karma mechanic

Joined: 25th September 2007

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karma mechanic
In snappychappy's rather effective shot above there is some of the Sun showing through the branches. For the small area of the sensor that is falling on it is exactly as bright as the rest of the Sun, so it doesn't matter if it is the whole Sun or just a part - if it was going to damage the sensor it would do so.

Anyone with a wide-angle, especially something like the Pentax 15mm, is likely to take many shots with the Sun clearly in the picture to get the 'starburst' effect. I still haven't heard of any reported damage.

Point'n'shoot compacts with live view viewfinders must have the Sun in the picture in billions of shots, and with those the sensor is exposed to it for seconds or minutes rather than the 1/4000th or so that is likely on a DSLR.

Comment by karma mechanic posted on Shooting directly into the sun can damage sensor? at 14/10/2011 - 17:41

karma mechanic
The sensor is only exposed to the sun's image for the time of the exposure, and assuming the metering works that's likely to be a very short time indeed.

There are millions of wide-angle shots with the sun in them, but I've never heard of sensor damage caused by that.

Comment by karma mechanic posted on Shooting directly into the sun can damage sensor? at 14/10/2011 - 11:51

karma mechanic
I think the best way to do this is for a seller to offer an item on here for their preferred price, but to also say that it will go on ebay if unsold. Then everybody should be happy*




*Figuratively speaking.

Comment by karma mechanic posted on K-7 body on eBay, London sale at 14/10/2011 - 09:36

karma mechanic
That's a very effective image, and I do like the way the b&w gives it impact and a 'reportage' style.

You asked for C&C, so I'll say that I'm not sure about the amount of space above the head. You could try cropping that area to about half-way between the top of the head and the top of the frame, this would reduce the slight distraction of the white area on the right.

Comment by karma mechanic posted on when we finish.....the liturgy??? at 13/10/2011 - 08:55

karma mechanic
Disassembling the lens to fix the aperture mechanism would have involved the position of the front assembly being changed. Very slightly, but there's no guarantee that it is in exactly the same position as before. This in turn means that the AF might need to be fine-tuned, so you have done the right thing in attending to that.

One scenario worth considering is this - the lens had a fault with an aperture blade. Could it be that the pictures taken before the repair were not at the aperture you expected? Let's say it was effectively stopped down slightly before due to the loose blade. Shots you thought were at f/4 might have been effectively (optically) f/5.6, so perhaps slightly sharper. The exposure would have been adjusted by the camera, and it was commanding the lens to give f/4 so that's what you'd see on the body and in the EXIF, even though the optical path was subject to a 'real' f/5.6 due to the blade problem.

Or something like that, depending on what apertures you were actually using.

How did you notice the loose pin in the iris mechanism?

Comment by karma mechanic posted on Lens seems soft after repair at 13/10/2011 - 08:41

karma mechanic
Does it show anything on the rear screen at all?
Certainly worth trying a different card if possible. Is this a card that previously worked?

Comment by karma mechanic posted on Pentax istD Problem at 10/10/2011 - 10:40

karma mechanic
The endorsement in that link is so preposterous that for me it weakens any claim the stuff might have - it makes it looks like a scam. Which would be a shame if it is simply a good cleaner.

Comment by karma mechanic posted on Lens Cleaning at 08/10/2011 - 12:44

karma mechanic
I'd been thinking along the lines of a painterly 'still life' of fruit and the good doctor did it straight away, so I went and took cameras to bits instead

Well done to all, and it certainly got me thinking about that particular style and why it is effective.

Comment by karma mechanic posted on Entries Fortnightly Competition # 77: Chiaroscuro at 07/10/2011 - 10:46

karma mechanic
Just looked into the throat of a DL2 (Samsung GX1L) and the screen definitely has the enclosing drop-down frame and clip and the little tab for handling. I'll check a DL later when it arrives. Nothing in the manual of course.

Comment by karma mechanic posted on WTB Pentax ist Focusing Screen at 05/10/2011 - 10:10

karma mechanic
tyronet2000 wrote:

I'm hoping to get an IR filter and try out on an old *ist DL2 which I believe can be used for IR with a filter. Not keen on having it modified at mega bucks though
The DL2 will certainly work well with an R72 filter, it will give hand-held exposures in bright sun - just. You'll need to take a manual white balance off sunlit grass, and preferably shoot RAW. The AF will still work reasonably well because the AF system is also seeing IR. My article over on the right will shed more light on it

Comment by karma mechanic posted on Another simulated IR at 02/10/2011 - 10:31

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