Fine Tuning lenses
Oct 16, 2015 13:48:00 #
Hi once again, I know there is many posts on here for Fine Tuning. Once again I find myself trying to fine tune a lens. Set the D750 and Sigma 105 2.8 up on tripod, Mirror up, using radio trigger and a focus chart set at about 10ft or so away at 45deg angle to camera, OS off and lowest App for lens. I take shots and preview them on the screen. Each shot I take gives a different reading, I tried over and over again, moving focus then re-shooting. The results are never constant, either spot on, back focus, or front focus, No wonder when I do close up portraits I dont always get them sharp. Remember this test is on a tripod so can be no user error . Any advice please as Nikon will not entertain a Sigma lens..Thank you in advance.
Oct 16, 2015 14:17:37 #
How stable is your tripod? Did you try to test other lenses? If you tried, did you have the same problem or not? If you had the same problem with all lenses problem your problem is not in lenses, maybe tripod, camera or users mistakes.
jimmix7 wrote:
Hi once again, I know there is many posts on here ... (show quote)
Oct 16, 2015 14:31:43 #
Tripod solid,, camera solid,, mirror up, radio trigger, How else can i keep it solid this is not camera blur, its off focus, each time is different, Thanks for the tips. Im gonna try all my lenses tomorrow but i think they are all the same.. Thank you
Oct 16, 2015 14:42:21 #
Does this happen when you manually focus the lens(es)? Sounds like it may be a camera problem...could the sensor be slightly loose?
Oct 16, 2015 14:56:11 #
jimmix7 wrote:
Hi once again, I know there is many posts on here ... (show quote)
Why not post a few of the shots with STORE ORIGINAL checked, that way people can see what you are talking about and possibly offer opinions/help based on what the focus points were?
Oct 16, 2015 15:20:26 #
I am sorry I did not ask you about your settings /shutter priority and focusing mode/.
jimmix7 wrote:
Tripod solid,, camera solid,, mirror up, radio trigger, How else can i keep it solid this is not camera blur, its off focus, each time is different, Thanks for the tips. Im gonna try all my lenses tomorrow but i think they are all the same.. Thank you
Oct 16, 2015 15:58:12 #
jimmix7 wrote:
Hi once again, I know there is many posts on here ... (show quote)
Use spot focus and focus on a definite point. Get your target closer, no more than 4 feet at 105mm, and shoot the lens wide open for the shallowest DOF. My favorite focus target is a yardstick laid at a 45 degree angle to the plane of the lens, makes it very easy to see the focus field.
Oct 17, 2015 03:05:30 #
Thanks for the advice, I will take some more test shots today, When I take a bunch of test shots and check them I usually delete them before testing again, I'm using spot metering and the reason I'm testing at 10ft approx is because I often shoot portraits at that approx distance, and I used 3.2 for some strange reason this lens does not always go to 2.8. (but it is a 2.8 lens).I have not tried this in Manual focus mode (as I am testing the Auto focus of the camera) but I will today. Like I say earlier I use a Focus Chart and once the camera is set up I change nothing, just the focus ring after each shot taken. The camera mode is set to 'M'. Thank you for all the feedback..
Oct 17, 2015 04:10:05 #
If "camera mode" means focusing mode your mistake is here. You should use "A" mode on camera and lens.. "M" mode is using for manual focusing.
jimmix7 wrote:
Thanks for the advice, I will take some more test ... (show quote)
Oct 17, 2015 04:25:44 #
MMC wrote:
:?: :?: :?: All this time I thought "A" was aperture and "M" was for manual, which would not effect AF.If "camera mode" means focusing mode your mistake is here. You should use "A" mode on camera and lens.. "M" mode is using for manual focusing.
What did I miss? :|
Oct 17, 2015 04:56:13 #
This picture shows A /green arrow/ stands for autofocus and another A /red arrow/for Apperture.
Flyextreme wrote:
:?: :?: :?: All this time I thought "A" was aperture and "M" was for manual, which would not effect AF.
What did I miss? :|
What did I miss? :|
Oct 17, 2015 05:48:03 #
jimmix7 wrote:
Tripod solid,, camera solid,, mirror up, radio trigger, How else can i keep it solid this is not camera blur, its off focus, each time is different, Thanks for the tips. Im gonna try all my lenses tomorrow but i think they are all the same.. Thank you
I have never had much success calibrating a 300mm 2.8 Sigma lens before I ungraded to the Nikon version. Wasn't unhappy with the focus just wanted to see if it could be better.
Results varied so I left it at the default value. Suspect the auto focus has some variation.
Oct 17, 2015 05:48:26 #
Flyextreme wrote:
:?: :?: :?: All this time I thought "A" was aperture and "M" was for manual, which would not effect AF.
What did I miss? :|
What did I miss? :|
Yes I agree. Camera is set to 'M' on mode dial. Lens and camera set to AUTO focus. I have moved in on focus chart to 5ft. When zooming in on back screen the focus is shifting back and forward, I have also noticed the image may move very slightly from one shot to the other and there is no movement at all on the camera and 'OS' is off !!, I am going to forward a latest findings soon..I'm not sure to crop in or not in the images..
Oct 17, 2015 06:12:51 #
MMC wrote:
At least I can see were the confusion was. Not just "A" or "M" but "M/A-M", "A" and "AF".This picture shows A /green arrow/ stands for autofocus and another A /red arrow/for Apperture.
Oct 17, 2015 06:16:57 #
Are you sure that your camera finished focusing when you pressed release button or used your remote. To make sure set your camera a1 and a2 Focus for this test and your camera would not take a picture if it is not focused.
jimmix7 wrote:
Yes I agree. Camera is set to 'M' on mode dial. Lens and camera set to AUTO focus. I have moved in on focus chart to 5ft. When zooming in on back screen the focus is shifting back and forward, I have also noticed the image may move very slightly from one shot to the other and there is no movement at all on the camera and 'OS' is off !!, I am going to forward a latest findings soon..I'm not sure to crop in or not in the images..
If you want to reply, then register here. Registration is free and your account is created instantly, so you can post right away.