iMac Recommended Specs for Hobby Photgraphy

Get the largest hard drive you can afford, and stick with 8gb of RAM for now as the RAM in the current iMacs is very easy to replace on your own and much cheaper from places like www.crucial.com. I'm also a photographer and I just recently purchased the mid 2015 27" iMac 3.3ghz with 8gb of RAM and 2gb fusion hard drive.

 

It's hard to say what a "hobby" photographer is going to need. Some hobbyists get involved with rather complex post processing that can challenge the most powerful current iMac.

I just replaced the the machine that I use at work for graphics/image production. I replaced an ageing Early-2009 PowerMac with a new iMac. Since I regularly work with 36mp RAW images in Lr and images in Ps so large that the PSD format won't support them (I have to use the PSB "large document" format to support 48x96" 300ppi images with 1-2 smart objects each with 1-3 Filters and 5-15 other layers and file sizes from 5 to 12gb), I chose to go with a fully blown iMac 27" 5k with the i7, 32gb RAM, an a 1tb SSC. All of the image file live on external drives (10tb total for now, but another 8tb will go online this summer). The new machine is noticeably faster than the old PM (dual processor 8 core, 16gb RAM, 7200rpm HD).

If you work with massive files like I do at work (I work for an art photographer) then you need the RAM, the SSD, the i7 and a whole stack of external drives. For more modest print needs and for web resolution images a more basic i5 with 8gb should do perfectly well, and RAM can be upgraded later. You'll want either a larger than default fusion drive or, if you go with a SSD, expect to need an external drive for you image files at some point. At home, I work with a Windows 10 box with an i7, 7200rpm HD, and only 8gb RAM and have no issues with my personal Ps & Lr work, even with print sizes up to 13x19.

Future proofing is difficult and can be expensive. You might consider opting for the i7 since the processor can't be upgraded later, but for modest sized RAW files and even the highest resolution cell phone images the i5 should work fine.

 

I wont tell you what to get but perhaps some things to consider that may help you in your selection -

Storage - Consider 512gig SSD over Fusion. Later, add an external drive and perhaps put your photoshop/photo files on that drive.
This formula has distinct advantages. Also, if you use a single fast external drive, USB3 is as "fast" as Thunderbolt. The latter only has the advantage in multi-drive/RAID set up.

RAM - which ever route you go, just know that Photoshop LOVES RAM. Which ever path you take, focus on having a minimum of 16 gigs with 32 gigs ideal. While folks might say you can do with less, one often has Lightroom and Photoshop open along with other applications and how quickly RAM is used.

Additional thoughts -

Software - As you are a hobbyist, you may find Lightroom invaluable but require something "smaller" or less featured than Photoshop. You may want to investigate some alternatives. There are some pretty impressive apps out there that are not as full featured as Photoshop but certainly has the tools a hobbyist would find valuable.

Last - Screen calibration. For Macs, the "soft calibration" sometimes referred to as creating screen profiles should be considered for both consistency and striving towards getting as close to "accurate" as your screen can provide. There are tools for this but if you are not familiar with the notion, better to read up upon it and then explore options.

 

Wow! That blows my mind!

 

With respect to Photoshop, don't fret as much about the video card but more about the CPU. Though Photoshop (now) can take advantage of some goodness of better cards, in real world use, only a small part of Photoshop is impacted (some filters as example that run a tiny bit faster with certain GPUs).

 

As a hobbyist then it won't make too much difference to you, but modern apps will use the hyperthreading in the i7 more and more as time goes on. You may want to look at pixelmator or some other smaller apps to lightroom for your editing as well, they tend to be easier in resources and provide some excellent tool for the hobbyist at a low price.

As for ram the 27 inch is home upgradeable so a 16gb kit will give you 24gb more than enough for any photography editing at far less than Apple will charge.

 

I am also a hobbyist and will offer a different viewpoint:
Consider a MacBook. That will enable you to do editing on the road and still have a large monitor at home if needed. Buy the best model you can afford on your budget. Get at least 256k of SSD as photos eat up space quickly. Unless you are doing some really heavy duty editing any one will work just fine. I like Pixelmator because it is less expensive than PS and does everything I need. Also look into MacPhun's line of editing tools; things like Snapheal make it easier to delete unwanted background objects. There are several other similar programs out there as well.

Also, get backup storage. Keep two backups of all photos so if something goes wrong you don't lose the work. Cloud storage is nice but gets expensive especially if you have data caps. External storage also lets you off load pictures to conserve HD space.