Balsam was used ages ago to join two lens elements. It has a refractive index same as glass so was very popular then. But aging affects the glue and separation starts from the lens periphery. This will show up as flare and blur around the edges.
I had a Zeiss binocular with this problem. Just soaked the lens in alcohol for a week and pried the two lenses apart. Removed the balsam coating by gently scraping it with my nails. Cleaned the surfaces with alcohol. Put the lenses together without any gluing and and assembled it back. Worked fine.
Did not notice any perceptible difference except for some slight color fringing between the two eye pieces.

Here is the cheapest source for a possible repair. Do tell them to apply multi coating too. He did an excellent job for of re-coating an old Rolleiflex f2.8 Planar lens. The only condition is you send him the glass and NOT the lens, since he is a manufacturer of optical glass and not a repairer of lenses:-
Mr. Mukul Garg
http://www.universaloptics.in/ [email protected]
UNIVERSAL OPTICS.
D-1, INDUSTRIAL ESTATE.
ROORKEE - 247667.
(UTTARAKHAND)
INDIA

Here is a guy in the US. But be prepared to pay 4-times as much:-
Focal Point Inc.
303-665-6640
[email protected]
300 Center Drive
Suite G-177
Superior, CO 80027

Check out some of the old Russian Federation countries too. Cheap and very good.

Rubbing a lead pencil on the threads is a superb idea. But please do this first:- Wipe the threads with an old clean hanky pressing your nail into the threads. You will be surprised to find some dark scum on the threads. Then spray some WD40 on the hanky and clean the threads again. Note: your hanky may tear, so use an old one.
I have a kitchen tool for $ 3 or 4, for opening Jar caps. Any filter from 100 mm dia to 20 mm can be opened easily - see photo. It has a soft rubber insert which can be removed if needed. See photos attached.
Just ensure your filter screws in smoothly w/o applying too much pressure - sign of a good filter thread.

Hi Renster Sir, that was good news getting rid of the smear. But what wipe did you use?
I had a similar problem once, so I used the next best thing I had - Sears Lens Fluid, and it worked. I have lots of old filters, and prism lenses (multiple images) which I don't use much. I found them with some kind of fogginess on them. They cleaned up pretty good with the Sears Lens Fluid.
CAUTION: Never use Hospital Alcohol or Rectified Spirit, as they have some kind of oily additive in them.
At one time I bought Kodak Lens Cleaning Fluid and Lens Tissue.
Regards.

Hello Peter, I had the same problem with a Promaster Spectrum 7 100mm Macro Lens I bought "Like New" from KEH USA. Being a Master Mechanic, I used fine emery to break down the sharp edges all round the lens mount. I stuck small pieces of paper tape on critical areas to prevent accidental scratches.
The Lens then fitted just fine.
Make sure you use the emery on on all the edges - up, down and the sides. These sharp edges are called burrs and are caused by bad machining practices. You are basically removing these burrs a giving a little taper to the sharp edges. Good Luck.
Bipin - from that far away enchanting land.

Hi Mc Greg, that certainly is a great matching pair with the speckled black on both camera and lens.
Honestly I have read rave reviews about this humble lens. Wanted to buy one but ended up with a used Sigma 10-20, which is a much superior buy at almost the same price as for the new Samyang. And getting older warrants an auto focus lens, as my eyes are failing me.
Your photos are a bit bright and the colors are slightly off, sort of blown. Do use a higher contrast with the Bright mode - Fn setting. Jack up your saturation and sharpness too - +1 and +2 points respectively from the factory preset.
Good luck and keep shooting as the pictures otherwise are very photogenic.
Bipin. camp: San Mateo, California.

Lots and lots have been written in all the Photo Forums in the world on this topic - archiving photos. Here is my take on the subject, since eventually every media/method mentioned above is bound to fail/die at some point in time:-
a)follow the 20/80 rule and sort the best 20% of your photos. Take prints of this 20% on 100 year life paper. Then copy the same into a "RAID Array" Hard Drive, from which recovery is possible if one drive fails. Keep copies on the Cloud if you wish, or on other media.
b)For the rest use "Archival Gold" quality long life DVD/Blu Ray Discs, with backups on solid state drives/cheap Class 4 SD Cards. But please do not use ordinary hard drives as these WILL eventually fail in about 4 to 5 years time as per MTBF rule (mean time between failure).
c) Other media, as advanced technology becomes available.
Regards.

Hello Hardgravity Sir, why do you need a Grip at all?? Yes Yes I know all the excuses - vertical shots, extra battery power, use of ordinary AA cells, I have bigger hands, looks very Pro and hep, etc etc. I used all the same excuses to buy the original Pentax Grip, and HARDLY EVER USE IT NOW. The novelty has worn off. In fact it can be a pain/nuisance as the buttons keep getting pressed by no fault of mine.
Please use the fund to buy a faster better lens like a Tammy f2.8.
Regards.

when I resize in photo shop I seem to lose an awful lot of detail and sharpness - in fact they look awful when you zoom in.

Hi Charlotte, download the Free App "Fast Image Resizer" This app is excellent as it: a)retains exif data, b)you will not be able to see much difference in detail from the original, c) gives you many options on the file sizes, d)others.
Enjoy.
Bipin - from a far away enchanting land.

[quote:3496ace15f="Cliff-P"]Well I finally convinced my better half that investment in a Sigma 150-500 was a good Idea:
Anyway here are a few of my first attempts that are keepers, I should have had more but guess who for got to turn the OS on!! C&C welcome.

Hello Cliff, congrats for being a proud owner of a brand new 150-500 Bigma. I have read varying reports on sharpness at the 500mm end. One particular variant has a good review on the Pentax US Forum.
I envy you as I too wanted this lens for my K20D and later a K-5. All I have for birding is an old Sigma 100-300mm DL - tack sharp at 100, sharp at 200mm, but soft at the 300mm end.
Great bird shots as a first attempt Cliff. Good composition, but a tad soft. You may need lots of practice - hand or monopod mounted.
Here is some advice from a Japanese Forum. Use Bright setting (Fn menu). Boost Saturation to +1, Contrast to +3 and Sharpness to +4 Fine. Turn off noise reduction. leave SR On when using a monopod. Use 100 to 400 ISO only. Shoot RAW + JPEG at the highest resolution. Put these settings on USER mode and give your new lens a try.

Lighting is the key as other Pentaxians have said. Too much of red in the flower and bad lighting technique can throw a color cast obliterating the little bit of yellow. Note the red surrounds the yellow all around the flower overwhelming the yellow completely. If the flower is potted, move it into the morning or late afternoon sun. Use Bright mode with Saturation set to +1, Sharpness +3 Fine, Contrast +2, Hue 0. Use ISO 100. Set Auto Focus Point as Center on your camera. Try Spot metering. Play with the aperture - camera on Av mode. Use a tripod with SR Off and a Remote or 2-sec delay. Use both AF and manual to focus on the center of the flower - note if you focus on the stems, the flower will be out of focus. Post the same flower shot again. Good Luck.