[dtrego]

Its a wee L shape, 22mm vertical, 4mm horizontal, width at base 12mm, width at top with the V is 6mm, the notch "V" is a gnats over 2mm deep, centred on the top 6mm.

Here's a snap of the sight from my copy. It was loose when I got the lens. I tried to tighten it up, but half the head of the screws (both of them!) practically fell off. I suspect that a previous owner or the shop where I purchased it overtightened them and fatigued the screw heads. I was able to back the screws out without resorting to a screw extractor or having to drill them out, fortunately! Still need to locate some suitable replacements someday...

[Kerrowdown]

Yep the lock screw is shown in the bottom of the lens in the picture of Kerrydown's K500/4.5.

You can also see the lock screw in the bottom left of the picture of my K500/4.5.

Phil.

Didn’t realise that was there for that purpose, thought it was holding that bit on.

Will play with that once I get back to base.

[Kerrowdown]

Here's a snap of the sight from my copy. It was loose when I got the lens. I tried to tighten it up, but half the head of the screws (both of them!) practically fell off. I suspect that a previous owner or the shop where I purchased it overtightened them and fatigued the screw heads. I was able to back the screws out without resorting to a screw extractor or having to drill them out, fortunately! Still need to locate some suitable replacements someday...

Aye that’s the very fellow.

[gofour3]

Didn’t realise that was there for that purpose, thought it was holding that bit on.

Will play with that once I get back to base.

Here is a copy of the manual, which shows the rotating body function:

Pentax K Series Super Telephotos

The manual link is a bit dark, I have the original so let me know if you want me to scan any pages.

Phil.

[Kerrowdown]

Here is a copy of the manual

Thanks very much, I'm oot and aboot for a few days just now on business, when I get I get back to base camp I'll follow the instructions on this lens...

Thanks for the offer.

[nod]

Last shot as a Pentax owner (unless I get lucky with the raffle).

OK, this weekend I wanted to try out the 500mm on cricket to get a bowler, or get the blood moon. Unfortunately yesterday severe weather hit, the blood moon was not visible and the rain stopped play. However in a 5 minute gap I dragged the tripod out tonight with a better B+S head on it and shot the moon at it's furthest point away. There's a link here to the full jpeg (1.1 Meg), but on a slow bandwidth connection is might be better to follow this link and have a look at the smaller gallery with a couple of 100% crops. It was shot on ISO200 at 1/30th f11 on Daylight White Balance, and there's a shot showing the moon size on APS-C in relation to the frame and then two 100% crops, the bottom left of the moon showing red chromatic aberration, the top right showing.

I am particularly impressed with the top right sharpness on the craters and am sure that with some knowledge of astronomy they could be sharpened up, and not just plonking a tripod down at random and using the camera's self timer. I reckon the exposure is spot on though which is the great thing about modern cameras and being able to preview the results. I seem to remember on a clear night that the moon is f5.6 1/125 ISO 100, so f11 1/30th ISO 200 is about a stop out and I was lucky to get that.

I have to express general disappointment at yesterday's blood moon photos on today's website (BBC/news science sections mainly) and the In Pictures Section. The BBC led with an out of focus shot (still leading on the science page actually) which looked like the colour balance was totally out far too red, certainly there was no side crater sharpness like this lens took the day after, now they've replaced it with a video, but there's a fair amount of "duff" photos, over exposed ones (Sheikh Zayed Grand Mosque - Reuters), out of focus ones (Kuala Lumpa - Getty Images, Athens - AFP, Athens (again) - Reuters). I think that over the next few days the "amateurs" will soundly thrash the pros, the problem with the pros is that the pressure is on to get the images over the wire as soon as possible, and for the editors to select something and in this case anything. The moon was moving rapidly across the frame when I did this, I reckon it would take about 20 minutes, there's a couple of shots by the "pros" where they tried to photograph a building or statue in the foreground. I was a film photographer so would have had more time, so I'd have got the moon exposure correctly in the background, they either cover the area of the lens with the moon with some card and done a multiple exposure for the foreground using manual focusing and having marked the lens to get both items in focus, or I'd have waited for the moon to move out before the second exposure, and there would have been plenty of time to ascertain what the correct exposures were. Having a manual aperture ring and being able to vary the focus and shutter speed would have been essential between multiples, frankly I don't know what my current camera could do on that front, I suspect many pros would not have been put in this situation before, and then with the added pressure not to wait the 20 minutes for the moon to move out, that's basically lost income so they settle and in this case I think the more measured approach by the amateur would win out.

(Sorry for not posting direct links to the photos or the photos themselves in the news, but copyright/ photo agencies/ forums etc...)

[nod]

First image is uncorrected raw from the camera, second is proving the Chromatic aberration can be corrected. These are 100% crops, though the attaching process may have reduced the quality slightly, it's knocked about 150Kb from the file size but you should get the idea of the lack of CA around the moon's edges, blue at top, red at bottom for the first uncorrected image.

I use RawTherapee when I want to play around with a RAW file (rare indeed), it can apply the camera's own tone curve and on Fuji X-trans camera's the chromatic aberration correction is under the "Transform" Tab -> "Chromatic Aberration Correction" (box is second up from the bottom), after applying a "reduced" edge sharpness of 25 under "Advanced" and turning on "wavelet levels", I apply CA correction of -0.0014 to red only which got rid of the blue too.

I have no idea about the science behind it, but it seems that anyone interested in entirely faithful colours like a bird watcher can correct the M42 500mm f4.5 and K mount (probably) ... with a very small tweak, there is an insane amount of detail in the RAW file at 100 for the edge sharpness the craters are very very impressive with some appearing where my eyes pixel peeping cannot determine a difference in tone but the software can and does, on non-fuji sensors (e.g. everything else except sigma's foveon), apparently CA can be corrected under the RAW tab, but this may work differently but hopefully I have included enough keywords so that if in the future someone needs to know the settings and that it is possible to correct, they'll find this post through a search engine.

Attached Images

View Picture EXIF

File Date

 

View Picture EXIF

File Date

 

[Tool_Horder]

Last shot as a Pentax owner (unless I get lucky with the raffle).

I am particularly impressed with the top right sharpness on the craters and am sure that with some knowledge of astronomy they could be sharpened up, and not just plonking a tripod down at random and using the camera's self timer. I reckon the exposure is spot on though which is the great thing about modern cameras and being able to preview the results. I seem to remember on a clear night that the moon is f5.6 1/125 ISO 100, so f11 1/30th ISO 200 is about a stop out and I was lucky to get that.

The Tak 500/4.5 is a very capable lens but like all super telephoto's technique & atmospheric conditions play a big part in the results. The secret is in getting to know how the lens performs & to work within its limitations. Apart from carrying it around, CA is the biggest drawback with the Tak 500/4.5 & the moon is one of those very contrasty subjects to really expose the CA problem.


However, with good atmosphere & a little processing the Tak500 can produce good results. This is from Takumar 500/4.5, single raw shot using K200D.There is still CA visible in the image but I did not concern myself too much with removing it totally as it does not distract from the image. There is enough detail in the 'overall image' that you are not drawn to the CA.

[nod]

The lens sold now, but it's very capable, as I understand it a lot of camera bodies and lens now are built with software for correction of CA and certainly it was easy enough to correct mine. Playing with the sharpness and "micro contrast" on the RAW file in RawTherapee was moving it in the direction of your much better image. I'm no expert on RAW processing or anything digital, I find it difficult to instinctively feel what kind of image I'd get out with 11+ stops of dynamic range in colour compared to 20+ years ago. I remember my first experiences of Photoshop and trying to burn in at 50% on something and it coming out way darker than what I would have expected in a darkroom and using my hands.

I was torn about selling this even though it was on behalf of my father, (I'd have paid him), I started a journey with a memory of not rating the lens very much from the film days and needing to stop it down, I ended up loving the lens and being embarrassed by the pictures by the pros with a lot more expensive gear. If I were not so disabled then I would have kept it and used it without question.

I have virtually none of my portfolio left (an acrimonious divorce and ex-wife, what remnants I have are generally reject prints which were in a differing box to the ones she destroyed), but I believe I have two Pentax shots from my days at the regionals, I am certain they are the first and last pictures I took for the regionals and by coincidence were using Pentax equipment. (the first with an ME Super, the last with an LX), both using a 28mm M series f2,8. I know the gear was Pentax because the first one was an experiment when I was not on the rota, and the last was at the end of my time in the regionals when management had changed and there were arguments about me using the paper's equipment when using time of in lieu, I was taking on national assignments.

I know I've seen the pictures around, the last is on the wall of my parent's house, both demonstrate the extremely superb flare control of SMC coating and exceptional resolution so when I can find time and equipment to scan them then I'll post them in a relevant thread. For the 500mm M42 f4.5 sales data, my father's "externally paint peeling a little" but optically sound lens, as opposed to mint, went for £267 on ebay UK, which I think is a bargain especially when I look at the results from the blood moon debacle using gear 20x the cost. Mirrorless/ Live View has really brought these back into play at an exceptionally low entry price point.