p.2 #1 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
mfurman wrote:
Have you seen the test pictures taken with 85 f/1.8 lens? Why would I want to change calibration of the camera when it works well with this lens? Should I have a different camera for every lens?
p.2 #2 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
J.D.: Not at all. That lens doesn't need calibration.
You mentioned lens/camera calibration.
I do not see any problem with my camera and other lenses (so the camera is fine).
Canon always requests both the lens and the camra for calibration. I just want to get a lens that is as good as my current ones.
p.2 #3 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
Like I mentioned - I tested 2 copies on 3 different bodies - always the same backfocus when autofocusing.
My feeling (and it's hard to test of course) is that this lens always backfocuses at anything close to 200mm and >f6 or something but you only really see it at mfd.
When your are autofocusing at like 10 meteres plus at 200mm it just looks a bit soft.
I agree with the autofocus findings from photozone - if you focus manually it's as sharp as a razor.
They should really have put that information on photozone about manual focus - that was the article that swung the sale for me...
I am returning my 2nd copy back to the shop tomorrow - not satisfied.
p.2 #4 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
Okay, perhaps I should explain a little more clearly.
Camera sensors are slightly soft to avoid a harsh, over sharpened look. Some come out of the factory sharper than others but they all meet some sort of tolerance limit. If your camera/lens combination meets your requirements then you don't need to do anything about it but sometimes it doesn't work out that way.
Canon would request your camera so that they can calibrate the lens to suit your individual camera, not necessarily to change anything in the camera itself. The camera might focus forward or backward or say in your case, it might be neutral. The lens, on the other hand, is a different component and will also have left the factory having met its own tolerance limits which may be different. You can simply tell your service agent to calibrate the lens if all the other lenses focus well.
p.2 #5 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
BTW: while I would not argue that your 85mm lens needs to be calibrated, on my monitor it does show a small amount of purple fringing in the wood grain at the top of the wider shot. But I don't know if that's the lens or the sensor or my monitor.
p.2 #8 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
Thank you for the picture. I think that the focusing distance is much longer than MFD though.
Have you seen my flower pictures taken with 85 f/1.8. That is what detail resolution, I am looking for. According to Photozone tests, 70-200 f/4.0 L IS should be better than 85 f/1.8
p.2 #9 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
J.D. said: ...on my monitor it does show a small amount of purple fringing in the wood grain at the top of the wider shot.
I agree, the lens is not perfect but I am still in search for equally sharp tele lens (with short focusing distance). Even 135 f/2.0 L, I tested, was not much better at f/2.2
p.2 #11 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
CA is nothing to do with calibration as far as I know, the 85mm does have a lot wide open but that is its only fault wide open and that is very good.
Jul 09, 2007 at 11:28 AM
Steve Spencer Offline • • • • • • • Upload & Sell: On
p.2 #12 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
mfurman wrote:
Have you seen my flower pictures taken with 85 f/1.8. That is what detail resolution, I am looking for. According to Photozone tests, 70-200 f/4.0 L IS should be better than 85 f/1.8
Hi Michael,
I think you are over interpretting the photozone tests. First the difference between the 85mm at f/2.2 and the 70-200mm f/4L IS is not huge in the test. The 85mm at about 1900 LW/PH and the 70-200 at about 2000 LW/PH in the center which is all that really matters for the pictures in question. Both are well in the excellent range and given that almost all measures fail to differentiate well at the extreme ranges of performance there is little reason to expect the 70-200mm f/4L to outperform the 85mm. Both should be good, however, and it is a puzzle why the 70-200 f/4L isn't doing that well. As others in this thread have suggested it appears that a likely answer is the smaller DOF for the 70/200 at 200 and f/4 than the 85mm at f/2.2. In my view trying to take photos of flowers with such a smaller DOF is extremely difficult and that is most likely the problem. I hope this helps.
p.2 #15 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
I got my new copy of the lens and it behaves exactly like the previous ones tested. It is not a copy-to-copy variation but the characteristics of the lens. I do not think, it is a focusing issue either (I may post some pictures later if there is some interest).
My (preliminary) conclusion:
1. The lens is very(!) good at 135 mm and f/4.0 (regardless of focusing distance) and may exceed prime sharpness at f/5.6 !
2. It is fine at 70 and 100 mm as well
3. At 200 mm, it is sharp at long focusing distances (actually better than at 135 mm) already at f/4.0. At focusing distances close to MFD (less than 5-6 feet for sure), it is unusable for me at f/4.0 and could be probably acceptable to some at f/5.6. As I said, it is not focusing issue, I think, but residual aspherical aberration.
This lens is probably better than the one, I tested before but it is not good at 200 mm and MFD.
p.2 #16 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
I too am waiting for a second copy. The main problem I found with the initial copy was luminance hazing in shadow areas, which was not present in my non-IS 70-200 f/4. Also not entirely satisfied about focus accuracy, which would anyway have resulted in a trip to Canon service for calibration. I have my fingers crossed that the replacement will more closely justify all the raves. Scary to think that all the duds might be in a round robin from user to user til the music stops.
p.2 #17 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
I just found some flower type shots taken with the mkIII at 200mm f4 and I see what you're talking about. It does get a bit soft when you're up close (comparing to the same type shot with the lens at 135mm which appears much sharper)
p.2 #19 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
mfurman wrote:
I got my new copy of the lens and it behaves exactly like the previous ones tested. It is not a copy-to-copy variation but the characteristics of the lens. I do not think, it is a focusing issue either (I may post some pictures later if there is some interest).
My (preliminary) conclusion:
1. The lens is very(!) good at 135 mm and f/4.0 (regardless of focusing distance) and may exceed prime sharpness at f/5.6 !
2. It is fine at 70 and 100 mm as well
3. At 200 mm, it is sharp at long focusing distances (actually better than at 135 mm) already at f/4.0. At focusing distances close to MFD (less than 5-6 feet for sure), it is unusable for me at f/4.0 and could be probably acceptable to some at f/5.6. As I said, it is not focusing issue, I think, but residual aspherical aberration.
This lens is probably better than the one, I tested before but it is not good at 200 mm and MFD....Show more →
I didn't read every post in this thread. However I think your expectations are unrealistic comparing a zoom of any sort thinking it should be as sharp as your 85. I don't mean that a bit sarcastically. I have tested more than a hundred lenses over the years the old way with the USAF resolution charts and film. A 200mm of any kind is hardly ever as sharp as an 85 of any kind especially a zoom, and I own a 70-200 F4 IS. There is almost always residual CA that sets in over 150mm that spreads the image. Also the 85 is a gauss derivative, more like a standard lens which is almost symmetrical internally with far fewer elements than any zoom. If you want maximum sharpness for your flower shots a zoom just isn't in the cards IMHO, get a macro, I wouldn't fight it. There are other reasons why the 85 is showing up better. The shutter speeds are higher at 2.2 than F4 besides being stopped down partially as compared to wide open, the tripod used becomes more important with a long lens. Also, your camera body focuses more acurately with an f 1.8 lens as compared to an F4. just my .02. The zoom may be sharp enough for many but a macro is better everytime.
p.2 #20 · EF 70-200 f/4.0 L IS - sharpness question - IS problem?
geniousc: Also, your camera body focuses more acurately with an f 1.8 lens as compared to an F4. just my .02.
I just wanted to say (again) that 70-200 f/4.0 L IS is absolutely outstanding (for a zoom) at 135 mm (even at MFD). I got shots (especially with my recent copy) that I almost sharper than 85 f/1.8 can deliver. The problems with sharpness (at MFD) start at > 170 mm.
This is not focus issue, I think (I usually shoot at least 30 shots for one setting, refocusing every time)
