Thanks for the replies. The focusing problem seemed to become worse when I started using my newly acquired 77 ltd so thats why I asked if a lens could have a fault that could cause this.

After googling I found that the autofocus mechanism was under the reflex mirror and so I thought if this is dusty then cleaning it could improve the situation so I took a brillo pad, only kidding, micro fibre cloth and gently cleaned it. I have since read that this was a bad move and I have probably damaged the surface of the mirror which has probably made the autofocus accuracy worse??

My K10d is a little hit and miss regarding autofocus. I realise that in low light or low contrast situations this will be the case.

Would a dusty reflex mirror or dirty focus screen affect autofocus performance?

My centre point indicator is not perfectly central in the screen. Is this crucial?

Could the lens be faulty?

Any comments would be much appreciated

I recently purchased a 15mm da ltd and after two weeks of use I can see what appear to be two large specs of dust inside the lens when I look into the front of the lens. It is not necessary to hold the lens up to the light with the shutter open to see them. Is it normal for a lens to become dusty so easily?

Would Pentax clean the lens under guarantee. Should I even bother to ask?

Any comments would be much appreciated.

I think Terry is correct. If that link is a recent image I can see dust marks and your sensor needs a clean. Can you recommend a good kit.

Thanks again

Thanks for the quick response. It is at 100% I see the noise and at 100 iso it is in the dark areas. Just one thing it seems more prevalent when I use my old lenses.

So infact even at iso 100 I should expect to apply some noise reduction especially if under exposed?


Thanks again

I have recently noticed that my images, even at 100 iso, appear to have more noise. Could this be due to the fact that I haven't cleaned my sensor in 1 and half years??? I have used the blower once or twice. I am one those who is a afraid of cleaning the sensor because of cost if I XXXX it up.

So could a dusty sensor = noise??

Any comments would be much appreciated.

I recently purchased a 35-105mm A lens and the image I have taken tend to suffer from flare and CA. I am hoping an addition of a hood will help. Can anybody give advice regarding third party lens hoods.

I saw a used cheap lens hood for Canon 35-105mm lens. Would I be correct to assume that if it fits my lens it will do the job?

I am in tokyo where there are quite a few shops selling used gear. I found them at this link


link

I recently purchased an M135 f3.5, first manual lens, and I was so impressed that, as I needed a lens with a wider field of view, I decided to buy an M 28mm f3.5. Second hand lenses in Japan are so expensive that it was cheaper to import from Adorama but as that lens was not in the excellent condition they advertised I returned it. Now I am not so keen to buy from the internet. So another problem is that I haven't seen an f3.5 M for sale anywhere in Japan, but I have seen many 28mm f3.5 Takumars (still $140 - expensive) and was wondering if anyone could be so kind as to enlighten me as to how the Takumar compares with the M.

Oh dear now that I know this if I do return the lens I will constantly be comparing images and probably will convince myself that the original lens was better and wish I had never changed it!

Is there any info on bubbles having no effect?

Does this mean that the glass 70mm is of higher quality than a 70 without bubbles. Then the resale value must be higher. Oh dear no chance of my dream FA 31mm at a cut price is there

I am very happy with the performance of this lens so why replace it? A brand new lens is one reason but knowing Penax they probably would keep it for weeks and replace the glass. The saying if it ain't broke don't fix it is running through my mind.

I am still not sure what to do

Thanks for your comments