Search results for 'back focus' - page 1248
PLEASE pentax: sell a pro-level digital SLR!
Just to go back to the 35mm sensor comments: With the APS sensors currently in the Pentax DSLR's you always have the option of using the older manual, or "film" lenses despite the 1.5 magnification thing. But with Pentax investing in a line of DA lenses fitted to the APS sensor I fail to see how ...
Posted by Joshua Hakin on 29/08/2005 - 20:57
PLEASE pentax: sell a pro-level digital SLR!
I agree with most of you about the DA line of lenses and how Pentax seems to be commited to APS-C sized sensors. Still, if you look at their lens development roadmap (I just did), they seem to continue their line of DFA lenses as well (they have a new "high performance" telephoto zoom in the works)....
Posted by Flink on 30/08/2005 - 09:49
Optio SV 5 megapixels LCD screen / shutter
Frank, The LCD screens are all tricky to view in bright daylight, even on the pro SLRs. Personally, I cup my hand over the viewfind to look at it, but you can also purchase "bellows" and other screen shades that make it easier to see in daylight. Most of the delay in taking a photo is in focus...
Posted by MattMatic on 06/05/2005 - 11:24
hi
Cristophe, The RAW files have much more information. You can correct white balance errors very easily with RAW, and correct exposure comfortably around +/- 2 stops (very useful). The quality is also much higher. That said, if you shoot the highest quality JPG you can still get excellent images. ...
Posted by MattMatic on 18/05/2005 - 17:39
*istD Disaster
Turn your back for a couple of minutes and you never know what disasters can happen. Today one of my youngest relatives got his hands on my *istD when I was looking the other way, I looked back in horror at the damage done. Somehow he managed to pop the focus screen and cover the mirror in littl...
Posted by McBrian on 15/05/2005 - 16:30
Digital Infra-Red
Sounds interesting John! How about framing without the R72 and then put it back for the shot?! Matt
Posted by MattMatic on 11/07/2005 - 09:25
Digital Infra-Red
I have done it using a tripod to frame and focus then add the filter and used exposure bracketing.
Posted by joelw135 on 01/10/2005 - 15:31
Digital Infra-Red
I did likewise, but found it easiest to use a Cokin P007 IR filter which slides in with less chance of accidentally altering the focus. Anyone know of an esay way go get an IR flash? I have tried covering my flash gun with an IR filter sheet from http://www.alanaecology.com/acatalog/Infrared_Fil...
Posted by Ammonyte on 09/11/2005 - 23:43
Digital Infra-Red
um, well I'd suppose so, because IR is still a different wavelength to visible light and therefore should focus at a different point compared to visible light. The problem is, most modern lenses don't have an IR mark!
Posted by Ammonyte on 20/04/2006 - 20:41
Digital Infra-Red
Good question. As most (if not all) modern cameras have auto-focus, can they 'see' infrared? If they can, and one puts an IR filter between subject and lens, thus limiting the light that the AF system 'sees' to being in the IR range of the spectrum, does it focus correctly? I have no idea, do you...
Posted by Mannesty on 20/04/2006 - 21:34
Digital Infra-Red
Hmmm, well there is one way to find out! (pardon me while I fiddle around in the background) The camera does seem to "hunt" for the focus, and the tests shots were almost in focus (as they were of my very untidy office I'm not going to post them!) Might be a different result outside ...
Posted by Ammonyte on 20/04/2006 - 21:39
Digital Infra-Red
My guess is, no, AF systems can't focus on infrared. If they did, they'd get awfully confused in daylight as there's got to be some infrared content in daylight. Icould be (read probably am) wrong. I would try this myself . . . but I don't have any IR filters . . . yet.
Posted by Mannesty on 20/04/2006 - 21:48
Digital Infra-Red
Truth is, if you can see it, it ain't infrared. The human eye, which is what most of us are equipped with, can't 'see' wavelengths that fall into the infrared part of the light spectrum as it is outside our range of visual sensitivity at wavelengths longer than about 800nm. The red light that y...
Posted by Mannesty on 21/04/2006 - 00:54
No more *ist-D??
Thanks for the info. However, the *ist-DS is not similar IMHO :( There are too many features the *ist-D has that make the *ist-DS a non-replacement: * AF button on the back (I live off this button) * Finger wheel and thumb wheel for immediate choice between Av and Tv overriding * Pop-up flash s...
Posted by MattMatic on 24/06/2005 - 15:35
No more *ist-D??
"Just a thought, could it be that Pentax may be introducing a repalecement for the *ist-D at Photokina this year" fingers crossed but i am not holding my breath :cry: i have had the ISTD since september last year and just love it of cause there is a few things i would like changed seeing the IS...
Posted by just greg on 28/06/2005 - 08:50
No more *ist-D??
Basically, the *st D has a feature set that is easy to use on the job. It doesn't have "scene" modes to clutter up the dial. Pretty much all functions can be accesses while holding the camera up to your eye. It is a pretty common pattern among camera makers to bring out the full pro model first...
Posted by Arthur Dent on 01/08/2005 - 20:03
focusing problems
Ist DS camera My SIGMA 18-125 lens appears to be giving me a problem. When I focus while the lens is in wide angle mode and then zoom in the image is out of focus. It's only in WA that I have a problem. If I zoom in and focus (auto) and then go to WA to shoot it's not a problem. Has anyone el...
Posted by Anonymous on 26/06/2005 - 01:18
focusing problems
I'm not a lens design expert but I always understood that this is normal - most so called "zoom" lenses should properly be described as "vari-focus". Very few lenses are "true" zooms. I stand to be corrected here.
Posted by Terry1100 on 26/06/2005 - 07:58
focusing problems
I think you will find that this is normal behaviour for a lens construction where its overall length changes as you adjust the zoom. Older Pentax/Takumar zooms (mine is a Takumar-A 70-200mm Macro circa 1984) have a dual-function sliding/rotating barrel to adjust the zoom/focus and the overall length...
Posted by Mannesty on 27/06/2005 - 14:59
focusing problems
A zoom lens that retains the focus setting throughout the zoom range is termed para-focal ;) My Tokina AT-X 24-200 is parafocal. It works a dream on the Z1, but on the *ist-D it does not - apparently the camera focuses at the hyperfocal distance, which of course changes with focal length. So, ...
Posted by MattMatic on 27/06/2005 - 15:06
