Search results for 'back focus' - page 1656
Completely Dejected (auto focus K5)
I think anyone that is saying they can sharp focus in manual is probably using a larger depth of field and therefore a large margin of error. I cannot see how it is possible to manual focus otherwise. Nonsense. Probably 80% of my lenses are manual focus only and I use them all the time with no prob...
Posted by womble on 30/12/2011 - 11:14
Completely Dejected (auto focus K5)
I'm surprised that after all previous discussions about MF nobody seems to understand anything about it :shock: :lol: Most modern screens and all Pentax screens are made for slow lenses and regardless of what lens you put on the camera, you only see the equivalent of f/2.4. Only Canon make a scre...
Posted by Algernon on 30/12/2011 - 11:39
Completely Dejected (auto focus K5)
Womble, if you have no trouble manual focusing then why did you fit a Katzeye screen?
Posted by Daydreamjay on 30/12/2011 - 13:15
Completely Dejected (auto focus K5)
You said that it isn't possible to manual focus at wide apertures... K was just saying that it is possible, although easier with a split screen. For me, I find it very hard to MF using the standard focussing screen. I resort to LV or my patented 'somewhere in the middle' technique. (I slowly and ...
Posted by Pentaxophile on 30/12/2011 - 13:47
Completely Dejected (auto focus K5)
Most modern screens and all Pentax screens are made for slow lenses and regardless of what lens you put on the camera, you only see the equivalent of f/2.4. Only Canon make a screen for use with fast lenses of f/1.2 etc. That doesn't prevent you from using them: K20D + A 50mm f/1.2 I us...
Posted by johnwhit on 30/12/2011 - 14:47
Completely Dejected (auto focus K5)
I what Algernon says is true then it is impossible is it not? If I shoot a portrait from a metre or so away and want the iris sharp I have a margin of error of 2cms. I am saying that without luck you're not going to nail it consistently without a focusing aid. I would live to be wrong! It wou...
Posted by Daydreamjay on 30/12/2011 - 14:55
Completely Dejected (auto focus K5)
If you get a rail similar to the one in the link I posted previously http://www.slrgear.com/articles/focus/focus.htm allowing back and forth movement of about 300mm each way and take several shots say 20mm apart.... one of them should be in focus.... if you set the focus at mid-rail first.... Ha! Ha...
Posted by Algernon on 30/12/2011 - 17:07
Completely Dejected (auto focus K5)
If you get a rail similar to the one in the link I posted previously http://www.slrgear.com/articles/focus/focus.htm allowing back and forth movement of about 300mm each way and take several shots say 20mm apart.... one of them should be in focus.... if you set the focus at mid-rail first.... Ha! Ha...
Posted by Pentaxophile on 30/12/2011 - 17:17
Completely Dejected (auto focus K5)
Womble, if you have no trouble manual focusing then why did you fit a Katzeye screen? What is the point of that question? Skill is skill and has to be recognised as such. Tools that are used to help make that task easier are available. Best regards
Posted by K10D on 30/12/2011 - 18:18
Completely Dejected (auto focus K5)
The one thing that hasn't been mentioned is practice. Manually focusing well needs lots of practice to gain the skill to judge the correct point of focus. It will be considerably slower than using AF and the amount of error can be surprisingly large. I have a magazine article on this somewhere in...
Posted by johnriley on 30/12/2011 - 18:44
Completely Dejected (auto focus K5)
I've just done some more tests, all shot at 1.4, tripod with remote. The lens was the Pentax FA 50mm This one was EV 0.3 so pretty dim, not expecting much here, Auto Focus (single point on the large letter T of the word "The" on the left of the page.) This one was the same as above but Li...
Posted by Daydreamjay on 30/12/2011 - 19:21
Completely Dejected (auto focus K5)
That last test was rough-and-ready but more meaningful. For more usual apertures the DOF would mean focus was close enough, but for precision focusing you'll need more light by the look of things. Your manual focusing was terrible, so adjust the dioptre properly as detailed previously. If you can...
Posted by johnriley on 30/12/2011 - 19:58
Completely Dejected (auto focus K5)
This one was EV 0.3 so pretty dim, not expecting much here, Auto Focus (single point on the large letter T of the word "The" on the left of the page.) Please could you explain how you calculated the EV as 0.3? Your EXIF says 1/80 at F1.4, ISO 400. I may be misreading the table , but if it's...
Posted by ChrisA on 30/12/2011 - 20:03
Completely Dejected (auto focus K5)
An EV table, taken from Carl Shipman's Pentax SLR Cameras book. These tables are based on ISO100 and an f1.4 lens. Any combination of aperture and shutter speed that is equivalent to the ones given will give the same EV number.
Posted by johnriley on 30/12/2011 - 20:27
Completely Dejected (auto focus K5)
Thanks John. So if I've understood this right, F1.4 and 1 second would be EV -1 at ISO 400? So EV 5 would be 1/64 at F1.4 and ISO 400? That corresponds with the wiki table - so I'm still unclear where the EV 0.3 comes from. Of course, EV 5 isn't particularly low light at all. If that ...
Posted by ChrisA on 30/12/2011 - 20:39
Completely Dejected (auto focus K5)
Why can't they put the EV value on the LCD panel? A Pentax Spotmeter gives it directly as it's reading to 0.3 EV I'm not sure if it's displayed on the camera if you set it to spot? Edit: My Gossen Sixtomat Digital gives them as well currently about EV 5 in the living room... not very brigh...
Posted by Algernon on 30/12/2011 - 20:47
Completely Dejected (auto focus K5)
A typical tungsten exposure might be more like 1/60sec at f5.6 using moderately powerful photoflood lighting, but I suspect that we're thinking here more about wanting to use ordinary room lighting. To be honest, that's dreadful lighting for a portrait, if indeed that's what we are talking about....
Posted by johnriley on 30/12/2011 - 21:23
Completely Dejected (auto focus K5)
That last test was rough-and-ready but more meaningful. For more usual apertures the DOF would mean focus was close enough, but for precision focusing you'll need more light by the look of things. Your manual focusing was terrible, so adjust the dioptre properly as detailed previously. If you can...
Posted by Daydreamjay on 30/12/2011 - 21:52
Completely Dejected (auto focus K5)
To be honest, that's dreadful lighting for a portrait, if indeed that's what we are talking about. Images that appear to be natural room lighting are probably extensively augmented by additional hidden lights, thus giving reasonable exposures. A portrait was just an example. So what if the picture ...
Posted by ChrisA on 30/12/2011 - 22:45
Completely Dejected (auto focus K5)
Seriously mate did you read my post, I said I adjusted the diopter from one extreme to the other and the the error was still consistent. I'm sure he did read your post. Adjusting it from one extreme to the other is not the same as adjusting it correctly for your eye.
Posted by MarkTaylor on 30/12/2011 - 23:37
