Search results for 'back focus' - page 2111
Dead Pentax-DA 55-300mm f/4-5.8 ED
It's the key-way that engages the camera body with the lens focus mechanism. If you look at the rear of the lens, and hold it so the row of gold coloured contacts are at the top, you'll see the key-way at roughly 3 o'clock. Very different to all the x-head screws attaching the mount to the lens b...
Posted by JohnX on 17/04/2014 - 17:17
Dead Pentax-DA 55-300mm f/4-5.8 ED
Oh calamity.... The good lady in my life has managed to completely seize up the 55-300 I gave her, Can't focus, can't shift the zoom either, so I guess a trip to Johnsons is the order of the day...... Did the same to my 16-45, which was freed-up by a trip to Johnson's at a cost of less than £40 (in...
Posted by pgweber on 17/04/2014 - 17:31
Lens shake?
I was tempted to suggest it might be diffraction, but I doubt it is because at these speeds, the aperture is probably wide open - which in itself is never going to give best results. It might help to know what your aperture setting is and as Nigel has suggested, the crop magnifications. Also a...
Posted by ronniemac on 21/04/2014 - 19:24
Lens shake?
Well, I've been back to the rocks and tried again without the filter and this is the result: ISO 160 800th sec @ f7.1 @120mm I tried other subjects and it only seems to affect edges against white (or nearly white) backgrounds and seems worse on slightly out of focus edges Otherwise ...
Posted by michaelblue on 23/04/2014 - 14:39
Lens shake?
The problem seems to be in the out of focus plane. The rock in the top left hand corner that is in the focus plane does not exhibit the issue. Was the image from a processed RAW file or jpeg straight from the camera? I've always kept a filter on my 55-300 and never experienced any issue. No inte...
Posted by JAK on 23/04/2014 - 17:33
Lens shake?
Took this hand held with a 55-300mm @190mm 1/1250s f/4.5 iso 100. Have only resized to 72ppi for forum. Can't see anything as bad as you have. Similar subject Stan, but completely different shooting conditions/lighting. I think that the OP is seeing some chromatic aberration in the out of focus p...
Posted by Mannesty on 23/04/2014 - 17:53
Lens shake?
I have the full image. I've shown the worst affected areas, cropped only, no other processing, and included the full image. What else would you like to see? Take a look at the hole in the rock in the cropped image, it shows a definite green tint on about half its circumference and magenta on the ...
Posted by kh1234567890 on 24/04/2014 - 11:50
Lens shake?
I've tried all the lens correction tools in first Lightroom then Photoshop CS6 but nothing will shift this grey fringing. Chromatic aberration and colour fringing don't bother me as they can be fixed easily but this strange 'grey thing' is rather puzzling. I realise this is a heavy crop and most s...
Posted by michaelblue on 24/04/2014 - 14:31
K3 focus issues most confusing
I am having a very low success rate in getting K3 + DA*300 images in focus compared to my K30. Probably only 40% in focus. But worse still I can't see why. Take this butterfly shot. It is at 1/4000th sec. I know the DOF is very shallow but it confirmed focus on centre spot on the butterfly's head. I...
Posted by dcweather on 21/04/2014 - 20:31
K3 focus issues most confusing
What is your aperture set at?
Posted by ronniemac on 21/04/2014 - 20:34
K3 focus issues most confusing
In this shot it is F4. By the way, before anyone says - I wouldn't normally be taking butterflies that wide open! It doesn't alter the fact that the wings are blurred but the petals behind and grass in front are sharper.
Posted by dcweather on 21/04/2014 - 20:37
K3 focus issues most confusing
Have you calibrated to AF of the DA*300 to the K-3, using the AF Fine Adjustment Dave? If not, this would be the first thing I would do. I have to calibrate all my lenses with each camera, the longer the lens the more critical this becomes. As an aside, I've found the focussing on my K-3 to b...
Posted by davidstorm on 21/04/2014 - 20:41
K3 focus issues most confusing
Doesn't help I know, but this has been reported elsewhere, affecting a low number of bodies. Only remedy seems to be change the body, although one tog reported 'success' with a global +10 setting in AF Adjustment; odd though, as I would have thought all his shots would be oof?
Posted by JohnX on 21/04/2014 - 20:42
K3 focus issues most confusing
Additionally Dave, I would get your K-3 checked if I were you. It could have some mis-alignment of the mount or sensor - this would possibly create the effect you are seeing. If the alignment of the sensor is not parallel, the there will be a difference in the focal plane across the frame of the i...
Posted by davidstorm on 21/04/2014 - 20:45
K3 focus issues most confusing
It is evident that subject matter behind and in front of the butterfly are in focus. I'm sure you've done this, but if not, check your lens for grease marks or blemishes on the sensor. At these shutter speeds, I would be surprised if the problem is subject movement.
Posted by ronniemac on 21/04/2014 - 20:45
K3 focus issues most confusing
Another thought Dave, try taking some images of a page of small text at an angle, this would clearly show if there are areas of the images not consistently in focus across the frame and any differences in front/back focus. Ronnimac's suggestion above is a good one - if there is any smearing of anyt...
Posted by davidstorm on 21/04/2014 - 20:58
K3 focus issues most confusing
Thanks for all of the suggestions. I have calibrated my lenses but I think the DA*300 has reverted back to 0, perhaps when I upgraded the firmware. I'm not sure many of the above could cause front and back focusing at the same time, plus perfect images sometimes, but I will try them ! Dave
Posted by dcweather on 21/04/2014 - 21:15
K3 focus issues most confusing
Checked - definitely nothing on the lens or sensors. Read that link on the other forum and it does sound a bit like my problem. I just keep looking at that pic and thinking - How can the front stuff be in focus but the back antenna be sharper than the front but the wings be so soft? What if the len...
Posted by dcweather on 21/04/2014 - 21:34
K3 focus issues most confusing
What if the lens was right at its minimum focus distance. Could it be focusing on the back antenna which is far enough away to just be on the minimum and the leaves at the front because they are actually off at angle so further and back within the minimal focus distance? I was pretty close to the su...
Posted by davidstorm on 21/04/2014 - 22:08
K3 focus issues most confusing
I think that was it! Panic over. CAn't think of a better explanation. This one taken in same spot today with perhaps more thought and time:-
Posted by dcweather on 24/04/2014 - 18:36
