Search results for 'back focus' - page 641
Help! Lens with back-focus?!
I forgot you had an SFXn :roll: This is quite fascinating, I'm not sure about the firmware (I'd have to look into it myself) but I would imagine that your DS is working perfectly because it's ok with Pentax lenses and you have the same results when focusing manually. By that token, I would expe...
Posted by Kimbo on 17/11/2005 - 04:02
Help! Lens with back-focus?!
Ok, take a look at these pics; they're cropped and scaled, but you'll be able to see the effect even at these scaled sizes (otherwise the pics would be gigantic to post). From top to bottom, I tried to focus on the 28-80's numbers, then on the water bottle's barcode and then on the TV's remote "S...
Posted by Flink on 17/11/2005 - 08:14
Help! Lens with back-focus?!
Blimey! Matt is correct! The body is trying to focus on the hyperfocal distance! I gave it a quick try during lunch; I set the body on Aperture priority, wide open (F/3.5), point at some infinity (distant mountains) and my DS wasn't able to focus (it moved to infinity and made that sound of wa...
Posted by Flink on 17/11/2005 - 14:55
Help! Lens with back-focus?!
Interesting, I'll see if I can simulate the same thing with my DL and a Tamron (manual focus) lens + 1.7x AF adapter. The camera wont 'know' what lens I'm using and will only have the aperture and adapter readings to go by. I must admit that I have so far only used my Tamrons in manual mode but t...
Posted by Kimbo on 17/11/2005 - 15:14
Help! Lens with back-focus?!
Kimbo, thanks for your time. Indeed, you're right. None of my Pentax lenses exhibit the Tokina's simptoms. Changing the aperture does not change the focus point. But I have been doing more tests and, at 28mm, the Tokina really changes the focus point as I change from F3.5 to F8. At 105mm howev...
Posted by Flink on 22/11/2005 - 22:37
Help! Lens with back-focus?!
Flink Apparently this problem is not that uncommon. I remember a few months ago a huge go-round on Luminous Landscape about the same thing happening with a guy's brand new Canon 20D as well as his warranty relacement. It got pretty heated with several people refusing to believe Canon was shippin...
Posted by photo*ist on 23/11/2005 - 06:25
Help! Lens with back-focus?!
Flink Has anyone answered your question about how to tell your current firmware version? Check your firmware version by turning the camera on while holding down the MENU button. Your firmware version will be displayed on the LCD screen. Latest version for the *ist DS is V1.02 and can be downl...
Posted by photo*ist on 23/11/2005 - 07:42
Help! Lens with back-focus?!
Yes Drew, thanks, I had already seen the link you gave and my DS's firmware (1.0). The problem happens only with the Tokina. None of my other lenses exhibit this behavior, so there is nothing wrong with my DS. Oh, and something I didn't clarify earlier: when I said the Tokina was sharp, I didn...
Posted by Flink on 23/11/2005 - 22:12
Help! Lens with back-focus?!
just browsing and spotted this back focus discussion - i can confirm that the tokina atx pro 80-200 2.8 lens most certainly focusses wrongly in af mode, i use this lens to shoot motorcycle racing (wsb and bsb) and was puzzled as to why some shots were in and some out of focus - took a while to suss ...
Posted by Anonymous on 03/12/2005 - 21:30
Thinking of a 28
I presume you mean a manual focus version, in which case I would go for the SMC Pentax-M 28mm f2.8, compact, superb, one more element than the f3.5 version. The SMC Pentax 28mm f2 is no doubt a very fine lens, but bulky by comparison and very expensive. If you like wide angles and want to stre...
Posted by johnriley on 16/11/2005 - 07:44
Circular vs Linear Polarizing Filters
Hi, Seeing we haven't had a really dumb question for a while means Mac has been slacking-off. Well, I'm back, and need some help understanding Circular PL filters - which I believe were necessitated by auto focusing lenses being fooled by linears. - If they're circular, how come we still ...
Posted by Anonymous on 18/11/2005 - 02:20
Circular vs Linear Polarizing Filters
I'm not sure what you have when you say cutouts and frame, but I sometimes cut out shapes(hearts,stars etc) from black cardboard and tape them to my uv filter. try photographing a person with those cutouts with city/xmas lights (anything that'll make specular highlights) in the background and the c...
Posted by Don on 18/11/2005 - 14:44
300mm f4.5 F info required
I have the 300mm f4.5 F* ED(IF), which is an absolutely fantastic lens. It's very sharp: mine almost always has a 2x teleconvertor on the back, and there's very little loss of quality. It handles very nicely, and is pretty compact. The built-in lens hood is very handy, as is the tripod mount, which ...
Posted by Anonymous on 21/11/2005 - 21:58
300mm f4.5 F info required
Hi, I don't think there is a comparison. Not only is Pentax glass generally better but you are trying to compare a zoom with a prime. The prime is nearly always going to win hands down in a quality contest. I haven't used the 4.5 F version but I do have the 300/4 and the 300/4A* which are superb es...
Posted by Kim C on 25/11/2005 - 12:07
SMC M Macro 1:4 100mm K-mount lens
Hi, I'm a student, & I'm looking for a lens for my K1000 (well, Christmas is a-coming, you never know... :) ). I've been very into photography for a good while & I'd love a macro lens, but I haven't a clue when it comes to all the technical specs (like the difference between a 50mm & ...
Posted by Anonymous on 22/11/2005 - 19:08
SMC M Macro 1:4 100mm K-mount lens
All the SMC Pentax 1:4 100mm macro lenses are superb. Just make sure you don't buy the one called the "bellows macro" because it is designed to be used on a bellows, and has no other means to focus it. In the UK these lenses go for anywhere from £75 to £150 on-line (and more in the shops). Th...
Posted by George Lazarette on 22/11/2005 - 19:28
Pentax 40mm f2.8 da af "pancake"
I find it balances well on the D and the MZ-S. I tend to use it with film in place of a 28. It handles well and has a lovely feel to it that the polycarbonate lenses don't. It is also easier to use as an MF lens than most. Performance wise, it is fast and exceptional quality. About the only lens to ...
Posted by Kim C on 24/11/2005 - 14:05
Pentax 40mm f2.8 da af "pancake"
It is a new autofocus design for the smaller APS format CCD sensor, has no aperture ring, is optimised for digital capture. The SMC Pentax-M 40mm f2.8 is a manual focus lens for the M series cameras, with no A setting on the aperture ring. It can be used on the DSLRs but with limited functionalit...
Posted by johnriley on 25/11/2005 - 07:53
Fast fifties - info please!
Hi Matt, I do have a 50/1.2A but it is the special chrome version and so doesn't get used a lot!. However, one of my most used lenses is the 50/1.2K which is the same optical formula and I have had most of the variations of the 1.4 which are all similiar in performance. IMHO, the 1.7s are very good...
Posted by Kim C on 25/11/2005 - 12:00
Fast fifties - info please!
Hi Kim, Appreciate the comment a lot. Actually my F-1.7 is very sharp, and as you say, has a great flat field. I use it mostly for low level light portraiture, but manual focussing with it is horrible (not very solid construction and such a small focus ring). I thought the A-50/1.2 was rare, but...
Posted by MattMatic on 25/11/2005 - 12:08
