27" iMac vs 27" iMac w/Retina display

Unless you are editing 4K video there is no point in it.

One of my friends is an apple fanboy and bought it, for programming and web browsing no one in the office, including him, could tell a difference between the 27" non-retina and the 27" retina. It only matters if you are working with ultra-high-resolution images/videos. That's why it is a 5K display, so you have room to edit your 4K video.

More than likely, every picture that you were shown was

a jpeg photo. Regardless of resolution, jpeg compression

removes a lot of detail in an image. You would most likely

see a difference with photos in a RAW format and even at

that, the would have to be a very high resolution.

Generally speaking, pixels are pixels. If a video is 1080p (or i),

it is 1920x1080 pixels. Blowing it up on higher resolution screen

will not reveal any more detail. The same goes with photos. The detail

revealed will depend on the total number of pixels in the image.

I haven't seen an iMac with a retina screen yet but earlier today I did see a MacBook Pro 13 inch with a retina screen in a shop. Compared to my MacBook Pro 13 inch (mid 2010, non retina) the difference is huge (at least to my eyes). There is no need to look at special pictures, just look at e.g. Finder windows and compare the resolution and gradation smoothness of those with the ones from a MacBook Pro non retina or MacBook Air. For the first time Yosemite finally started looking good to me (I never really found it particularly good looking but that is an other discussion). Two things to keep in mind I think. Individual eye sight plays a role, a friend of mine who is sixty something says he can't really see the difference between a retina iPad and a non retina iPad. And two, one may be further away from the screen of an iMac than the one from a laptop. When I look at the screen of my iMac 27 inch I don't really notice the fact it isn't retina as I am sitting at my desk and looking from a comfortable distance. When I look at the screen of my MacBook Pro (I always bend a bit over it) I definitely see the individual pixels and they annoy me after having spent some time on my iPad.

The differences I've noticed so far:

1. The Retina display is significantly brighter. While a standard display has decent contrast, the Retina is strikingly brighter. If you like higher contrast in your work, this is a good answer.

2. A Retina display is ideally suited for detailed video work, where high detail really matters. If that's your work, Retina is a real step forward.

3. For everyday use, like web browsing, a Retina display is unnecessary,

4. For viewing a movie, a Retina display is unnecessary. There's plenty of image in a typical film to be perfectly satisfactory.

5. The current iMac comes with a 27" display. This kind of on-screen real estate makes moving around files very easy; compare that to the kind of tricks needed if you have a laptop. This really improves your computing experience.

6. While specs vary between models, the features on a Retina iMac are very strong - as good as you'll find on an iMac. This means your machine will be usable for years to come.

I've used Macs for years, though I'm not very technically knowledgeable. I bought an Apple-refurbished retina iMac a couple of weeks ago and have been able to compare it with my late-2013 iMac 27" at work. Both are remarkable machines, but I like the retina better than I thought I would. I do a lot of word-processing and reading of documents on screen, both Word and PDF. (I don't do much video or image processing, so I wasn't sure whether I was overdoing it with retina) The most unexpected improvement is the clarity of on-screen print in both those programs and in browsers. I've noticed significantly less fatigue with the retina display, easier to keep going in the long term. I also like the speed of the 1TB fusion drive over the standard 1TB drive in my work iMac. Other observations:

-From a distance of about 3-5' plus, it's difficult to see any difference in picture clarity between the retina and the regular screen. Only at close distances does the clarity of the retina become apparent, and then only with higher resolution images. But at those distances-normal viewing distance-the difference is noticeable.

-I've been using dozens of images from interfacelift for rotating wallpaper on my work iMac. They look great on that 27" screen and I was concerned how the images I like that are only available in 2560x1440 would look on the retina screen. They look great still, though I'd say that the processing the retina machine does to accommodate the lower-resolution image to the higher resolution screen makes the image slightly less clear than on the native resolution iMac 27" screen. But that's only really apparent from closer than about 2-3 feet, and the difference isn't enough to dilute the experience. And there are a number of retina-grade images (5120x2880) on interfacelift and many more (hundreds, I'd say) 4K-resolution images (3840x2160) available on that site and others. I can't really see much difference, if any, between the 5K and 4K images on my retina screen at a normal viewing distance (i.e., from sitting at a keyboard).

-With the recent price decrease for the retina iMac, I wouldn't go back to the non-retina machine. And I'd recommend the refurbished route (at least those available from the Apple Store), where a late-2014 retina iMac with 3.5 Ghz processor, 8GB RAM, 2GB video RAM, and 1TB fusion drive is regularly available for $1949 delivered. That's only about $150 more than a new, non-retina 27" with 3.2 Ghz, 8GB RAM, 1GB video RAM, and 1TB non-fusion drive.