Search results for 'back focus' - page 768
Pentax FA 80-320mm f/4.5-5.6 should the Barrel be Wobbly?
Thanks Clarky, Mike and Graham. Some test shots below in case anyone else has any advice. I'm still undecided..... going to measure the actual barrel movement later today. This is a shot at 320mm f/6.7 1/750th 400ASA that shows the out of focus at the edge of the frame. The manual focus is in ...
Posted by shim on 21/04/2009 - 09:18
Powerboat Racing - Carr Mill - St Helens
These are some tests using the Pentax 80-320mm zoom mentioned in another thread. All are screen caps from the original JPG's with no PP applied. I'm happy enough with the sharpness of these, even though the lens wobbles about. The first shot is 100% crop, some of the others were slightly cropped....
Posted by shim on 21/04/2009 - 09:41
Used lens prices shocking!
Recent purchases on ebay; Sigma 70-210 Auto focus, vgc £18 inc postage. Vivitar 2x teleconvertor with aperture control £5.00 inc Tokina 70-210 manual zoom £9.00 inc Pentax M 50mm f2, £8 inc. The point I am making is with Pentax you can get bargains, if you look. If you want brand new with al...
Posted by davex on 21/04/2009 - 19:58
Used lens prices shocking!
Why do people pay thousands for a painting? It's just stupid to pay so much for a piece of old cloth with oil paint on it which has been owned by a lot of people before. Back to lenses, it allso has something to do with quality. Some of the older lenses are of very high quality and quality is wor...
Posted by golfdiesel on 21/04/2009 - 20:09
Here at last! - DA* 60-250
Well, the focal length just seems weird, just mucking about on a close up shot (about 4 foot away) and the 50-135 zooms in closer than the 60-250! I guess it's not meant for close up work, will find out better tomorrow hopefully when the sun is back out! Quality wise, initial impressions are very...
Posted by Unlocker on 21/04/2009 - 21:57
Here at last! - DA* 60-250
Just had a few minutes spare and went out the back to do the 'traditional' leaves against the sky shots. Pointed it at a branch with the sun almost directly behind it at both F4 & F8, and from what I can see on the camera screen there is no purple fringing at all, will verify that when I can see the...
Posted by Unlocker on 22/04/2009 - 17:21
Here at last! - DA* 60-250
Aha, Wil at SRS obviously didn't know that one! Got some shots to go through that we just took this evening, be right back!
Posted by Unlocker on 22/04/2009 - 21:17
Here at last! - DA* 60-250
My DA* 60-250 mm arrived today courtesy of SRS Lovely looking lens well built and nice to handle. I swapped my 16-50 for the 60-250 and did some tests later this afternoon to see if it performed as well as other examples I have seen here and other sites. All captures were tripod mounted at 250 mm...
Posted by Greytop on 24/04/2009 - 22:34
Here at last! - DA* 60-250
Those shots look like your focus is off. :? Mine seems pretty sharp even at f4.0 :D Here's a link to some first shots taken outside SRS on a tripod with 2 sec MLU. 3 focal lengths at f4 and f5.6.
Posted by RichardDay on 25/04/2009 - 10:50
Here at last! - DA* 60-250
Mannesty, SR was off (tripod mounted) when I took these yesterday. I have shown f/4 -v- f/8 but I can tell you that f/4.5 and f/5.0 is not much better than f/4 with my copy. I can live with f/4 being a little soft and even f/4.5 but I wanted it usable. Quite clearly it isn't. Just as a comparison...
Posted by Greytop on 25/04/2009 - 11:00
Here at last! - DA* 60-250
Hi Richard, Yes I thought that too when I first looked at the samples, so I tried some shots with manual focus, unfortunately the same result, infact they actually looked a little worse :( Maybe I just have a bad copy :?:
Posted by Greytop on 25/04/2009 - 11:04
Here at last! - DA* 60-250
Hi Richard, Yes I thought that too when I first looked at the samples, so I tried some shots with manual focus, unfortunately the same result, infact they actually looked a little worse :( Maybe I just have a bad copy :?: Definitely, no doubt about it. :cry::roll:
Posted by RichardDay on 25/04/2009 - 11:19
Here at last! - DA* 60-250
Something from me, not a real life yet, just "from the balcony" ones. I tried some reals yesterday, but it was a bit late, sun was hidding, handheld and I've got a bit of mixed results, sometimes maybe too mixed, If weather good later on today, will try something proper. I tried one more balcony t...
Posted by piotro on 25/04/2009 - 11:32
Here at last! - DA* 60-250
If you focus on the sign and take images at various apertures the sharpness of the wall behind will vary because the depth of field will change.
Posted by johnriley on 25/04/2009 - 11:56
Here at last! - DA* 60-250
If you focus on the sign and take images at various apertures the sharpness of the wall behind will vary because the depth of field will change. ;), I do realise that John, I was talking series of photos at the same aperture. Just did a test with focus chart and... 250mm, f/4.0 defocusing manually ...
Posted by piotro on 25/04/2009 - 12:08
Here at last! - DA* 60-250
Repeated focus chart test few times and conclusion is, with 60-250 if first defocused lens towards the infinity, it has the tendency to back focussing, if defocussed first towards the min focussing distance, then it shows front focus. It still could be the K10D (or firmware 1.3) way of dealing with ...
Posted by piotro on 25/04/2009 - 12:56
Here at last! - DA* 60-250
Not long got back from SRS... the good news is that it was a rouge sample. The one that SRS replaced it with is much much better at f/4.... Now I'm a happy bunny :D Thanks again to the guys at SRS
Posted by Greytop on 25/04/2009 - 16:08
Here at last! - DA* 60-250
What is a "rouge sample":?: Not long got back from SRS... the good news is that it was a rouge sample. The one that SRS replaced it with is much much better at f/4.... Now I'm a happy bunny :D Thanks again to the guys at SRS
Posted by RadamFG on 25/04/2009 - 18:54
Here at last! - DA* 60-250
Glad you got it sorted, good to meet you. Hope you made sure they didnt give you the duff one to take back to Spain :D
Posted by Mike-P on 25/04/2009 - 19:54
Here at last! - DA* 60-250
AS far I'm aware Pentax SDM is a micromotor, with some gear to drive the focussing system. HSM is a ring motor. Some people believe HSM is faster (I guess as it may have lower inertia "on the back" (?)), and being more reliable due to less mechanics inside (?), both are silent anyway ;), I wouldn't ...
Posted by piotro on 25/04/2009 - 22:35
