All the examples done in AV mode. body is 350D. ROOM @this one with flash. TOYS OUTDOOR this one at 24mm ------------ what do you guys think? in the ROOM test, the f2.8 seems washed out. contrast is appalling. in the TOY test. f2.8 has dimmer background. same goes to the OUTDOOR test. contrast seems to be closer.
You cannot compare it using matrix metering and aperture priority, it's letting the camera decide the exposure for you which is probably the cause of it, but since we are testing your lens. Set it at manual one at Exposure 1/250 Aperture: f/2.8 ISO equiv: 1600 the other Exposure 1/125 Aperture: f/4.0 ISO equiv: 1600 and fix the WB also
yes. WB is fixed all the while. I'll try out your suggestion (which is by far the best I've come by) anyway I've tested AV mode with my 50mm f1.8 and here's how it looks. looks fine. anyway I just tested the stuff using manual mode, still dimmer on f2.8. however earlier (after posting this thread) I've done other tests and seems like exposure was fine on the 24mm side.
sorry Adrian, missed your response. which example? anyway they were all using constant ISO and WB. since it's AV mode, only aperture and the corresponding aperture. anyway latest tests shows that the exposure between f2.8 and f4.0 are same on other zoom range like 52mm and 24mm. it's just at 70mm it shows the brightness difference.
Hmmmn guess maybe is the long extension might have reduce the light comming. Got anyway of getting second copy of the lens?
no idea how to get 2nd copy of the lens, unless i bring to Sigma disti. tried manual mode, also outcome same. i was expecting the exposure for f2.8@70mm to be same as f4.0@70mm. as of now exposure between f2.8 and f4.0@52mm are same f2.8 and f4.0@24mm are same want to say body problem also cannot. want to say lens problem, also cannot. the thing is this lens extends as it goes wide (24mm). so yeah, you turn the zoom barrel to go wide. weird lens, but definitely nice at f4.0. since it still has 10 months warranty, I'm not making a fuss out of it yet. after all, f4.0 is nice.
Hmm.. The way I see it, Falcone's method should work best to see if f/2.8 has a problem. Both pictures should have the same exposure.
I too would force it in manual mode. Rather odd that 2.8 looks darker than 4 if all else is held constant. Can you try another body too?
i tested with manual mode already. still turns out like that. only dims at @70mm i would've done that if i have. i should be able to do that within the week or 2. --------- Now, I've tested Falcone's suggestion Exposure 1/250 Aperture: f/2.8 ISO equiv: 1600 Exposure 1/125 Aperture: f/4.0 ISO equiv: 1600 Now I've tested the above settings @70mm, seems that the Exposure level indicator shows that the f2.8 settings is 1 level lower than at f4.0. it's like if the f4.0 was at -1/3, then the f2.8 was like -2/3 (yes, tested it again. it sorta moves. staying around -2/3 most of the time. yes. target same spot) I tested the above again, this time @24mm, this time the exposure level indicator is the same for both f2.8 and f4.0 what do you guys think? faulty lens?
It simply shows this lens is not particularly good at wide open. Most lenses will show lack of contrast at wide open.
yeah. i tested 50mm f1.8 again, same method as the above. exposure level indicator remains same f2.8 and f4.0 as well. at first i thought it could be aperture blade issue but if it was then the fact that exposure remains constant at wider angles already disproves the thought.
Sometimes, the aperture blade might not move correctly. But it shouldn't happen at wide open, because the aperture blade only closes when you use smaller aperture. Try something like F4 and F8 see if you get the same inconsistent exposure. If it doesn't, then it's simply because the lens' sweet spot is not at F2.8
yup. regardless of the zoom distance, the aperture closes the same way. f2.8 is f2.8. now based on test, f2.8 works fine at other zoom range, exposure results same as f4.0 and / or higher. so i think we can conclude that the aperture blades work fine at f2.8, it's just that the lens doesn't capture light too well when f2.8@70mm. please do correct me if I'm wrong. anyway from what i see, the "problem" is easily fixed by upping the exposure by 1/3.
so far only 1 composition causes the contrast to appear. the rest like the toys and outdoor seem fine. i have no idea how to re-create the contrast issue. in that composition f2.8@70mm - washed out f4.0@70mm - fine f2.8@24mm - fine f4.0@24mm - fine contrast issue aside, yeah it works fine by just upping exposure by 1/3.
It's just the lens performance at 2.8. I believe the glass of that lens isn't that big right? Quite compact lens in comparison to the canon's equivalent. That's why I'm still collecting money for the Nikkor one instead. Hehe The only way is for you to compensate via post processing and only use 2.8 when you really need it.
Well, upping the exposure should reduce the shutter speed, so it's not a workaround without any consequences. Better than increasing ISO though.
PP can't help the contrast issue. well, it shouldn't be in the first place. color then no choice la. the Nikkor version $$$ oh. my friend bought a Nikkor 24-70 f2.8 ...... phew....... nearly can buy the EF 70-200 F2.8 L IS USM already. 82mm yes but size still a little smaller than it's non-3rd party counter parts. well yeah, workaround with consequences. the thing I'm more concerned about is the constrast issue. I have so far encountered 2 instances where it happens. so i just send it for warranty.
