FYI - I've added this as I was asked for examples of the Irix in action.
At
5 bedroom town house for sale in Broad Street, Alresford, Hampshire, SO24, a UK property portal, are examples of a shoot I recently made using the Irix 15mm inside (I used a 24-70 for the outside - except the front image which is not mine).The light was an issue on the day with rapid and frequent changes from sunny to dark, thundery clouds.
My experience of using the 15mm has been positive. It is small, in comparison with the 15-30, and is therefore easier to set-up in tight positions - very useful in smaller UK homes. The distortion is low and corrections are easily made. My client is not fond of exaggerated wide angle shots so cropping is the norm with the 15mm, however, when required, ie the wide angle kitchen shot, the 15mm captured the content nicely. I do wonder whether cropping in post is actually easier than composing on site. With tight timescales, especially with the vendor present, shooting is rapid, which means a more considered crop in post is perhaps more sensible. Also, and I think this is key, using a prime does make me see each room consistently, which is useful as I move quickly from room to room.
I accept there may be problems with extreme wide angles and achieving even flash illumination. These shots were mostly taken with 2 or 3 flashes hidden around the rooms on stands to get the light as even as possible.
3 properties shot now - the Irix 15mm is proving a very useful property lens on a K-1.