SoundHound wrote:
The Sigma 50mm F1.4's MTF drops off a cliff after a 15mm circle (about coveres a Canon APS H-1.275x sensor). Not such a good lens for FF.
SoundHound wrote:
The Sigma 50mm F1.4's MTF drops off a cliff after a 15mm circle (about coveres a Canon APS H-1.275x sensor). Not such a good lens for FF....
In my experience, its a fantastic lens on FF, even near the edges....
Note: While I do believe Sigma is going to sell several shedloads of these 85/1.4s, I will be sticking with the combo of Rokinon 85/1.4 + EF 85/1.8. The Rokinon covers 99% of my needs at 85mm because I far prefer manual focus and its drawing style (sharpness, bokeh, colour, etc.) is simply superb. When I (very rarely) need AF at 85mm, I can't think of a better lens than the 85/1.8. The Sigma would have to be really fast to beat the EF, and I doubt it will be. For many users though, the Sigma will offer a very nice all-in-one solution, IMO.
One other note about "rolloff" on the edges of MTF charts; I think more often than not this is due to field curvature. Unless the field is completely flat (rare) it is impossible to get an accurate MTF reading from a shot that is focused in the centre of the field on a flat surface (test chart). Now, some lenses have more field curvature than others, and sometimes even enough for it to be relevant in real-world applications, but it needs to be pretty extreme.
The wide-open edge/corner test results are entirely unflattering. Looking at the charts, one would conclude that the lens's edge performance at wide apertures is simply abysmal. It should basically look like a Coke bottle with readings like that.
In the real world, though, this is not the case. Here is the Rokinon 85/1.4 wide open on my 5D:
So, the results in the graphs and charts can only tell us so much. When the Rokinon is focused wide open in the centre of the frame on a flat surface, field curvature results in the edges not being focused on that surface. This is mostly relevant when shooting test charts. As the lens is stopped down, not only does it get sharper, but the DoF increases to the point where field curvature becomes much less relevant (despite the curvature of field, it is deep enough that the entire, flat test chart will remain in the field of focus).
Park Cameras in the UK is now taking pre-orders for the Sigma 85mm f1.4. I believe they are the first store to actually give a list price for this lens. The MSRP is £900.00, although there's a note which indicates that a competitive price is yet to be determined. All lenses sold at that store have a lower actual price than their MSRP.
Not sure how prices in the USA will compare to the UK. But if previous prices are any indication, a £900 MSRP in the UK will mean a USA street price somewhere near $900. If so, that'll be awfully close to a 135L.
stargazer78 wrote:
If so, that'll be awfully close to a 135L.
I'm not sure the price of the 135/2 L is relevant, considering that the Sigma is an 85/1.4 Aspherical. What is more relevant is the $2400 price of the EF 85/1.2 L. $1500 is a hell of a lot of money for 1/3 of a stop. The Canon also offers focus-by-wire and 1,025g of heft, but I'd hardly call those "features".
cogitech wrote:
I'm not sure the price of the 135/2 L is relevant, considering that the Sigma is an 85/1.4 Aspherical. What is more relevant is the $2400 price of the EF 85/1.2 L. $1500 is a hell of a lot of money for 1/3 of a stop. The Canon also offers focus-by-wire and 1,025g of heft, but I'd hardly call those "features".
I can't wait to see samples from the Sigma.
+1, I expect big rebate/prizecut if canon wants to move all competed items. Go Sigma, Samyang, Tammy, Nikon - let's keep our toys in low cost.
But if you're nitpicking, a 135 is definately not an 85.
One thing worries me with this sigma and the 50. And that's focus consistency. Since they have reverse-engineered the Canon AF code from what I've heard they don't focus as accurately as often as the canon versions do. And for me that would be a dealbreaker no matter how sharp they are.
MaxiKana wrote:
But if you're nitpicking, a 135 is definately not an 85.
One thing worries me with this sigma and the 50. And that's focus consistency. Since they have reverse-engineered the Canon AF code from what I've heard they don't focus as accurately as often as the canon versions do. And for me that would be a dealbreaker no matter how sharp they are.
People have had their issues with the 50, but these issues are generally resolvable by either having it calibrated or using micro-adjust.
cogitech wrote:
Also, the 85L AF is far from fantastic.
But it is more reliable and far more consistent (than the 50). My only issue with it is its speed. Even after I MA'd my Sigma 50 it still performed worse than my Canon 50/1.4 in terms of low light focusing within its working range (by that I mean within 20ft) and my Canon 50/1.4 isn't great at all in these conditions. I am very curious to see how the Sig 85 performs.
Since I was recently thinking about upgrading my 85/1.8, I'm glad to see there will be another alternative shortly.
However, as much as I like my 50, I'm kind of good having just that. If this is just an 85mm version, with the same kind of rendering, I probably wouldn't find that compelling. Will be interesting to see what makes this lens distinctive.
cogitech wrote:
People have had their issues with the 50, but these issues are generally resolvable by either having it calibrated or using micro-adjust.
.............
If only that were true, Paul. Sigma did not succeed in calibrating mine,
even though they had my 5D body to calibrate it to.
That said, I am keeping the lens and treating it like a manual focus lens.
It's plenty sharp and contrasty.
As the lens is stopped down, not only does it get sharper, but the DoF increases to the point where field curvature becomes much less relevant (despite the curvature of field, it is deep enough that the entire, flat test chart will remain in the field of focus).