Fungus can grow anywhere inside the lens. What you should not do is keep an affected lens with any others. Fungus propagates using microscopic spores and when conditions are right, they flourish and can easily spread to other equipment. When they grow on the glass, their excretions can corrode the coatings to a point that affects the image.

If you don't know what you are doing, I'd leave well alone.

Sometimes these fungal spores can be between two lenses that are part of a group. If that group is glued together, and they often are, the lens is bin fodder. Even if you get the group apart, it's not likely you'll have the equipment to put it back together again.

I partially dismantled a SMCP-A 50mm lens once to repair a stuck aperture ring. Nothing like as complicated as that which you are contemplating. Believe me when I say it's not a procedure I intend to repeat. I did fix it, but it was a nightmare.

Leave lens cleaning to the experts. If they fail, it's probably for a good reason. You will probably fail due to lack of knowledge and/or tools and you'd have ruined a potentially recoverable lens.

£400 for the 55, minus £150? That makes your FA50 £250, right? SRS has them at £159.

IIRC the GX1S is the same as the Pentax *istDS. If that is the case, your K200D should be producing superior images as it has a 10Mp sensor compared to the 6.1Mp sensor of the Samsung.

So, there is either something wrong with the camera, or something wrong with your set-up of the K200D.

It would help us to try and identify the problem if you could post some images for us to see. Perhaps the same scene taken with the two bodies (same lens) would be good. Then we can look at the settings.

Also, could you update your profile and enter your location. We don't need a full street address, just a rough idea of where you are in the world will be fine.

When you have the camera set to DOF preview, that's exactly what it does. It'll stop down the lens to your selected aperture so that you can 'see' the resulting DOF. I find it of limited value to be honest. Much better to take the shot, then review it, rather than preview it.

By doing this, you can get lucky. If you try to preview it to get it perfect, by the time you take the shot, your subject has got bored (or hungry) and gone away. That's my experience anyway.

Do try the 'focus bracketing' method, you might be surprised. You will need a willing (or dead) subject though.

Chris,

How much warranty with the K20D refurbs?
Are these factory or Langley refurbs with all originally shipped bits 'n bobs?

Mike,

To get greater DOF there are only three variables and one mission, use a smaller aperture:-

1: Light, use reflectors or more flash.
2: ISO, increase it to enable the use of a smaller aperture. Try not to increase it too much that noise becomes a problem.
3: Shutter speed, lower it to enable a smaller aperture. Not always possible with a moving target.
4: A combination of any two or all three.

Some subjects actually produce a better photograph if there is some OOF area.

Actually there is another way which I've seen used to great effect, but it only works with a static subject. Use (what I call) focus bracketing. Take a number of shots with different points of focus, then blend them in your favoured PP software to produce a totally in-focus image.

Insects are quite lethargic in the early mornings if that's a help, but I guess you knew that anyway.

Forgive me but you shouldn't hope for a decent DOF, you should set your camera to guarantee it if that's what the shot demands.

If your guesstimate of f5.6 as the aperture is correct, that's probably the reason for your disappointing DOF. Try f11 or f16. If the lights not good, up the ISO so that you can use at least f11.

That all assumes that you want a lot of your subject in focus. There will of course be times when you don't, and a larger aperture will then be appropriate.

First question: Why does the aperture show as f/0 ? Maybe the contacts need cleaning if it's an A series lens.
Second question: Do you wear glasses or contact lenses when using your camera. AF lenses are unaffected by either, but MF probably will be affected if you haven't set up your dioptre correctly.

Sorry if the following is "teaching granny . . . "

To adjust the dioptre correctly, remove the lens, point the camera at a well lit and light surface, then adjust the dioptre until the lines in the viewfinder are in focus. Refit the lens, job done.

EDIT: John beat me too it.

Using the grass in #2 as a reference, and assuming your camera was at about the same height as the dogs head, I'd say your plane of focus was just in front of the dogs nose. Operator error I think

Lilly, if you buy an Acer machine, you can get 3 years worldwide accidental damage insurance cover through Acer for around £99.00, and that's collect & return. No matter what happens to it, it's covered. The same may be true of other makes so check thoroughly, and check where the service centre is in India, or rather, that there is a service centre in India.

I've sold Acer laptops and normal PC's for years and have only had to return 1 laptop that had a faulty backlight. I have a 5 year old Travelmate something or other and it's still going strong.