Originally posted by UncleVanya Honestly the opposite. The thing to remember is that at any given focal length the Full Frame will show a much wider angle of view if the lens is a full frame lens as well. So an 18mm on APS is only as wide as a roughly 27-28mm on Full Frame. A 15mm on APS is about the same as a 22mm on Full Frame. Thus the 20mm Full Frame coverage of an FA 20-35 is quite wide - almost as wide as the 12mm coverage offered by the DA 12-24 (but not quite).
You're right, I tested this because I have a 24mm Pentax-A old lens and used to compare (roughly) with the DA 15mm. I dunno why I don't dig the 24mm out more and use, I guess the DA 15mm in all its silver coating glory just looks so good with the same silver coating KP makes me not want to split up that 'relationship'
I have a Sigma 10-20mm, and tbh I don't feel the need much with what I shoot to go past the 15mm FoV. So if I could get a FF lens that extends down to 24mm it probably is enough and will do the majority of landscape shoots.
Using that mentality means I'm seeking a 70-200mm (or equivilient FoV partner) for the KP/APS-C sensor.... which would lead to what suggestions I wonder?
Originally posted by clackers Bruce, I've got the Pentax FA J18-35 and FA20-35 as legacy lenses, the DA 12-24 (works from 17mm onward) and the Sigma DG12-24.
But if you've got pro aspirations, just go for the 15-30, I reckon.
Yes, it's a big boy's lens for a big boy's camera with a price tag to match. I'm sure you understand.
You may do everything you need with the 24-70 f2.8. Remember that's an angle of view at the wide end not much different from the DA15 on a cropped body.
I am not a big boy nor a rich boy clackers :'( Just, loan me the 18-35 and 20-35 already
Originally posted by SteveinSLC The 15-30 is very large. But the most common things I use it for are landscapes or astro, both of which are mostly done on a tripod, where the weight doesn't really matter. 15mm on FF is really wide...not typically a focal length you'd use for a walk-around street picture. The 28-105 is much better for that.
I have a K-70 as my back up/lighter weight option. For that I have a 15mm Limited and an 18-135. The two of those put together weigh less than the 15-30, so are a much better solution for hiking, backpacking or lightweight travel.
This was what I was thinking, perhaps less expense and weight and a more versatile approach.