Check Your Images at 100%

[suziq]

Hi all

 

This is my first post and I am reasonably new to photography.  I have searched elsewhere but can't find the answer to this question.  What exactly does "Check your images at 100%
All images should be checked at 100% (actual pixels) for correct exposure, colour cast, noise, camera shake and that no sharpening has been applied etc. using professional imaging software." mean and how do I do it?

Apologies if this has been addressed somewhere else or if it's a really dumb question!

 

Thanks

Suzi

[Harry Harrison]

4 hours ago, suziq said:

What exactly does "Check your images at 100%

 

It means that you need to zoom in so that essentially one pixel on your screen shows one pixel on your image. In Photoshop this would be 'Actual pixels' and in Lightroom it would be 1:1, other software may have different ways of representing it. That way you will see any problems in terms of sharpness, noise, colour fringing etc. - and more importantly that's how QC will be looking at it as well!

 

It might be helpful to know what software you are using if it's not one of those two so that others familiar with it can advise.

 

 

[MDM]

First of all take this positively as it is certainly meant that way. As you are (reasonably) new to photography, if you find yourself asking very basic questions like this, then you should consider the possibility that you are trying to run before you can crawl so to speak. Learning the basics and having a solid grounding in photographic technique is very important if you are attempting to sell your pictures. You don't need to be professional to supply pictures to Alamy but you should be able to produce professional quality pictures. For those of us who catch the photography bug, the experience of learning is amazing and that learning should never end, no matter how long one has been doing it. There are so many people nowadays practising photography in one form or other and it is really worth getting the basics right if one wants to stand out from the crowd. While people here on the forum are very helpful, there are better places than here to learn the craft. Have a good trip 😀.

[suziq]

Thanks so much HH, am using Lightroom and appreciate your help.

 

Thanks MDM - will accept your diplomatic comments in the spirit in which they were intended.  Am very much looking forward to the trip.

Edited July 29, 2019 by suziq

[MDM]

1 hour ago, suziq said:

Thanks so much HH, am using Lightroom and appreciate your help.

 

Thanks MDM - will accept your diplomatic comments in the spirit in which they were intended.  Am very much looking forward to the trip.

 

Don't mention it suziq and great that you took what I said the way I meant it as it is very easy to be misinterpreted on forums. Don't let what I said put you off posting here either as  it is a really nice forum (for the most part anyway). If you are using Adobe software there are loads of excellent tutorials available aimed at all sorts of levels. 

[Harry Harrison]

3 hours ago, suziq said:

Thanks so much HH

Pleasure. One thing, for your first submissions do try and choose images that are unlikely to fail due to any technical reasons, so no high ISO or inappropriately low shutter speeds, absolutely no sensor spots etc. Just play it safe for a bit! Alamy might be lenient the first time, at least they were with me, but generally repeated QC failure counts against you and will mean that they will be extra vigilant with your images. Good luck, it's not that tricky really.

 

.....actually I ought to clarify that. Sensor spots will never do, ever, but they are unlikely to show up unless you are using very small apertures and even then probably only against large areas of even tone, blue skies etc. Use the metadata 'aperture' filter in Lightroom to isolate the likely suspects.

 

High ISO should be OK but it will depend on your camera sensor and you need to get used to recognising noise if there is any, and how to deal with it in Lightroom. 

 

Sharpness should be self-explanatory and differential focus from limited depth of field is fine as long as the subject is sharp, and it's obvious what is meant to be the subject. Slight softness from intentionally moving subjects is probably OK also, but maybe not for those first batches.

Edited July 29, 2019 by Harry Harrison

[M.Chapman]

8 hours ago, Harry Harrison said:

 

It means that you need to zoom in so that essentially one pixel on your screen shows one pixel on your image. In Photoshop this would be 'Actual pixels' and in Lightroom it would be 1:1, other software may have different ways of representing it. That way you will see any problems in terms of sharpness, noise, colour fringing etc. - and more importantly that's how QC will be looking at it as well!

 

It might be helpful to know what software you are using if it's not one of those two so that others familiar with it can advise.

 

 

 

A minor caveat, if you happen to be using one of those hi resolution 4K monitors (or above) or an Apple Retina display which has pixels so small you can't see them, you may need to inspect at 200%. To inspect your image at 100% it's important that you can (just about) see individual pixels in your image.

 

Mark

[geogphotos]

1 hour ago, M.Chapman said:

 

A minor caveat, if you happen to be using one of those hi resolution 4K monitors (or above) or an Apple Retina display which has pixels so small you can't see them, you may need to inspect at 200%. To inspect your image at 100% it's important that you can (just about) see individual pixels in your image.

 

Mark

 

Mark, Could you please explain more about this. You always seem to have a good grasp of technical things. I use a Canon 5D with 24-105 L

 

I have one of these monitors and although I noticed the difference at 100% when I first started I didn't really understand what was going on. I have not been viewing at 200% and this includes a lot of high ISO shots which I have reduced in size to around 26mb. I haven't had any QC problems at Alamy or anywhere else. Have I just been lucky?  Viewing at 200% now seems odd to me because I am unused to it.  Not sure whether to simply carry on or to change my workflow.

 

Thanks

 

Ian

Edited July 29, 2019 by geogphotos

[M.Chapman]

12 hours ago, geogphotos said:

 

Mark, Could you please explain more about this. You always seem to have a good grasp of technical things.

 

I have one of these monitors and although I noticed the difference at 100% when I first started I didn't really understand what was going on. I have not been viewing at 200% and this includes a lot of high ISO shots which I have reduced in size to around 26mb. I haven't had any QC problems. Have I just been lucky? Not sure whether too simply carry on. 

 

Thanks

 

Ian

Hi Ian,

 

A typical (standard resolution) display has around 100 pixels per inch (PPI)

The latest 4K, 5K and retina displays can have pixels that less than half the size at 200 PPI or higher

 

If, for example, a 1000 x 1000 pixel image is displayed at 100% (i.e. each pixel in the image is displayed using single pixels in the display) on a standard display it will be 10" x 10" on screen.

But, if the same image is displayed on a retina display at 100% it will only be 5" x 5". If the viewing distance isn't reduced (to take a "closer look" at the smaller image) the 5 x 5 inch version will appear 2x smaller and hence 2x sharper. You may also not be able to see single pixel defects in the image (CA fringe, dust etc.) as they appear 1/2 the size.

 

However, if the image is displayed at 200% on a retina display it returns to the same size it was displayed on the standard resolution screen. Alternatively the image can be inspected from half the distance, but that may lead to bad posture, neck and back ache!

 

Hope that helps.

 

Mark

Edited July 30, 2019 by M.Chapman

[sb photos]

1 hour ago, M.Chapman said:

 

A minor caveat, if you happen to be using one of those hi resolution 4K monitors (or above) or an Apple Retina display which has pixels so small you can't see them, you may need to inspect at 200%. To inspect your image at 100% it's important that you can (just about) see individual pixels in your image.

 

Mark

 

As 4K and 5K displays are becoming far more common in use, and will eventually dominate the market, I often wonder what what displays are currently used by picture desks and Alamy for QC?

[M.Chapman]

3 minutes ago, sb photos said:

 

As 4K and 5K displays are becoming far more common in use, and will eventually dominate the market, I often wonder what what displays are currently used by picture desks and Alamy for QC?

 

Indeed, perhaps Alamy will need to stipulate exactly what they mean by inspect at 100% in future? Does it mean viewing at 100% (1 image pixel displayed on 1 display pixel) on a display with 100PPI from a viewing distance of around 50cm. Maybe Alamy have already swapped to 200PPI displays and that's why there have been fewer QC fails of late? I haven't heard the screams from offenders being locked in clink for ages. It must be awful lonely in there these days. 

 

Mark

[Harry Harrison]

21 minutes ago, sb photos said:

As 4K and 5K displays are becoming far more common in use

As someone who doesn't use one, what is the advantage of having one? I appreciate that you can get more things on there at the same time, but apart from that?

 

Or is it in order to watch 4k, 5K 8K.. video?

[MDM]

1 hour ago, Harry Harrison said:

As someone who doesn't use one, what is the advantage of having one? I appreciate that you can get more things on there at the same time, but apart from that?

 

Or is it in order to watch 4k, 5K 8K.. video?

 

I don't think there is any advantage for stills photography at 27" or less as the pixel density is too high for comfortable viewing in my opinion. I guess there are advantages for video makers if they are shooting at those higher resolutions but not something I know anything much about at the moment. My son got one of the first 5K iMacs when they came out and I've had a few plays with it but I would take my 27" Eizo at 2560 pixels any day with or without a second monitor.

Edited July 29, 2019 by MDM

[Mr Standfast]

11 hours ago, MDM said:

First of all take this positively as it is certainly meant that way. As you are (reasonably) new to photography, if you find yourself asking very basic questions like this, then you should consider the possibility that you are trying to run before you can crawl so to speak. Learning the basics and having a solid grounding in photographic technique is very important if you are attempting to sell your pictures. You don't need to be professional to supply pictures to Alamy but you should be able to produce professional quality pictures. For those of us who catch the photography bug, the experience of learning is amazing and that learning should never end, no matter how long one has been doing it. There are so many people nowadays practising photography in one form or other and it is really worth getting the basics right if one wants to stand out from the crowd. While people here on the forum are very helpful, there are better places than here to learn the craft. Have a good trip 😀.

 

One of the best posts to a "reasonably new to photography" post I've seen.

 

Suzi, if your first experiences with Alamy QC are bumpy, don't let it put you off photography.

[suziq]

Thanks all!

 

[MDM]

 

 

 

29 minutes ago, Mr Standfast said:

 

One of the best posts to a "reasonably new to photography" post I've seen.

 

Suzi, if your first experiences with Alamy QC are bumpy, don't let it put you off photography.

 

Thank you 😀. 

 

Making mistakes is the best way to learn photography I think as long as you remember and don’t repeat them too often. So just dive in. 😎

[sb photos]

9 hours ago, MDM said:

 

I don't think there is any advantage for stills photography at 27" or less as the pixel density is too high for comfortable viewing in my opinion. I guess there are advantages for video makers if they are shooting at those higher resolutions but not something I know anything much about at the moment. My son got one of the first 5K iMacs when they came out and I've had a few plays with it but I would take my 27" Eizo at 2560 pixels any day with or without a second monitor.

 

The main advantage is to the manufacturer not the stills photographer, unless you also shoot 4K video. Like all industries, display manufacturers continuously push new technology to the masses to keep up sales revenue.

 

Personally I undertake photo editing at home on a Mid 2012 15" MacBook Pro (i7 quad core) 1TB SSD 16GB memory and the amazing AG hi-res display (1650 x 1050), but carry smaller and lighter options in my shoulder bag or back pack.

[Harry Harrison]

9 hours ago, MDM said:

I don't think there is any advantage for stills photography at 27" or less

 

Thanks, I suspected as much, but I suppose for those upgrading in the Apple universe there is no choice.

 

11 hours ago, sb photos said:

I often wonder what what displays are currently used by picture desks and Alamy for QC?

 

Good point.

[MDM]

46 minutes ago, Harry Harrison said:

 

Thanks, I suspected as much, but I suppose for those upgrading in the Apple universe there is no choice.

 

 

Good point.

 

Yes there is - use an external monitor as well if buying an iMac but iMacs are relatively limited in terms of upgrading. Or buy a MacPro - very expensive though. Apple have tended to neglect this market but have announced a new even more expensive one coming this autumn. With the continually plummeting £, the final cost is anyone's guess.

 

Right now following the latest developments: £1 = $1.22, €1.09

Edited July 30, 2019 by MDM

[Harry Harrison]

29 minutes ago, MDM said:

but iMacs are relatively limited in terms of upgrading

 

I'm psychologically preparing myself to replace the defunct hard drive in my old Imac, what a performance. Still I have to say that it's very nice when it's working though I don't use it for PP.

[geogphotos]

13 hours ago, M.Chapman said:

Hi Ian,

 

A typical (standard resolution) display has around 100 pixels per inch (PPI)

The latest 4K, 5K and retina displays can have pixels that less than half the size at 200 PPI or higher

 

If, for example, a 1000 x 1000 pixel image is displayed at 100% (i.e. each pixel in the image is displayed using single pixels in the display) on a standard display it will be 10" x 10" on screen.

But, if the same image is displayed on a retina display at 100% it will only be 5" x 5". If the viewing distance isn't reduced (to take a "closer look" at the smaller image) the 5 x 5 inch version will appear 2x smaller and hence 2x sharper. You may also not be able to see single pixel defects in the image (CA fringe, dust etc.) as they appear 1/2 the size.

 

However, if the image is displayed at 200% on a retina display it returns to the same size it was displayed on the standard resolution screen. Alternatively the image can be inspected from half the distance, but that may lead to bad posture, neck and back ache!

 

Hope that helps.

 

Mark

 

Thanks very much Mark. I would assume that a lot of people in the world of stock photography use Macs and this sort of display. It does make me wonder if those doing QC at Alamy and elsewhere are viewing at 100% rather than 200%. 

 

Thinking back to viewing slide scans at 100% and contrasting that with now and using 27inch Retina it makes it clear to me that judging sharpness of focus, noise etc is quite a subjective business.

[MDM]

15 minutes ago, Harry Harrison said:

 

I'm psychologically preparing myself to replace the defunct hard drive in my old Imac, what a performance. Still I have to say that it's very nice when it's working though I don't use it for PP.

 

External solid state drives running through USB3 connectors on the computer or Thunderbolt drives (desktop or mobile) can be extremely fast, negating the need to replace the internal drive but  will depend on the age of the machine as to their usability. In recent years Apple seem to have been moving towards making their machines not upgradeable which is a real shame.

[M.Chapman]

2 hours ago, geogphotos said:

 

Thanks very much Mark. I would assume that a lot of people in the world of stock photography use Macs and this sort of display. It does make me wonder if those doing QC at Alamy and elsewhere are viewing at 100% rather than 200%. 

 

100%? If so this could be a key reason why the number of QC fails reported on the forum seems to have dropped in recent times?

 

Mark

[sb photos]

2 hours ago, Harry Harrison said:

 

I'm psychologically preparing myself to replace the defunct hard drive in my old Imac, what a performance. Still I have to say that it's very nice when it's working though I don't use it for PP.

 

Harry, It's relatively easy replacing a hard drive or upgrading to an SSD internally in all iMacs, but I've replaced hundreds, working on Mac's since 1987. What iMac do you have?

[sb photos]

10 minutes ago, M.Chapman said:

 

100%? If so this could be a key reason why the number of QC fails reported on the forum seems to have dropped in recent times?

 

Mark

 

When viewing at 200% on  a MBPr 13" the image starts to pixelate.

[Harry Harrison]

2 hours ago, sb photos said:

Harry, It's relatively easy replacing a hard drive or upgrading to an SSD internally in all iMacs

 

Thanks Steve, that's very encouraging, I have watched the videos and practiced on our previous 'white' Imac (no longer required) so I can see that it should be within my capabilities and I have the tools though it's a little alarming how much surgery is required to get to it.

 

It's old so not worth going to an SSD really as we only use it for the internet in the kitchen, for which it is ideal. I bought a new 320GB hard drive plus a USB El Capitan boot drive (I just hadn't got around to making my own stupidly). It began dropping out to the '?' over a period of weeks then would only go to that. I can hear the hard drive trying to start a few times then giving up.

 

I do have a question though, if you don't mind. In its present state I can't get it to go to Startup Manager using the Option key on startup so cannot see the USB boot drive, I just get a white screen with the cursor, which I can move. If that still happens once the new drive is in then obviously I'm stuck.  I'm using a relatively old white plastic wired keyboard, not aluminium as I'm pretty sure you can't use the Bluetooth 'Magic' keyboard that we normally use. Any ideas would be gratefully received!

 

Oh, and it's an A1224 so that is pretty old of course, though I'm happy with El Capitan and all the browsers still work, unlike the 10.6 White Imac.

Edited July 30, 2019 by Harry Harrison