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Forum: Pentax SLR Lens Discussion 3 Days Ago  
Help: Pentax-M 100mm f/2.8 vs. 100mm f/4 Macro Differences?
Posted By marcusBMG
Replies: 8
Views: 607
Please allow us the pleasure of seeing some more of your pics here - do your own thread or chip in on a macro thread...
Forum: Lens Clubs 3 Days Ago  
300mm plus Lens Club: discuss your long lenses
Posted By marcusBMG
Replies: 36,966
Views: 3,856,796
Does 12.6 x converter (exif) mean digital zoom aslyfox?
Forum: Lens Clubs 4 Days Ago  
300mm plus Lens Club: discuss your long lenses
Posted By marcusBMG
Replies: 36,966
Views: 3,856,796
Kingfisher was very obliging today. DFA150-450mm + KS2.

Forum: Lens Clubs 4 Days Ago  
Post your HD PENTAX-D FA 150-450mm F4.5-5.6 ED DC AW pictures!
Posted By marcusBMG
Replies: 2,740
Views: 399,337
I an getting quite frustrated with my KS2 + DFA 150-450mm. Persistent to and fro focus hunting sometimes fails to focus at all, often missing focus. I have been trying different settings: AFC vs AFS, spot focus vs zone focus. Any ideas?
I used MF for many of the pics of the kingfisher.





Forum: Photographic Equipment for Sale 5 Days Ago  
For Sale: Sigma DG 17-70mm f2.8-3.5 boxed etc; Adaptall 300mm f2.8 360B; PKA mount.
Posted By marcusBMG
Replies: 1
Views: 332
For sale: location UK but willing to send worldwide.
Payment by Paypal (easiest, esp if not in UK); cheque (UK only, despatch on clearing); bank transfer; cash on collection. Post charged at cost + a little bit, your choice of economy/signed for etc. I normally use Royal Mail for items less than 2kg, courier for more than 2kg. For speed and security PO special delivery is best - up to 2kg.
EU and other counties: Royal Mail international tracked and signed for, up to 2 kg. Over 2kg is very expensive via couriers etc. I reserve the right to decline to ship to some destinations.

FYI I am 100% fb on ebay, account name mr-adaptall

Sigma 17-70mm F2.8-3.5 vgcboxed with original u/m etc, caps, marumi protectective filter + hood 139

Very nice, I would say minty condition, fully tested, I will post some pics taken with the lens in the sigma thread. This is the earlier screw drive model not the later HSM model.

POST: UK courier 5; special delivery 9.95 ; EU 14.95 int'l tracked signed for; elsewhere and bundles msg me.

RARE Pentax M autofocus 35-70mm f2.8 good 39

One for you collectors and folks who actually have a pentax ME-F. I have used this infrequently but it is an excellent lens (see pics here), possibly the best 35-70mm pentax ever made. Similar to the "M" 35-70mm f2.8-4 but this has constant aperture.
I haven't tested AF mode at all, best I can say is that it looks ok, battery compartment nice and clean.

Hood and plate for tamron 360B 30
This is for you James (termy).
shipping - singapore: 12.95 int'l, 16.95 intl tracked and signed.


Tamron adaptall 360B 300mm f2.8 399

Classic fast 300, vgc. See this ebay listing for full description: item 203337650505

PKA adaptall mount 35

I have a couple of these spare. Fully tested.
OTHER: I have adaptall lenses like 23A 60-300mm, 54B 300mm, 03B 135mm f2.5, 04B 200mm f3.5; 40A 35-135mm; 28A 28-135mm; sigma miniwide 28mm.
Forum: Pentax SLR Lens Discussion 09-14-2021, 01:10 PM  
Teleconverters - Pentax v Kenko v Tamron
Posted By marcusBMG
Replies: 18
Views: 953
I've done several sets of pics comparing 1.4/1.5/1.7x tc's, using primarily my adaptall 300mm f2.8's and my DFA 150-450mm. My pentax 1.4x tc was definitely not the worst, however it wasn't really conclusively the best either - tending to best but within the errors and inconsistencies of the testing. Just emphasises that it is the base lens quality that counts really.
Forum: Pentax SLR Lens Discussion 09-14-2021, 06:22 AM  
Teleconverters - Pentax v Kenko v Tamron
Posted By marcusBMG
Replies: 18
Views: 953
You can also reference the comparisons in this thread, by myself, WildMark and others.

Teleconverter challenge Sigma vs Kenko vs Tamron X1.4 - PentaxForums.com

Also the reviews:

https://www.pentaxforums.com/userreviews/kenko-pz-af-1-5x-teleplus-shq-teleconverter.html
Forum: Digital Processing, Software, and Printing 09-03-2021, 06:51 AM  
Questions / Recommendations for a new windows desktop workstation
Posted By marcusBMG
Replies: 28
Views: 1,171
You're doing a lot more image processing than many of us with your astronomical photography MossyRocks. Whats the spec of your PC?
Forum: Digital Processing, Software, and Printing 09-03-2021, 04:49 AM  
Questions / Recommendations for a new windows desktop workstation
Posted By marcusBMG
Replies: 28
Views: 1,171
+ 1 SSD

I just quickly looked up the benchmark for your AMD cpu, which dates from 2012. On passmark its only 2,998 cpu score relative performance (for comparison, the current top end cpus are up around 87,000!). I was using a core-2 quad system until 18 months ago, and your complaints are just what i would have said about that system. Your cpu is quite a bit newer and 50% better than the core-2 quad in mine but nevertheless i would tend to put it in the same ballpark - it's old, way down performance wise compared to anything more recent. I bought a lenovo thinkcentre box off ebay for a hundred * ($130 ish) - core i7 260, benchmark almost 3x that of the old core-2 quad. The difference is considerable, indeed I have no speed/processing issues with this.

I have more than once added up doing a build vs shopping around for a box, and each time I have concluded doing a build doesn't save anything/much and isn't worth the bother (apart from simple things like upgrading graphics, RAM, or perhaps the cpu). I suggest you shop around for good spec box on ebay with a higher end i5 or i7, (or AMD equiv, but for a long while AMD really lagged intel until their ryzen cpu's came out) and higher end motherboard. The MB is also a significant factor in the higher performance of more recent boxes - better integrated, faster data transmision between the chips. The main thing indicating chip generation is the socket type. The lenovo is a socket 1155 (2011) = 2nd gen i7. Fastest i7 cpu of this gen is the i7 3770k, 6428 score. Actually the suceeding socket 1150 and 1151 cpu's aren't particularly faster (up to ~9000+), you need to jump to socket 1151v2 (2017), 6th gen I think, to get the next big leap. In any case searching by socket type is a good way to go.

Which ever way, you will have the hassle of migrating your data. Note that as long as you have at least a win 7 coa, there is no need to pay for win 10 see here.

One tech point with regards to the mobo. i always make sure there are 4 slots for memory sticks, and ideally min 6 SATA connections (easy to use them all up otherwise with dvd drive , bluetooth drive , couple of hard drives..)

At the end of the day, while ssd, more RAM etc helps it's the cpu that does the processing heavy lifting and is the primary speed factor. But I can suggest you don't need to spend anything like 2G! And for my ebay pics I use an old Lumix G1 + kit lens or pentax + 28mm or 50mm on a tripod, crop and adjust ooc jpg's in faststone, the old PC did all that easily.

* + 40 for a 400gb SSD, s/h but under warranty, +30 for matching set of quality 4gb DIMMS, plus some time adding more Hard disk slots. I can add that the upgrade was prompted primarily by a mobo fault and the need to have a zoom compliant system, which core-2 isn't.
Forum: Lens Clubs 08-30-2021, 03:08 PM  
300mm plus Lens Club: discuss your long lenses
Posted By marcusBMG
Replies: 36,966
Views: 3,856,796
Good mirror pics.

That's a juvenile gull, they carry on trying to cadge off mum and dad...
Forum: Pentax SLR Lens Discussion 08-30-2021, 02:59 PM  
A Comparison of 300mm capable lenses on the K-1
Posted By marcusBMG
Replies: 23
Views: 1,512
Thanks.

I adjusted the exposure on camera to get a centred histogram, using "M" manual shutter setting to avoid any discrepancies in Av between lenses/F stops. The tamron 60B shots aren't clipped on the histogram for the original RAW, but the white parts are catching the light. IME cloudy conditions can often be fringing conditions, something about the flat scattered light I think. Good lighting from the front will naturally minimise fringing.


Off the cuff I thought pixel wise it would be more equivalent, but just checking: K1 crop mode is 16mpx or so isn't it, so yeah, higher pixel density. Could've used the KS2..
Forum: Pentax SLR Lens Discussion 08-30-2021, 01:05 PM  
A Comparison of 300mm capable lenses on the K-1
Posted By marcusBMG
Replies: 23
Views: 1,512
NOTES/COMMENTS
1. The DFA 150-450mm is comfortably the best but given it cost 10/20/50 times as much as any of the other lenses apart from the tamron 300mm f2.8 (4x).. well it does emphasise my point that it costs exponentially more for incremental improvement.
2. Given that many of the vintage lenses show a significant gain in iq stopping down, for me it is important to show that.
3. My example of the DAL 55-300mm is optically more representative than DUB's. A good lens (but mine has sticky focus so I never use it :( ).
4. The adaptall 23A 60-300mm is demonstrably slightly short of 300mm, which I already knew from previous test pics. I have several of these, they are consistently good.
5. Conversely the 300mm f5.6 54B was a bit disappointing. In the field, comparing general results, I regard this and the 23A as comparable usually.
6. The results for the Adaptall SP 300mm f2.8 60B were a bit below par for me in this flat cloudy light. For comparison, here are results from the previous evening when it was sunny.




At middling F the lens is competitive with the DFA for resolution. This also reflects that the light is a factor in what results you can get - certain lenses can show better or not so well. I would make this comment in respect of the FA 100-300mm as well actually, the results I got out in the field (see my posts in relevant threads) are suggestive of a better lens than indicated by the results above.
7. The pentacon 300mm f4. The first crop is sharpest focus. The second is minimum CA focus (the mid point where you can see the fringing change) - there is a slight difference in position. It is an interesting question as to whether this is something inherent to the design, or showed up by the high level of digital scrutiny, or perhaps due to use on digital rather than with film. Anyway I thought it was interesting.


Forum: Pentax SLR Lens Discussion 08-30-2021, 07:52 AM  
A Comparison of 300mm capable lenses on the K-1
Posted By marcusBMG
Replies: 23
Views: 1,512
OK so ideal conditions prompted me to set up my big ol slik tripod, weighted, and shoot off with my K3-ii - apsc but similar actually more pixels relative to K1. I thought I had a tak lens cap kicking around somewhere, but apparently not, so the sunagor one will have to sub. My set up includes test ornaments owl and kingfisher. Distance was slightly less than 30m, but no room to move further.
Focus in 10x LV, mainly on the black stripes. Remote release, MLU, ~10secs delay. Shot in RAW but I just cropped the pics as is in Faststone, so the processing is just in camera. I don't think it is unreasonable to assume essentially similar processing of these pics for the comparison, however comparison with GUB's pics is more uncertain. Crop of the set up:

DFA 150-450mm - reference.

DAL 55-300mm

Tamron Adaptall SP 300mm f5.6 54B


Sigma DL 100-300mm f4.5-6.7


Adaptall 23A 60-300mm f3.8-5.4


Pentax FA 100-300mm f4.5-5.6


Pentacon 300mm f4


Tamron Adaptall 300mm f2.8



NOTES/COMMENTS below.
Forum: Pentax SLR Lens Discussion 08-29-2021, 09:15 AM  
Help Identifying Lens
Posted By marcusBMG
Replies: 6
Views: 622
Your lens sounds like, as per Steve, the 06A. This was the last of the f6.9 200-500mm lenses, being superceded by the much superior SP 31A 200-500mm f5.6.
One quirk of these f6.9 ones is that they do not work with the PKA mounts (ie no "A" functionality , but mounting and using with "M" is fine). This is discussed in the description in the lens review here.

Tamron Adaptall-2 200-500mm F6.9 (06A) Lens Reviews - Tamron Adaptall Lenses - Pentax Lens Review Database
Forum: Pentax SLR Lens Discussion 08-28-2021, 05:27 AM  
A Comparison of 300mm capable lenses on the K-1
Posted By marcusBMG
Replies: 23
Views: 1,512
Its a pity the light isn't better. The exposure discrepancy between the white paper and the dull everything else has exacerbated the haloing.

The tair matches its rep - one of the best vintage 300's, the soligor/hanimex (same lens) is better than expected for me I was not impressed by the essentially the same tokina made vivitar 300-5.5 that passed through my hands, the tokina AF zoom is similar to cosina and sigma x-300mm zooms I have tried ie just not very good at the long end, the tokina (= vivitar etc) 100-300mm f5 is better at infinity/distant focus at 300mm for sure, but result is indicative it is softish and fringy at f5, I am not convinced by the DAL 55-300mm result this lens is normally better than that, may be OOF, try again using MF/live view.
Forum: Pentax SLR Lens Discussion 08-26-2021, 05:00 AM  
Budget Telephoto Lens
Posted By marcusBMG
Replies: 33
Views: 1,348
While I agreee with you in a general sense p f, IMO there is value in the old lenses. Satisfaction is getting decent photos and the better ones are capable of that. Wildlife photography especially is opportunistic and if you don't have a lens then you don't get a pic. Plus you get on the learning curve. The trick is an informed choice of vintage lens. And I am not surprised if there is disappointment with this or that x-300mm AF consumer zoom, quite frankly most of these are a bit of a waste of time at 300mm, being slow and sub-par resolution, (the pentax FA 100-300mm I acquired a few months ago for next to nothing was a surprise exception, see my pics in the 300mm thread and the FA unlimited thread). Value, in the end, is in the eye of the beholder.

With telephotos, you pay exponentially more for incremental improvements in IQ.

Tamron "nestar" 400mm f6.9 @ f11. IMO the best of the real old 1960's vintage t-mount preset 400's. This lens has the cachet of being the only non-mirror 400mm that you can fit in your pocket.
Forum: Pentax SLR Lens Discussion 08-26-2021, 03:38 AM  
Budget Telephoto Lens
Posted By marcusBMG
Replies: 33
Views: 1,348
The qq are:

1. budget
2. photographic intent:
- > desired field of view = focal length
-> AF necessary/desired/ok without
-> prime or zoom, size and weight

For wildlife, I would push towards 400mm. 300mm tends to be a bit short, even on apsc.
There is no substitute for browsing and reading around, to ease you towards one of the options. This is a perrrenial question and there are numerous threads here eg

Any suggestions on a beginners level wildlife camera/kit under $1000 CAD? - PentaxForums.com

experiences with Soligor 400 mm f/6.3? - PentaxForums.com

Replacement for old Sigma 400 non-APO? - PentaxForums.com

Telephoto lenses for shooting tits : 10 lenses compared - PentaxForums.com

Also for info on particular lenses, as well as the reviews here there is lots of discussion on mflenses.com. The onsite mflenses search function is a bit clunky, just googling is often quicker to find a particular thread on there.
Forum: Troubleshooting and Beginner Help 08-24-2021, 01:02 PM  
Offsetting the tripod head on A* 300 mm f/2.8
Posted By marcusBMG
Replies: 16
Views: 721
As an aside, I am curious about a comparison of this lens with the adaptall 300-2.8's I have.
Forum: Troubleshooting and Beginner Help 08-24-2021, 11:25 AM  
Offsetting the tripod head on A* 300 mm f/2.8
Posted By marcusBMG
Replies: 16
Views: 721
UK. No problem sending something relatively small to Belgium.
Forum: Troubleshooting and Beginner Help 08-24-2021, 10:49 AM  
Offsetting the tripod head on A* 300 mm f/2.8
Posted By marcusBMG
Replies: 16
Views: 721
Measure the clearances as best you can (also lets see a side on pic) . i can adapt the design.
Forum: Troubleshooting and Beginner Help 08-23-2021, 12:11 PM  
Offsetting the tripod head on A* 300 mm f/2.8
Posted By marcusBMG
Replies: 16
Views: 721
I can make you an extension plate like this:
Aluminium, 3/8" threaded TM placements one fitted with 1/4" adapter, second support point as appropriate. This particular one is on a tamron adaptall 31A 200-500mm, also a very front heavy lens.
I can do this in a couple of hours, just need to customise the size.


Forum: Pentax SLR Lens Discussion 08-17-2021, 01:02 PM  
Which lens?
Posted By marcusBMG
Replies: 9
Views: 712
I assume those are 100% ie 1:1 crops.
I would suggest there is little significant difference between these 3 lenses. The more I have tried to take comparison images to discriminate between lenses, the less convinced I have become about the results, apart from very clear differences. All else can be slight focus variation, light variation, external factors eg atmospherics, internal or post processing variation. Indeed the more processing improves (tailored for a particular lens), the more significant that becomes.
That is not to say that a different image set up might not show more differences between the lenses.
Forum: Lens Clubs 08-14-2021, 10:28 AM  
Post your HD PENTAX-D FA 150-450mm F4.5-5.6 ED DC AW pictures!
Posted By marcusBMG
Replies: 2,740
Views: 399,337
Some from this summer.





Forum: Lens Clubs 08-14-2021, 10:19 AM  
The Sigma Lens Club- All lenses
Posted By marcusBMG
Replies: 2,781
Views: 454,297
This is my go to lens for general AF photography. Family get together - visit to the Pontcysyllte Aqueduct World Heritage Site. KS2.









Forum: Pentax SLR Lens Discussion 08-05-2021, 08:57 AM  
Lens comparison 18-55mm kit lens vs. Asahi Pentax m-50mm macro f4 lens
Posted By marcusBMG
Replies: 19
Views: 1,134
An interesting comparison and not unexpected - I think the long end of the kit lens is probably its weakest point. Kit lens vs any of the 50mm standard lenses at same f is pretty much a KO for the 50mm IME.

With close up/macro shots you need to take some care. With the DoF being so small mere alignment or not being square on can cause misleading results, as can slight vibration/shake, a more significant consideration given slow shutter speeds. With regard to that, better lighting would be a big improvement.
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