Sharpness in larger pictures

[magern]

Hi,can anyone help?

I know to keep sharpness in larger pictures i need a faster shutter speed and obviously be in focus,but im still uploading pictures to be printed on photobox and getting messages saying its a poor image or distorted at a larger size,say a4 for example. How can i be sure a picture i take can be blown up to a bigger size. I use my camera in shutter priority and generally use iso 400 and nearly always faster than 1/100 shutter speed,sometimes 1/800 but they still wont enlarge sharp?
any help appreciated

 

[PsiFox]

What camera and post some examples here.
A4 should not be a problem.

Some of mine have been printed at 4ft x 3ft

 

[JSER]

Agree without knowing what you are doing and using impossible to say.

I print everything at A3+, rarely below A3 and all my photos are sharp, not the examples as they are reduced for upload, but seen close they are 100% sharp, 200/400 or 800 ASA.

 

[magern]

hi using a nikon d3100.will post some examples in a while. i took some photos with a 55-200mm lens at 1/250 iso 400 f11. sharp as anything when i upload to pc but when i change sizes it loses sharpness and i cant understand why

 

[Alastair]

Sounds like the sort of message you get when you're trying to enlarge a low resolution image, i.e. the DPI at the chosen print size will drop below their quality threshold.

We need to see some samples and know the dimensions of the images you are sending to be printed.

 

[JSER]

hi using a nikon d3100.will post some examples in a while. i took some photos with a 55-200mm lens at 1/250 iso 400 f11. sharp as anything when i upload to pc but when i change sizes it loses sharpness and i cant understand why

My son has a D3100 with Nikkor VR 28-300

A3+

The original is TACK sharp.

 

[magern]

hi i just uploaded 3 pics to my gallery. how do i get them on this thread??(sorry fairly new to this forum) they are not as sharp as they have been resized but these are a few pics im having problems with

 

[magern]

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[magern]

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[magern]

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[Forbiddenbiker]

Tell us please. What size are the original images that your uploading to PB and what resolution are they?

Are these small example images, the full images or crops of them?

 

[magern]

ah both these pictures are cropped although the boat picture hasnt had much cropping done to it

 

[magern]

size of images uploading to pb are 400 x 264 with 300 resolution

 

[Merc]

What settings are you on for picture quality in your camera? Could be that it's set to low resolution or small size.

Edit... Have you put those sizes (400x264) in when cropping? If so.... don't. Change those settings to the largest, if you're printing large.

 

[magern]

hi merc.just checked camera settings and it is set to large so no problems from within the camera. just wondered if im cropping too much in editing

 

[Merc]

When you crop are you resizing by mistake or saving for web? Try cropping (Not too much obviously) again and save in highest resolution and size possible. See if that helps.

 

[magern]

yeah i will try that thanks.its the only thing i can think of. thanks for everyones comments

 

[Forbiddenbiker]

300 resolution is ok but you need to be saving your upload images for printing large, like at their original full size, or slightly reduced crops of that large size. (could be anything, say, 2000-4000pix on the longest edge)

as mark says

 

[Alastair]

A4 is roughly 12" (ok, slightly less).. at 300dpi you need about 3600 pixels (12" x 300dpi)along the long edge.. sending only 400px on the long edge is so far short of this, that's your problem.

 

[StewartR]

A4 is roughly 12" (ok, slightly less).. at 300dpi you need about 3600 pixels (12" x 300dpi)along the long edge.. sending only 400px on the long edge is so far short of this, that's your problem.

This is indeed the problem. It doesn't matter whether or not you've saved the image at "300 dpi", because that's just a tag which is written into the metadata and most printers ignore it. But what does matter is how many actual pixels you have. 300 per inch is a useful rule of thumb if you want the image to be sharp even when examined close-up, so for A4 you need 3000+ pixels on the long edge.

Try cropping (Not too much obviously) again and save in highest resolution and size possible. See if that helps.

But remember to do this on the original. If you've already re-sized it to 400 pixels, then re-sizing it back to 3000 pixels won't help, because you've already thrown away the details and you can't re-create them.