January 2011 - Digital Group - Optimising For PCs

[spb]

An excellent start to the new year with 30 in attendance and lots of images to discuss.

CHANGING A PARTICULAR COLOUR

In response to a request from Vic Attfield, we spent a little time looking at how to change the colour of a specific part of an image eg an item of clothing. The official tool in Photoshop Elements is the Colour Replacement Tool. Pick the new colour in the Foreground Colour box and then brush over the area of concern. The place at which the mouse is first clicked and the associated Tolerance setting determine the range of colours to be replaced.

Personally I get better results by another method. Draw a rough selection slightly outside the area of interest eg using the Lasso Tool. Now open the Hue and Saturation palette, click on Master and select any other value eg Reds (it makes no different what you select so long as it’s not Master). Click on the offending item of clothing and choose a new colour using a combination of the Hue and Saturation sliders. I find this method much more controllable.

OPTIMISING YOUR PC FOR PHOTOSHOP

If your PC is not the latest and you work on large images with many layers, you may find yourself waiting for the PC rather a lot. Here are some things that you can do to to optimise the PC for Photoshop;

- add more memory (RAM). Check what you’ve already got by right-clicking My Computer and selecting Properties. Adding more RAM is the most cost-effective improvement that you can make but 32 bit operating systems cannot use more than 4GB. 64 bit operating systems can use more, depending upon the version – at least 8GB. However the only versions of Photoshop that can use more than 4GB are the 64 bit versions of CS4 or CS5.

- make sure that you have space on your hard disk (HDD). In My Computer, right-click on C: and select Properties. The pie chart will tell you what size disks you have and how full they are. I recommend that you have at least 10GB free. You may also have other disks or partitions which could be used to store your images. Check these also for use by the cache (see below). Ignore any small partition containing software loaded by the computer provider – this is for disaster recovery. If you need to free up space, Microsoft provide a Disk Cleanup utility with Windows which is worth running now and again, especially if you have had some software crashes as large temporary files can be left behind. If you need to add more space, HDDs have never been cheaper - £45 for 1TB is silly money.

- if buying a PC for Photoshop, any reasonably well specified desktop or laptop will do – aim for a multi-processor, at least 4GB RAM and 500GB HDD or bigger. Windows 7 64 bit Home Premium is a good choice (but check that any existing peripherals such as scanners or printers will be compatible by running the Windows 7 Upgrade Advisor on your old PC with these all switched on). You might also consider a Solid State Disk (SSD) for the C: drive which will start up Windows and Photoshop exceptionally quickly. This is relatively new technology and very expensive but get at least 60GB and also a large HDD for your data and non-critical programs. Don’t economise on the screen – it’s the window on your photos. If you have a laptop, consider connecting it to a good quality stand-alone screen which will always be better than the in-built one.

- if you have a 64 bit Operating System (OS) and Photoshop CS4 or CS5 you can choose to install the 32 bit or the 64 bit versions of Photoshop (or both) which come on the same disc. Normally you would install the 64 bit version but a reason to consider the 32 bit version is if you have a favourite filter or plug-in which is not 64 bit compatible. Photoshop Elements is only 32 bit – although there’s no problem installing this in a 64 bit OS. Photoshop is a well-behaved program and you can install as many different versions as you like on the same PC. You are permitted to install a particular version of Photoshop on two computers that you own but don’t forget to use Help>Deactivate before uninstalling from an old PC.

OPTIMISING PHOTOSHOP

Edit>Settings is the location for many Photoshop options. A few affect performance when editing;

- >Performance>Memory Usage should be in region of 70% to ensure that Photoshop has access to most of the RAM. Avoid running a lot of programs at the same time as Photoshop if the machine is struggling.

- >Performance>Scratch Disks (which is the additional working space apart from RAM). If you have a second partition or HDD with lots of free space, select this for the scratch disk rather than C:

- >Performance>History States – these are the number of backward steps available when editing images and they can use a lot of memory. Keep to the defaults (or less) for best performance.

In the bottom left hand corner of each image pane is the Status Bar. Click the triangle beside it to choose what is displayed. The Efficiency figure shows whether Photoshop has enough room in which to work. If it regularly dips below 90% you should implement some of the suggestions here.

OPTIMISING IMAGES

If your computer is struggling, there are some things that you can do to ease the burden;

- reduce the number of pixels in the image; an A3 print needs less than 8million at highest quality.

- reduce the number of layers, especially if they contain complete copies of the image.

- reduce the colour depth (CS). More than 8 bit colour is a luxury and many of the Photoshop tools won’t work.

I’m sorry if this month’s topic was a bit more technical than usual but we haven’t delved into this topic for a long time and I know many of our members struggle with the whole computing aspect of digital photography. Don’t hesitate to consult your local computer expert (not me) if you are having problems. We all get into difficulties sometimes and I have had good service from Alcom Computing in Chesham over several years.

NEXT MEETING

The next meeting of the digital group will be on Thursday 3rd February in the Small Barn Hall. Peter Jones has kindly agreed to officiate as I shall be up a mountain in Colorado struggling for oxygen.

Cheers, Steve Brabner

[peterjones]

Many thanks to SB as always for your time in preparing and presenting the digital evening.

For my sins I am deputising for Steve whilst he is busy globetrotting and I will attempt to follow a similar format to Steve.

Please bring any images you would like to discuss; if there aren't enough images I will bore you all with a couple of my latest AVs; in addition I will share with you two or three P/S processes including a demo on embedding a copyright symbol within your images.

I look forward to seeing you all the next next digital evening.

Peter.

[spb]

One further tip on optimising Photoshop - if you use Bridge (the image browser that comes with Photoshop CS), it stores image previews in a cache.

Linda Sharp recommended emptying this occasionally (Bridge>Edit>Preferences>Cache>Purge Cache) or you can set limits to the size and turn it off completely on the same screen (Keep 100% Previews In Cache). The only downside is that previews will take slightly longer to display.

Cheers, Steve.