included. That is why I made this thread to get feedback from the forum members. I'm going to finalize the text today or tomorrow and work on what photos I have. Again thanks to all.

Re: Question for submitting photos

ebiggs1 — Wed, 16 Nov 2022 15:10:46 GMT

"I'm was just passing along what the photography guidelines included."

You run into this all the time. Basically people do not understand the difference between DPI and PPI. It is not uncommon at all. To make it worse there is lots of misinformation. It's no biggie just make sure your submissions are as good as you can and keeping the total file size under 2MB.

Re: Question for submitting photos

Tintype_18 — Thu, 17 Nov 2022 21:04:46 GMT

Here are my spec's on one photo I'm looking to submit: 3264X2448, 3.92 MB.

I'm quoting the guidelines (should have done this first): "All photos must be at least 4" by 6" in size, with a minimum of 300 D. P. I. quality."

The 2 MB minimum is for any photo considered for the magazine cover. We'll address this later.

Again, many thanks for your help, now and in the future.👍

Re: Question for submitting photos

ebiggs1 — Fri, 18 Nov 2022 16:42:55 GMT

Your dimensions would yield a photo that is 8x10 if the DPI is 300. You will need to reduce that to 1800x1200 at 300 DPI for 4x6. Whether that yields a 2MB file size?

File size is determined by the number of pixels. You need to find out how many pixels the image contains. Since the resolution is 300 dpi, it means that each inch is 300 pixels across. Up and/or down. As the image is 6 inches wide that means there are 1800 pixels in width (6 x 300). And the image is 4 inches tall. 1200 pixels (4 x 300). To get the total we multiply the width and length. The answer is 7,990,272 pixels. How big is the file? We now know how many pixels are in the image. Right? A grayscale image each pixel is 8 bits or 1 byte in file size. Color is 3 times that. Your 4x6 photo at 300 DPI will be about 6MB. 1/3 that for a grayscale photo.

You can see this info in Photoshop in the Image Size box.

Of course this doesn't consider jpg compression, jpg typically achieves 10:1 compression factor albeit with a little loss in image quality.

Re: Question for submitting photos

Tintype_18 — Fri, 18 Nov 2022 19:36:14 GMT

Thanks for the info. Will print for future reference as my memory isn't as good as it was. Can't remember who told me. Many of my photos are old jpg photos. Will see what I can come up with here.

Re: Question for submitting photos

Tintype_18 — Sat, 19 Nov 2022 19:51:46 GMT

EB and others, thanks again for the info. I submitted the photos this morning and trust they will be acceptable. One last question on this: When one edits an original photo regarding pixels, can can the photo be restored back to its original pixel count?

As an aside, I'm going to make sure I have my good camera for taking photos of any outdoor activities to avoid the low resolution photos from the P&S camera.

Re: Question for submitting photos

ebiggs1 — Sat, 19 Nov 2022 20:31:44 GMT

"...can the photo be restored back to its original pixel count?"

No, it is only original once. Best practice is always shoot Raw. Always work on a copy.

Re: Question for submitting photos

Tintype_18 — Sat, 19 Nov 2022 21:41:16 GMT

That is what I thought but needed an expert opinion. Keep the RAW photo as the original and edit with the copies, I'm thinking.

Submitted photos along with thanks to all!

Tintype_18 — Sun, 20 Nov 2022 18:52:45 GMT

First, thanks to all who replied and contributed. As I said many of the relevant photos were taken with a low resolution P&S camera. Making it a practice to use my T7 with RAW and edit accordingly with PSE2021 and DPP4.

I got an email this morning from the editor and "The photos were great" (his words).

Re: Question for submitting photos

ebiggs1 — Sun, 20 Nov 2022 19:14:32 GMT

My practice is to u/l to my computer. Make a copy that goes right to my external back up HD. It remains and has remained unmolested ever since I have had it. Photoshop lives on my main C: drive where edits are done.