Search results for 'back focus' - page 1178
DA* 60-250 Modification for Full Frame
There is a precedent going back to the Spotmatic. The f/2 version of the Super Takumar 55mm lens was the same as the f/1.8 version, but with a baffle to restrict the aperture.
Posted by johnriley on 30/06/2016 - 23:41
Sigma 70-200mm | Faulty lens?
Hi all, Quick question. I have used my recently purchased Sigma 70-200mm II HSM twice now. Once on the K5 briefly and again today with the K3ii. On the K3ii today the lens would intermittently stop working though. The AF wouldn't work and the bit in the camera top screen where it shows what typ...
Posted by cardiffgareth on 02/07/2016 - 19:41
300mm v 150-450mm
the thing to think off as well is are you thinking of going why dont you have a word with chris and see if he can do you a deal on ether of these lens if you hire them to try you never know you may get the hire price back for them both if you buy the lens there is no harm in asking he can onl...
Posted by stu62 on 03/07/2016 - 19:47
300mm v 150-450mm
With wildlife on the K3 I still end up cropping to magnify the image further. The 300mm and 1.4 tele acts as a close up lens for much I take. I get that for motorsport etc you would probably want a zoom. The adapter instructions hint at two stops down for the tele converter. I find it fine used wide...
Posted by wvbarnes on 06/07/2016 - 10:20
60-250 af fine adjustment issues
Hi all Thought I'd ask here before taking any further as I'm really not sure if I maybe over playing my expectations. A few months back I purchased a used 60-250 from SRS. I almost exclusively shoot motorsport now. First time out I was rather disappointed with the results but I put it down ...
Posted by Puggy on 05/07/2016 - 14:56
60-250 af fine adjustment issues
As if that post is not long enough will add that I regularly shoot mf so I'm not talking about camera failing to keep up with target but If making quick adjustment I like to switch to af to confirm focus is where I want it, for instance focus on the end of some armco or kerb before switching back to...
Posted by Puggy on 05/07/2016 - 15:02
60-250 af fine adjustment issues
Firstly, a black speck would not normally show on images. It would have to be huge to make any difference. Black is good because it won't cause flare spots. However, a large speck isn't what we'd expect to find in a new lens. I think we need to look at technique here, as I'm a bit baffled as to w...
Posted by johnriley on 05/07/2016 - 15:25
60-250 af fine adjustment issues
Another thought. If using AF to focus on a point, use centre point only. Maybe your camera is choosing different points every time it focuses?
Posted by johnriley on 05/07/2016 - 15:26
60-250 af fine adjustment issues
Hi John. Thanks for your thoughts and prompt answer. Maybe I didn't explain what I meant very well with regards to switching between mf/af. Take for instance shooting through the fence at oncoming cars coming out of the chicane at Donnington the ideal shot is the car on two wheels as it clips ...
Posted by Puggy on 05/07/2016 - 16:31
150-450mm focus adjust
Ive been finding my 150-450mm a bit soft at 450mm f5.6. So I took a couple of shots of a chart (which I had to colour in the focus point with black pen), focusing with liveview on, using back button focus and 2sec delay while mounted on a tripod. The chart was roughly 45 degrees to the lens. Im n...
Posted by NeilP on 17/07/2016 - 21:25
150-450mm focus adjust
Couple of real world shots to demonstrate the issue. At 270mm: At 450mm. Note the lack of fur detail I suspect there may be a lens issue
Posted by NeilP on 19/07/2016 - 07:24
150-450mm focus adjust
Does it make any difference using the focus buttons on the lens?
Posted by RobL on 19/07/2016 - 08:08
150-450mm focus adjust
My reading suggests that a number of owners found the lens soft at the long end, but noticed improvement when stopped down to 6.3 and 8. Equally, a number say it's very sharp wide open at the long end, so lens variation, technique, who knows? It's a rare lens that performs really well wide op...
Posted by JohnX on 19/07/2016 - 09:35
150-450mm focus adjust
I'm having similar issues with my new 150-450mm. I used it for the first time last Wednesday taking nearly 500 shots with my K-3. I found shots taken at around 400mm seemed much clearer & sharper than at 450mm (see my thread 300mm v 150-450mm). I sent some sample images to SRS and waiting to see w...
Posted by gwb67 on 19/07/2016 - 10:19
150-450mm focus adjust
That target doesn't look much good as a test for sharpness. Try something with fine detail such as beer bottles. Roof tiles although at a longer distance than wildlife are good for checking focus and sharpness. 450mm should not be soft. You could change it for the excellent Sigma 150-50...
Posted by Algernon on 19/07/2016 - 12:46
150-450mm focus adjust
I think you're right Neil, it is front focussing very slightly. At this focal length that will make all the difference between 'sharp' and 'not sharp', which is one of the reasons why I stick with the DA*300mm. With Primes, there's no variable focussing dependent on focal length, an issue that has...
Posted by davidstorm on 19/07/2016 - 22:12
150-450mm focus adjust
In the K-1 you can apply AF fine adjustment to the individual lens, don't know about other bodies.
Posted by RobL on 20/07/2016 - 08:10
150-450mm focus adjust
You can fine tune most of them especially K5, K3 & K1 models. I use www.pentaxdslrs.blogspot.com Look for the auto focus adjustment chart on the right hand side and download it. I use on all my cameras to date and it works well....
Posted by madmax on 20/07/2016 - 13:04
150-450mm focus adjust
Not found an issue with mine, It even bests my DA*300 + 1.4x TC. You have to be spot on with the focus though and very still. It's still not great focusing on moving targets when mounted on a K-3 :( https://www.flickr.com/photos/k_paxian/albums/72157670182307936 https://www.flickr.com/photos/k_pax...
Posted by SteveEveritt on 21/07/2016 - 22:56
150-450mm focus adjust
One of the best moon shots I've ever seen :)
Posted by tyronet2000 on 22/07/2016 - 07:41
