Search results for 'sensor cleaning' - page 124
Windolene
For any newbies; Here are some more things that are not recommended for cleaning lenses. 1. Vim. 2. Brasso. 3. Sandpaper. 4. Those washing up sponges with a pan scouring surface on the top. 5. Marmite. 6. A blowtorch. 7. Chanel No5. 8. Battery acid. 9. South African sherry. 10. Tesco Val...
Posted by mowog on 04/09/2010 - 20:04
Which Wide angle ?
I think that makes sense - I remember reading somewhere that my 18mm lens is about 27mm in compact terms - not sure whether this is true ? The size quoted on compats is most of the time the 135format (fullframe, film) equivalent. If so than 18mm on your DSLR will give the same angle of view as the ...
Posted by Anvh on 06/09/2010 - 13:19
Pentax 1.7x AF Teleconverter
I just noticed the sellers name..... Woodbine :shock::lol: Doesn't exactly inspire confidence :lol: I purchased something the other day and it absolutely stunk of smoke. Hate that and had it been bought off Ebay I would have marked them down on it. Had an ME Super a few months back with the same p...
Posted by Dangermouse on 21/09/2010 - 13:11
Fungus in lenses
Personally I've used white vinegar or normal optical cleaning spray successfully to remove fungus, just dunk a cotton bud in either and swab the fungus away.
Posted by Dangermouse on 10/09/2010 - 12:43
What primes would we like to see?
I would love to see something from Pentax in the range of 400/500 or even 600mm . . . This is already available. If you marry a Pentax DSLR to a SMCP-F 1.7x AF TC and a DA*300mm, you have the 35mm equivalent FOV of 765mm at a fraction of the probable cost of a 600mm lens. I doubt you used anything l...
Posted by gillbod on 14/09/2010 - 11:21
Focus Shift on Stopping Down
There is no golden rule that says a lens will be at its best at f8. High quality modern primes may well be at their best at f5.6, or even f4. In theory, lenses should perform best at open aperture but we know they don't - this is because no lens is a "perfect lens" so there are compromises in its de...
Posted by gillbod on 14/09/2010 - 11:14
Any advice on choosing a AF teleconverter?
the rule of thumb is the higher the magnification, the greater the loss of IQ (and light, obviously...but this can be offset by going to higher ISO with newer bodies). So its a trade-off, unsurprisingly. However, I've never quite understood the point of a 1.4x TC, it seems such a marginal increas...
Posted by flossie on 14/09/2010 - 08:49
Any advice on choosing a AF teleconverter?
However, I've never quite understood the point of a 1.4x TC, it seems such a marginal increase in zoom... (and little different than getting a higher-resolution sensor, or just doing a bit more cropping, which for anything less than billboard-sized printing shots isn't really an issue nowadays...) P...
Posted by Algernon on 14/09/2010 - 09:59
Any advice on choosing a AF teleconverter?
In the Pentax 1.4 AF converter the elements move to producing the autofocus. It works with any manual focus lens 2.8 or wider. The f/2.8 is very conservative. It might have been to do with the earlier SFX AF sensor not being as sensitive as digital stuff. I've used the 1.7x and 1.4x on a 55-300mm at...
Posted by Algernon on 16/09/2010 - 12:01
disassemble DA 55-300
Does anyone know how to disassemble DA55-300mm for cleaning fungus inside the lens? I tried to open the rear mount. Then find it hard to continue after take apart the amount. Besides, I tried to open the front glass by finding a notch in the front ring. yet none there. THen I take off the cover the...
Posted by Johnivy on 16/09/2010 - 07:55
disassemble DA 55-300
Thanks everyone. I bought it as second hand. new and cheap but it turns out there are two fungi. With my university student budget, I don't think it is worthy to clean it in pentax service center. Then after watching many examples of disassemble lenses for cleaning. I made up my mind to dismantle it...
Posted by Johnivy on 16/09/2010 - 09:27
disassemble DA 55-300
The main problem I have with cleaning fungus is dust. You can spot and clean the fungus easily but you will inevitably get some dust inside when you rebuild the lens. A can of compressed air does help! You may also have fun resetting the infinity focus depending on the lens design. I tend to ...
Posted by Dangermouse on 16/09/2010 - 15:02
best kit lens replacement
"I was a bit disappointed after comparing the results of my k-x with a friend of mine (sony A900 with excellent lenses), Mostly about contrast and sharpness." A "full frame" sensor (eg. Sony A900) with excellent lenses is going to knock spots off your camera/lens combination pretty well whatever ...
Posted by wadna on 07/10/2010 - 10:40
Please explain macro lenses too me !
Hi Justin, There are two factors you need to consider: magnification ratio and working distance. A 'true' macro lens is one capable of capturing the subject on sensor or film at 1:1, that is to say 'life size', or greater. Some 50mm macro lenses capture at 1:2 (half-life size)unless coupled wi...
Posted by prsjnb on 01/10/2010 - 10:40
confuse by all type of mount.
I just bypassed a Pentax-made lens because the guy had been using it on his Canon camera. DID Pentax manufacture lenses with other types of mounts? Or could this guy have a Pentax-to-Canon adapter on the lens and not know it? Some Canon users do know Pentax lenses are top performers, so they per...
Posted by pentaxian450 on 01/10/2010 - 17:15
wide-angle lens
I have recently bought a Sigma 18-250 which, so far, I am more than happy with. The Sigma 18-200 got some poor reviews, but the 18-250 is a vast improvement. It is a bit bulkier and heavier than the Pentax/Tamron versions, but more solidly built. It also has HSM, which I think is a serious advantage...
Posted by aliengrove on 04/10/2010 - 11:29
wide-angle lens
I have recently bought a Sigma 18-250 which, so far, I am more than happy with. The Sigma 18-200 got some poor reviews, but the 18-250 is a vast improvement. It is a bit bulkier and heavier than the Pentax/Tamron versions, but more solidly built. It also has HSM, which I think is a serious advantage...
Posted by abesad on 04/10/2010 - 12:13
How many primes?
How many prime lenses, specifically designed for the APS-C sensor have Pentax made?
Posted by mowog on 11/10/2010 - 19:27
UV filter or No UV filter?
UV is already cut out by the lens coating and the filter that's in front of the sensor. As for protection, that's only needed with very old lenses just look at this The front element is very hard to scratch and even if you did you will hardly notice it on your photo, just put a corner of a pos...
Posted by Anvh on 13/10/2010 - 20:50
UV filter or No UV filter?
Now, please, may I impose on your best of British knowledge of these L v's not L variants of the 18-55. And ask if you could kindly clarify for me if and roughly when then was a version I of the beast, and then a version II seemed to appear on the scene? And if the change was introduced at some p...
Posted by thoughton on 14/10/2010 - 12:46
