Clean sensor

I have a question to ask of all you lucky people with your myriad of lenses - How do you keep your sensor clean when you change your lenses?

Also, I am considering replacing my DL2 kit lens and a Sigma 75-300 APO with one lens. I have seen a Sigma 18-200 when I have done a search through google and a Sigma 18-125. Can you please advice as to their relative merits. Yet another question - a lot of adverts show lenses with a hood attached, is it advisable to have it on?

Thanks for your patience.

Howard

I don't keep my sesnor clean is the simple answer.
I always change lenses with the camera pointing down, to minimise dust, but it always gets in. I clone out the dust till it gets too bad, then use a Giotto's Rocket to blast the sensor, followed by my Visible Dust Artic Butterfly brush. Works fine. I haven't yet had to move on to a wet cleaning system.
In Tanzania I stuck to my Tamron 28-300 to avoid lens changing in such a dusty place, but otherwise it is too limiting to stick to just one lens. You might as well go for an upmarket P&S.

Looking forward to being able to afford a K10D with it's built in sensor cleaning though!

I only turn the hood round when I need it, otherwise it sits in its parked position on the lens, but I know some have it on all the time as a bit of extra protection for the lens. Makes storing them difficult though.

We have had our *istDs cameras for around 18 months and have never had to clean the sensor, nor have we had any dust marks.

Change lenses as little as possible, always point the camera down when changing lenses, always switch the camera off when changing lenses. Avoid dusty environments.

A lens hood is always a good idea as it reduces the possibility of flare.

I change lenses I suppose more than someone with zooms as I now only have primes. I have had dust on my sensor since 3 months into Pentax DL ownership. Just recently more dirt was visible on the sky portions of images. I tried a blower with varying degrees of success what has worked is the Artic Butterfly that I recently got, I had to do about 4 wipes and then it was clear.

My *ist-D has been cleaned loads of times
Have used Pecpads+Eclipse fluid, also sensor swabs with fluid. All work pretty well, but you can never get 100% of it out - so there's always the patch and clone tool in Photoshop!
(Having seen a pro's 1Ds RAW file that was covered in stuff, I don't get worked up about it so much now )
Matt

I remember having all sorts of issues with my *ist-D which I'd bought from SRS as one of their "A-Grade"... It ended up going backwards and forwards to Pentax UK to be cleaned 3 times before it was sorted. There were some 'orrible grubby marks on it

Since then I've cleaned it twice using the same method as Matt - I picked up the pads and eclipse fluid from warehouseexpress.com

It's a fairly simple job to do, takes a few mins and a nice steady hand... so no doing it at this time of night when you get back from a couple of Ales!

Will

I had my D for years before I needed to clean the sensor, and I have a LOT of lenses. I just got the Sensor Swabs and Eclipse fluid.

It was a bit nerve-wracking the first time, but it worked. Now I feel fine about sensor cleaning.

Yeah I bought a used Sigma 18-125 and like it a fair bit. I made comparison shots between the lower end of the 18-125 and the Pentax 18-55 kit lens. IMO there was little to choose quality wise, so I sold the kit lens which contrary to the view of many Pentax users I didn't really think much of.

Now I do agree with reports by other buyers of the 18-125 regarding inconsistent auto focusing in low light. Its a bit like pot luck if you rely on it. Sometimes I notice it focuses correctly at first try but if you lift your finger off the shutter button then half press again this A/F may try focus again and get it wrong leaving you with out of focus subjects.

What I do is look through the viewfinder and check the subject really is in focus before I take. What puzzles me is the focus light on my K100D is also fooled.

So IMO if you're shooting professionally or fast and don't have much time to double check focusing then this is probably not the lens for you. But for my needs and the handiness of not changing lenses continually I find its a good thing to have as a general always on the camera lens despite its drawbacks.

I'm getting the impression from reading various reviews that the Sigma 18-200 is a better lens for Auto focusing but the FOV @ 200mm is more like 180mm say compared to equivalent Pentax zooms.

The Tamron 18-200XR DiII is a superb lens, a little slow on the ist DS but superbly fast on the K10D. Do noticable distortion, even at extremes, and good clarity / colour.

As for lens cleaning I change lenses a lot in very dusty African conditions and agree with others, always point the camera down when changing lens. I don't we clean but use an Air Cannon (very lightly) from a good distance. Cleans it great.

Thanks to everybody for their suggestions.

I think I'll have to save more of my pennies to get one of the Sigma lenses or possibly the Tamron. And I'll have to be more careful when changing the lenses I have to keep the sensor clean.

Howard

I have this lens and IMO it's very good compared with the price. The main problem I have experienced is that it has more barrel distortion at wide angle compared to Pentax 16-45mm and that the coating is not as good as in an SMC lens.

What I want to know is how to clean the screen. My DL has had dirt on the top part of the screen from 2 months old! The sensor is no problem to clean since I bought Artic Butterfly. It is the focussing screen that is the pain for me. I wonder if dust etc gets into the top part of the focussing screens on the new K cameras as quickly. It doesn't affect photos, but it is surely annoying to see it in the viewfinder.