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Forum: Pentax SLR Lens Discussion 3 Days Ago  
Samyang super wide/fish eye
Posted By Lowell Goudge
Replies: 23
Views: 645
I have the 14/2.8 and the 8mm fisheye, but don't use them for landscapes, I prefer longer lenses for landscapes because they will make the background mountains look insignificant.

The one thing I do use ultra wides on is for looking up both in forests and in cities with skyscrapers,

Also note that while the 14mm is quite wide on full frame it exhibits a good amount of barrel distortion

Both lenses are quite good on lens flare which is important considering how wide they are.

P.s. I also have a zenitar 16mm full frame fisheye that is a lot of fun to use on a crop sensor, I haven't tried it yet on full frame
Forum: Pentax SLR Lens Discussion 11-08-2018, 07:16 AM  
Best Pentax lens collection I ever saw in my life
Posted By Lowell Goudge
Replies: 82
Views: 10,344
the really sad thing to reflect upon here is something all of us will face at some point.

who will want our "stuff" when it is our time?

what will your descendants do with your photo gear when you no longer can use it? will they want it, or even appreciate the value of it?
Forum: Pentax SLR Lens Discussion 11-03-2018, 04:08 AM  
I think I bought the wrong(?) 200mm F4 Manual Lens!
Posted By Lowell Goudge
Replies: 7
Views: 741
I have the SMC Takumar, (same optics but screw mount) and it is a steady performer, but prefer the earlier Takumar 200/3.5 preset lens, for what I think is better overall rendition,mand less lateral CA than the 200/4 super Takumar/SMC tak/K which are all the same except for coatings

But for the price you did just fine
Forum: Pentax DSLR Discussion 10-29-2018, 06:03 PM  
The End of the DSLR?
Posted By Lowell Goudge
Replies: 223
Views: 8,334
I said one format , also said for telephoto.

I agree there is a potential saving on wide angle because you may not need a retro focus group with a short registration distance,
Forum: Pentax DSLR Discussion 10-28-2018, 04:54 AM  
The End of the DSLR?
Posted By Lowell Goudge
Replies: 223
Views: 8,334
I don't get the whole discussion.

For any format, yes a mirror less body will be smaller than a DSLR, but for any format, a lens is a lens is a lens. An 85mmF1.4 has to be the same size regardless of mirror less or not. And batteries etc, all take the same space.

So unless you are only discussion the wide to normal range, there is no big advantage in size and weight.

People like to use Leica as an example, ok, look at their line up, not overly fast, but they are designed to be used wide open. So sure a body and a pocket full of gold (sorry lenses) and you can travel anywhere. Relatively light, but you can do the same with Pentax too.
Forum: Pentax SLR Lens Discussion 10-25-2018, 03:56 AM  
Lens hood info for SMC Pentax K-50mm F1.4
Posted By Lowell Goudge
Replies: 15
Views: 617
Search for a file I uploaded years ago called hoodcalc.

It allows you to find the maximum length of a hood for a given diameter. While rubber hoods work to a certain extent they may be much wider than the minimum, meaning you are still a little restricted shooting into the light.
Forum: General Photography 10-23-2018, 04:17 AM  
F 50/1.7 | M 28/2.8 | Mamiya/Sekor 35/2.8 | Helios 44K-4 - side by side night shots
Posted By Lowell Goudge
Replies: 5
Views: 378
Although I appreciate the effort in this post, it needs to be moved, the idea of the image archive is to have one lense and one lens only perthread

I will ask the moderators to move this to the lens discussion forum
Forum: Troubleshooting and Beginner Help 10-22-2018, 07:28 AM  
K-30 underexposed pics - is or me or the camera?
Posted By Lowell Goudge
Replies: 30
Views: 1,078
one other thing to consider in the first and second shots. the sun is behind the photographer is there an issue with light entering the viewfinder?
Forum: Troubleshooting and Beginner Help 10-17-2018, 04:09 AM  
What's up with my lens?
Posted By Lowell Goudge
Replies: 26
Views: 1,271
Just a couple of points to note in all the posts.

First, don't jump directly to a de entered lens, look at technique before equipment failures.

The shot was 30 seconds, how stable was the platform?
The shot was wide open, and while people might argue about the wonderful DOF of wide angle lenses, and that it might be ok because it was set to its hyper focal distance, please remember, hyper focal distance and DOF are based upon a definition of relatively sharp, where a point is less than 20 microns on a crop sensor or 30 microns on full frame sensors, lets translate this to a useful term, that represents 0.1 inch when viewed on an 8x10 print. Today, we tend to blow images up to huge proportions on our monitors. So the old definitions no longer allpy, because we are viewing much larger images today.

Also, in the first print, the house eaves seem to be sharp suggesting the lens was focused very near the camera.

The op should stop the lens down perhaps to F5.6 or F8 and take a longer exposure. He should see infinitely fine lines ideally about 2 pixels wide, The acceptably sharp definition of 20-30 microns would be potentially 5-6 pixels even on my K5
Forum: Post Your Photos! 10-06-2018, 04:12 AM  
Machinery 77 Marquis
Posted By Lowell Goudge
Replies: 17
Views: 447
All of my "toys" were 60's era fords. First car was a 64 falcon convertible with factory 260 V8, the engine swallowed a valve and came apart, so I shoehorned a 351W 4BBL into it. That lasted about 6 months until the front clip separated from the unitbody. I happened upon a 66 Fairlane 500 (my avatar) with a blown engine, and put the 351 into that. Had it for 6 years. In the process I started on a 65T-Bird (never got to finish it) and my winter car was a 68 mustang coupe,

I was only the second owner of the Fairlane, and sold it in 84, but it was still on the road 3 years ago, but much tamer with a mid 70's 302.

All my friends had fast cars in the late 70's and I helped one friend put a 401ci javelin power train in a gremlin;)
Forum: Post Your Photos! 10-05-2018, 11:20 AM  
Machinery 77 Marquis
Posted By Lowell Goudge
Replies: 17
Views: 447
too bad it is the 400.

my brother once had a 73 with a 429. tons more potential than the 400m. the problem is, you likely will be required to meet either the origonal emissions standards, or if you update it, the emissions standards for the year of the power train.
Forum: Pentax SLR Lens Discussion 10-05-2018, 05:47 AM  
A rare Super takumar 50.14 eight elements?
Posted By Lowell Goudge
Replies: 11
Views: 551
i believe some where there is a thread discussing the cross over between the 8 element and 7 element in production, and while the infra red focusing dot and the A/M switch are indicators,there are some hybrid lenses where the 8 element parts appear on early versions of 7 element lens. The only definitive identifiers of 7 element vs 8 element are the physical shape of the rear element, AND the weight, the 7 element is 230 grams vs 245 grams for the 8 element. the weight is definitive, but usually you don't have the physical sample in your hands, so shape of the rear element is what people use.
Forum: Post Your Photos! 10-04-2018, 07:57 AM  
Machinery 77 Marquis
Posted By Lowell Goudge
Replies: 17
Views: 447
the last of the land yachts, what's under the hood?
Forum: Pentax SLR Lens Discussion 09-24-2018, 03:47 PM  
Sticky: (Beta) Pentax Lens Compability Checker Tool
Posted By Lowell Goudge
Replies: 62
Views: 7,518
I was thinking the flash modes the camera will support with a given lens attached, or is it because only the *istD series that support dual modes TTL and P-TTL that there is not really any more relevance
Forum: Pentax SLR Lens Discussion 09-21-2018, 11:42 PM  
Sticky: (Beta) Pentax Lens Compability Checker Tool
Posted By Lowell Goudge
Replies: 62
Views: 7,518
Adam

Great idea, one thing I noticed is you did not address flash compatibility, the *istD for example even on a Takumar lens will give TTL flash . Not sure if it is in the scope of the tool, also, and I know this is probably outside scope is third party lenses
Forum: Pentax SLR Lens Discussion 09-21-2018, 12:16 AM  
FA 20-35 unobtanium ....Not sure what to expect from Promaster 19-35 alternative lens
Posted By Lowell Goudge
Replies: 24
Views: 1,176
I picked up a vivitar similar to this, manufactured by samyang, sadly it seems to lack contrast.

I would suggest the FA-J 18-35, this is what came with my original *istD
Forum: Pentax DSLR Discussion 08-17-2018, 10:33 AM  
Fun thread: If you were given $5,000 to spend...
Posted By Lowell Goudge
Replies: 163
Views: 3,672
true, but currently i use a 70-200/2.8 ex with TC, and have no issue with extra weight so the 500/4.5 would be a good selction, plus i have already the 1.4x TC from sigma
Forum: Pentax DSLR Discussion 08-16-2018, 04:41 PM  
Fun thread: If you were given $5,000 to spend...
Posted By Lowell Goudge
Replies: 163
Views: 3,672
Easy. Sigma 500/4.5, then see what's left over
Forum: General Photography 08-14-2018, 10:51 AM  
Is this formula accurate for hood length?
Posted By Lowell Goudge
Replies: 15
Views: 624
while i agree with the second point, the only way to determine the first is to have a before and after test with and without the hood. note that many lenses have light fall off, , not vignetting exactly of up to 2-3 stops in terms of exposure value between middle and edge when wide open and it is almost impossible to detect without making a measurement.

but common sense suggests if you use the sheet, then simply take the maximum length and take it back a few mm. also since the hoods, unless you are making it yourself , are in fixed sizes, you simply pick the next one in sequence that is shorter than the spreadsheet predicts is optimum
Forum: Troubleshooting and Beginner Help 07-28-2018, 03:54 AM  
Sigma 70-200 f2.8 EX APO (non-hsm) - troubleshooting and/or worth the repair?
Posted By Lowell Goudge
Replies: 5
Views: 521
Even at 75 pounds it would be worth fixing. This is one of the sharpest versions of the lens, especially at 200mm and wide open

If and when my copy does, I don't know what I will replace it with. But it is 15 years old and going on strong
Forum: Troubleshooting and Beginner Help 07-18-2018, 04:50 PM  
Pentax-M 135mm tripod or handheld?
Posted By Lowell Goudge
Replies: 16
Views: 765
Ether use of a tripod serves 2 purposes' first it slows you down and as a result you think and compose more, second is image stability

With respect to image stability, without in body stabilization three is a "rule of thumb" from film days that the recommended minimum, shutter speed was 1/focal length.

This rule was for a full frame 24 X 36 mm film or sensor, printed to 8 inches by 10 inches. The concept w based upon the principle of acceptably sharp, meaning a point source or infinitely thin line appeared on the 8x10 print as no bigger than 1/100 of an inch

The problem with digital is that we now tend to zoom in when inspecting the image to much greater than this, so now acceptably sharp becomes a discussion of how big do you intend to view or print the image, and how tightly you crop after capturing it

Your question was wide open what focal length needs a tripod, but that is the wrong question as you can see from what I wrote above. If you are going to print / view 8x10 then 1/125 should do, if you go to 16x20 then 1/250 etc

But wide open with an M135 unless it is ally dark, you will need more than the above shutter speed just to get proper exposure
Forum: Pentax Camera and Field Accessories 06-22-2018, 05:01 AM  
Thinnest arca-swiss compatible tripod plate available
Posted By Lowell Goudge
Replies: 33
Views: 1,518
i can only relate a recient experience i have had.

i use a tamron 200-500/5.6 zoom, that weighs about 3 kilos all by itself.

i tried using a regular tripod head with but changed to a gimball head, a jopbo jr to be precise.

the gimbal has a pivot and an L Shaped arm that hangs down from the pivot, to mount the lens.

this arm is 170 mm long, 8 mm 13 mm thick at the edges (but milled to 8 mm thick in the middle to save weight.

while it seems rigid enough, looking through my 500mm lens, the whole thing bounces, removing this plate, and connecting my same acra swiss adaptor direct to the pivot removed all of this.,

with a 5mm thick plate your lens simply will not be stable. this is real world experience. you can try, but it is likely not worth it.

i am actually looking to replace my 150mm aluminum plate which is 10mm thick with a piece of oak 22 mm thick.
Forum: Pentax Camera and Field Accessories 06-21-2018, 06:21 PM  
Thinnest arca-swiss compatible tripod plate available
Posted By Lowell Goudge
Replies: 33
Views: 1,518
The stiffness of a plate is directly related to the thickness. Your long heavy lens will flex and lead to serious vibration of the lens on the tripod.
Forum: Pentax Camera and Field Accessories 06-21-2018, 04:06 AM  
Thinnest arca-swiss compatible tripod plate available
Posted By Lowell Goudge
Replies: 33
Views: 1,518
For a camera and a short lens, I can see a thin plate working, but for a long lens, where the tripod mount location is where the optics allow it to be, as opposed to where balance with a camera suggests it should be usually dictates you need a long plate to balance the lens.

A5mm plate is simply not rigid enough to prevent vibrations
Forum: Pentax Camera and Field Accessories 06-18-2018, 03:06 PM  
Thinnest arca-swiss compatible tripod plate available
Posted By Lowell Goudge
Replies: 33
Views: 1,518
You could probably purchase 6-7mm aluminum strip 40 mm wide and cut a groove with a carbide tipped table saw blade, but as others have commented a heavy lens probably will wobble and shake.

It might work if the tripod foot is balanced and has multiple screw holes, but for my tamron 200-500/5.6 where I n d a 10-12cm plate just to balance the camera, it would be too thin.

The ideal solution would be to have lens makers cast the shape into the mount
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