Search results for 'back focus' - page 1745
Lens calibration - Focus Tune software
This was my test with the DFA 100mm f2.8 macro on the K-5: I focussed on the line 'However Nurse Todd' but the image would lead you to believe it was three lines up from that as it was back focussing. John K The actual focus point might not coincide exactly with the red crosss :shock: So it's...
Posted by Algernon on 28/04/2013 - 09:50
Lens calibration - Focus Tune software
This all makes me think the the sooner all DSLR's go mirrorless, the better. Surely the inaccuracy of the actual point of focus is down to the mechanical tolerances of the mirror adjustment and placement of the focus sensors. So with no mirror and the focusing being done by the image sensor sh...
Posted by Mannesty on 28/04/2013 - 10:00
Lens calibration - Focus Tune software
I focussed on the 'H' in 'However'. In pic 1 that clearly is out of focus, in pic 2 it looks good to me. I normally focus and recompose but in those kept the 'H' in the centre. The actual focus point might not coincide exactly with the red crosss :shock: So it's possible that you are focusing ...
Posted by JAK on 28/04/2013 - 10:10
Lens calibration - Focus Tune software
Not camera specific as far as I can see. If you read half a book do you then know the true ending :?: Some books aren't worth the effort. John K
Posted by JAK on 28/04/2013 - 10:12
Lens calibration - Focus Tune software
I often use a Brita refil box with a piece of black electrical tape on it to focus. Since this picture I've also stuck a vertical piece on. It's quite easy to see if the focus is correct what are actually print dots appear as 45 deg lines (even though they are dots :shock: ) I've also d...
Posted by Algernon on 28/04/2013 - 10:39
Lens calibration - Focus Tune software
Not camera specific as far as I can see. If you read half a book do you then know the true ending :?: Some books aren't worth the effort. John K :roll: :D
Posted by McBrian on 28/04/2013 - 18:11
Lens calibration - Focus Tune software
IMO this software is a complete waste of money and time.
Posted by Smeggypants on 28/04/2013 - 20:51
Lens calibration - Focus Tune software
This all makes me think the the sooner all DSLR's go mirrorless, the better. Surely the inaccuracy of the actual point of focus is down to the mechanical tolerances of the mirror adjustment and placement of the focus sensors. So with no mirror and the focusing being done by the image sensor sh...
Posted by Smeggypants on 28/04/2013 - 20:56
Lens calibration - Focus Tune software
Is the software camera specific? No, but some Canon and Nikon cameras output their adjustment settings, Pentax doesn't, which means you can only use the shot by shot comparison analysis method. It does produce interesting results though. I spent some time testing/adjusting some of my lenses to...
Posted by Mannesty on 28/04/2013 - 22:27
Lens calibration - Focus Tune software
No, but some Canon and Nikon cameras output their adjustment settings, Pentax doesn't, which means you can only use the shot by shot comparison analysis method. It does sound like a lot of work. Well I won't be trying it but don't let me stop anyone who wants to. You'd still need to check the res...
Posted by JAK on 28/04/2013 - 22:37
Lens calibration - Focus Tune software
Am I missing something or doing something wrong? Earlier I was testing my K30 with 18-55 WR kit lens - it seemed to focus ok at 0 but when I adjusted the fine focus to -10 & +10 it didn't seem to make much difference. Maybe it's only noticeable on sharper lens??:o
Posted by jemx99 on 28/04/2013 - 22:43
Lens calibration - Focus Tune software
Were you using the lens wide open? If not depth of field could hide the differences. You also say 'it didn't seem to make much difference'. That's all it is, a fine adjustment! John K
Posted by JAK on 28/04/2013 - 22:49
Lens calibration - Focus Tune software
Am I missing something or doing something wrong? Earlier I was testing my K30 with 18-55 WE kit lens - it seemed to focus ok at 0 but when I adjusted the fine focus to -10 & +10 it didn't seem to make much difference. Maybe it's only noticeable on sharper lens??:o It's more noticeable on faster lens...
Posted by Mannesty on 28/04/2013 - 22:58
Lens calibration - Focus Tune software
Yes I had the lens wide open and zoomed right in to view the test shots but didn't notice much difference - like you say John it is only fine adjustment but I thought I would have seen more of a difference.
Posted by jemx99 on 28/04/2013 - 22:58
Lens calibration - Focus Tune software
Yes Peter I suppose f3.5 isn't really wide enough.
Posted by jemx99 on 28/04/2013 - 23:00
Lens calibration - Focus Tune software
Pic one looks spot on to me, Nurse Todd is not in the center of the image, did you focus then recompose or change the focus point away from the center area to one of the outlying ones? if so you have intoduced an error in to your calculations. Agree with this. The framing, and hence the centre posi...
Posted by johnriley on 28/04/2013 - 23:04
Lens calibration - Focus Tune software
Focus point was the letter 'H' in the word 'However' John K
Posted by JAK on 28/04/2013 - 23:07
Lens calibration - Focus Tune software
In any event, the letter H has itself got depth, so it's not a line to mark a point. Brian's point is that the camera has moved between exposures, so the centre point, which is preumably where you have focused, has changed. In both images the centre point is sharpest but the piece of text is diff...
Posted by johnriley on 28/04/2013 - 23:12
Lens calibration - Focus Tune software
This was my test with the DFA 100mm f2.8 macro on the K-5: I focussed on the line 'However Nurse Todd' but the image would lead you to believe it was three lines up from that as it was back focussing. After dialling in a +4 adjustment I got this: Which is what I should have got the fi...
Posted by Smeggypants on 28/04/2013 - 23:13
Lens calibration - Focus Tune software
They were just two of a number of real world hand held shots taken over 10 minutes or so because I suspected back focusing. On others in between I dialled it in the wrong way and made it worse! It appears cured now. Double checked the adjustment with a wordsearch on the back of a cornflake packet...
Posted by JAK on 28/04/2013 - 23:17
