Search results for 'sensor cleaning' - page 148
K10D what Lenses should I or CAN I get?
Sorry, but you're being given inaccurate information. DG simply means they are compatible with full frame. DC means they are not compatible with full frame and for crop sensor only. So, DG lenses work with crop DSLRs but will also work with 35mm format cameras or full frame DSLRs (not that Pentax...
Posted by Blythman on 14/06/2012 - 08:33
K10D what Lenses should I or CAN I get?
This is for sigma lenses,from their web site. APO (Apochromatic ) In order to attain the highest quality images, the APO lens has been made using special low-dispersion (SLD) glass and is designed to minimize color aberration. ASP (Aspherical) The aspherical lens complex allows freedom ...
Posted by montyaus on 14/06/2012 - 10:22
Radioactive Takumar M42 lenses
We all know about certain Takumar lenses and their radioactivity (not Alpha radiation though - thank god!) Alright on film bodies, but what happens on Digital bodies? Obviously the sensor is electronic, but would the radiation from these lenses damage or at the very least affect the image the sens...
Posted by Offertonhatter on 21/06/2012 - 19:56
Radioactive Takumar M42 lenses
I once visited a company that sterilised medical materials using short bursts of hi-energy radiation. Part of the safety proceedures required before the lethal rays could be unleashed was that they had to check there was no one in the chamber. This was done with 'hardened' video cameras, actually...
Posted by Frogherder on 21/06/2012 - 20:47
Radioactive Takumar M42 lenses
Typical low energy alpha particles would be of little concern in this sort of application as they are stopped by the thin layer of dead skin on the outside of your body, or a few cm of air, the glass of the viewfinder would be quite enough to stop any getting to your eye. They only become a signific...
Posted by petrochemist on 21/06/2012 - 21:40
mirror lens or a 2x converter
And don't forget that compared to 135 format, on APS-C a 500 becomes 750 and a 600 becomes 900. Great for getting closer, but it means your technique needs to take this into account. For my shots of the bottle, there was enough 'shake' visible in the finder to make the framing a challenge in itse...
Posted by kh1234567890 on 30/06/2012 - 16:03
mirror lens or a 2x converter
And don't forget that compared to 135 format, on APS-C a 500 becomes 750 and a 600 becomes 900. Great for getting closer, but it means your technique needs to take this into account. For my shots of the bottle, there was enough 'shake' visible in the finder to make the framing a challenge in itse...
Posted by johnha on 30/06/2012 - 17:39
mirror lens or a 2x converter
[quote:3496ace15f="johnha"]And don't forget that compared to 135 format, on APS-C a 500 becomes 750 and a 600 becomes 900. Great for getting closer, but it means your technique needs to take this into account. For my shots of the bottle, there was enough 'shake' visible in the finder to make the ...
Posted by kh1234567890 on 30/06/2012 - 18:24
which wide to hire for Olympic Park architecture?
Milamber like you if I could find a secondhand 8-16 I would jump at it. It seems that 10-20 is a bit of a 'marminite' lens hence plenty around seconf hand, whereas I suspect that the 8-16 is held onto by those who buy it, which says a lot. The Sigma 8-16mm has their new FLD glass in it (it stands f...
Posted by MrCynical on 06/07/2012 - 01:29
The FA 50 F1.4 and the K-5
Strange title, but let me explain. I love my nifty, but today I was taking some shots on my K-5 with wide apertures. Guess what, the CA is appalling! Large edges of magenta cast... On earlier DSLR bodies (DS, K10D and K20D) it is okay. But on the K-5? Well I think it has reached its limit. Sure i...
Posted by Offertonhatter on 08/07/2012 - 21:02
The FA 50 F1.4 and the K-5
Somewhere in the distant past :mrgreen: It's also been pointed out in lens tests such as: http://erphotoreview.com/wordpress/?p=511 "The K-7 sensor is inferior in ways, but not in all. It is definitely better with purple fringing. Would I take the K-5 sensor over it for most application...
Posted by Algernon on 09/07/2012 - 11:13
The FA 50 F1.4 and the K-5
Why haven't people done further, controlled, tests? I expect it's such a minor issue that no one can be arsed. Does the sensor induce a smidge more PF? From anecdotal evidence, probably, but maybe not significantly enough to warrant further investigation, and it's probably not an issue that is parti...
Posted by ChrisA on 09/07/2012 - 14:37
The FA 50 F1.4 and the K-5
It's confused by the issue that lenses create PF far more noticeably. As you have suggested, newbies could do a forum search for PF and conclude that their K5 is to blame, rather than their lens, which is probably wrong in at least 99% of cases. Similar to how every dust spot suddenly became the dre...
Posted by Pentaxophile on 09/07/2012 - 14:43
Siggy 150-500, DA*300, or something else
I have the older Sigma 120-400 HSM (i.e. no OS). It seems to focus rather well, however most lense become manual focus with even a 1.5x converter as the AF sensor generally stops working at somewhere between f5.6 and f6.3 (at lease on my K7). The only lens I have that seems consistent with my Kenc...
Posted by beakynet on 24/07/2012 - 13:57
M42-PK adapters - some personal experiences
The M42 lens thread is a metric thread, 42 mm diameter with a non-standard 1 mm pitch. It was first used as a lens mount by Zeiss in 1949 - see . It was widely used by Pentacon, Praktica, Ricoh, etc as well as by Asahi Pentax. Many third party lens makers also marketed good lenses with what was, fo...
Posted by OldTaffy on 07/08/2012 - 11:51
Lens recommendation
I'm pretty sure that Sigma make a 24-70 in Pentax mount which is a constant f2.8. I think (although best to check) that it is a full frame lens rather than being designed specifically for a crop sensor. No idea of price, although as is often the case, there are probably earlier incarnations of the l...
Posted by matwhittington on 07/08/2012 - 18:58
Thinking the Unthinkable???
No not leaving Pentax but I really miss my Limited Primes! (snip) Any wise owls out there to show me the error in my ways here? WE, the wife and I, seem to be drifting, slowly, slowly, away from the Pentaxes. We've sold off a few lenses (DA50-135, FA31 & FA43) and one of the K-5s, and invested...
Posted by Tord on 16/08/2012 - 22:03
Thinking the Unthinkable???
No not leaving Pentax but I really miss my Limited Primes! (snip) Any wise owls out there to show me the error in my ways here? WE, the wife and I, seem to be drifting, slowly, slowly, away from the Pentaxes. We've sold off a few lenses (DA50-135, FA31 & FA43) and one of the K-5s, and invested...
Posted by jules on 17/08/2012 - 08:43
Soft focus lens or soft focus filter
I can second the comment about using nylons as a soft focus filter, and the "Cokin type" filters ( I use a now defunct competitor's filters ) which are nothing more than a plastic sheet with a half inch diameter hole in the middle. The plastic is closer to translucent than transparent so the surroun...
Posted by Canada_Rockies on 18/08/2012 - 19:46
If you could only take one lens..
I only ever take one lens out and it's usually not a zoom. I hate changing lenses out of doors lest dirt gets on the sensor (it still does, actually!) I more than often fit one of my cheapo 28mm M42 lenses (Helios or Miranda) or, if I deserve something wider, my 24mm Hoya which I recently took on...
Posted by bwlchmawr on 18/08/2012 - 21:17
