In response to David Storms post; “Is this the reason why SDM lenses need to be used often and are prone to fail? I did seek the opinion of ASAHI PHOTO who recently replaced 4 SDM’s for me and have deep experience in this specific issue.

ASAHI Photo are dedicated Pentax lens repairers and their principal electronics engineer, has many years of experience on this work has specifically in all things to do with, control system electronics, lens design and engineering over many years.

He explained that SDM's have been problematic for all makes over the years, including Canon but many SDM's have been changed with no further problems and as the capacitors are part of a PCB (micro circuit board) and therefore cannot be changed as an individual component, are not considered as a contributor

The circuit boards "on extremely rare occasions" have been a problem but in his experience it is practically speaking always the SDM that is defective in almost all cases.

Pentax SDM's have been quite unreliable on the DA* series but again not all SDM's fail, as is my experience.

As regards the failing SDM’s: ASAHI Photo believe the specific cause relates to the integrity of manufacturing clearances between the annular components (rings) which can be badly affected by dimensional inaccuracies (out of tolerance).

Also as the clearances are minute then it must follow that any deterioration in cleanliness, surface integrity or roundness can also create problems,

ASAHI Photo is the go to place for Pentax lens repairs in my experience and are not only great to deal with but also undertake rigorous testing post repair before releasing the lens.

They guarantee their repairs in writing and from a cost point of view; “like for like SDM replacement” is around 50% less than other well known repairers.

My discussion was with Pramath see, full contact details below:

Asahi Photo Technical  
6 Albany Parade, High Street, TW8 0JW Brentford

Email: [email protected].

• Principle contact for photographic equipment repairs is PRAMATH – 02082328111

I have both and they are as good as it gets but "hunting" is dependent on numerous variables some of which such as:
# contrast of the subject against the background,
# the ability of the user to keep a fast moving bird on point,,
# the changing contrast and brightness of the image generally when panning on a bird,
# the relative size of the subject in the view finder,
# the continuously changing distance between you and the bird; there are so many things going on
TO NAME BUT A FEW

If you are not trying to take photos of fast moving smallish subjects then Pentax lenses are pretty good but if you are a BIF photographer then your skill and preparation is more important

Frankly I do not try to "follow focus" or track a fast flying bird bird in AF mode in the hope that the auto-focus system will keep up - AF is switched off; I ensure I have pre-focussed and switched off anything that is in continual processing mode or can cause the shutter operation to lag as I am following that bird.

For example Exposure is set manually, anti-shake is off, the camera is in totally manual mode and I simply position myself so that I can pick up the blurred image in the viewfinder and as it becomes sharp at the pre-focussed point I release the shutter.

I have had the top end birding kit in both Canon and Nikon too and frankly it is just the same issue more or less .

Camera / Lens combinations will hunt to varying degrees; less of course if you are taking a large subject, moving not to quickly with good contrast.

A heron in ponderous flight can be captured in auto mode on just about any camera/lens set up but a returning Puffin at 10 meters, or a stooping hawk is a different ball game.

Sorry to sound like a "Jobe's comforter" but that is my experience over many years, I have not cracked this issue and I would be genuinely most grateful if some one could educate me on this subject because my keeper rate on fast flying birds is still no better tan 20%.

Hunting is what it is - a lens and camera trying to lock on to a subject (not necessarily a moving subject in some cases) but clearly hunting is far more likely in challenging situations like BIF or a black cat running in a dark environment.

Great pictures, great week-end by the look of it.

Regards
Regards

Very interesting post David and I just sold a very tempramental DA* 50-135, (2nd one I gave up on) and had 4 other SDM's changed by ASAHI Optic (On 4 other DA* lenses).

Two of them never ever failed or played up, one of which was the DA* 16-50, reputed to be the most unreliable, the other was 200mm.

I changed the SDM's as a precaution in case I sold them in the near future.

The other two lenses having new SDM motors was 60-250; at best tempremental at worst just wouldn't wake up some times; the 300mm would usually wake up if I turned the small screw drive "dog" on the base of the lens with a small screwdriver.

However since ASAHI OPTIC changed the originals for the latest SDM's not only are they 100% reliable, no matter how long they are in the drawer, but they seem to be " crisper" and faster focussing.

However the latter point regarding focus speed has not been measured.

Going back to your point David, the questions for Ricoh ( or Johnsons Photopia) might be;

1. Would the capacitor be changed when an SDM is changed
2. If not and the capacitors are the real culprits then the newly fitted SDM's will be
affected sporadically
3. Are the latest capacitors uprated from the originals.

The only thing I am sure about is that the failures were random in frequency and " stubborness" ( if you know what I mean).

I have been using the HD 150-450 for birds over the last year which is an absolute rock, but last week I took the 300 and 200 out and it is obvious they are quicker focussing in comparison.

By the way ASAHI OPTICS are not far of "half the cost" on replacment of SDM's compared to other, and they are very knowlegeable so I will see what their view is regarding the capacitor discussion, it is a very interesting point though.

Regards

Great work Gareth, as always. Very nice pp, I agree with a previous comment, super image for B&W too.

Regards

Lovely image; very skilfully composed to convey a sense of tranquility as well as abandonment perfectly.

Regards

Very interesting / curious article ( I think ?).

Regards

http://petapixel.com/2016/04/28/11-stupidest-things-photographers-say-gear/

Certainly enjoyed this lovely set Nigel, summer at it's best, captured so well

Regards

Great creativity and skill Gareth , like all of them but particularly 1,2 and 3;

Regards

This is as good as British Wildlife photography gets; stunning captures of a furtive, difficult subject.

Regards