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Forum: Pentax Q 10-06-2020, 06:34 PM  
Now you can order a Metabones K to Q Speedbooster!
Posted By Sykil
Replies: 108
Views: 7,028
Indeed! I wasn't sure if I would like it any better than the M 50/1.7 at first, but they're very different and I feel like they both have a place.
Forum: Pentax Q 10-05-2020, 05:48 PM  
Now you can order a Metabones K to Q Speedbooster!
Posted By Sykil
Replies: 108
Views: 7,028
I cry. I even managed to get my hands on a cheap K 50 / 1.2 that would be fun to try with this.
Forum: Pentax SLR Lens Discussion 09-12-2020, 07:35 PM  
DA 21: defective?
Posted By Sykil
Replies: 13
Views: 921
DoF preview.
Forum: Photographic Industry and Professionals 09-10-2020, 08:51 AM  
Should Pentax Focus Their Limited R&D Resources On "Stills" Cameras?
Posted By Sykil
Replies: 71
Views: 3,812
That's not much different from Leica, really.
Forum: Pentax Camera and Field Accessories 09-09-2020, 08:52 AM  
Adaptist PK+MM installation and usage
Posted By Sykil
Replies: 114
Views: 8,247
Those sensors are not curved. The effect you are referring to is likely due to the microlens array or possibly the sensor stack, not sensor curvature. Unless you have a source, I have no reason to believe this. Nothing I have read online points to the A7 or A9 cameras having curved sensors, which would absolutely be noteworthy.
Forum: Pentax Camera and Field Accessories 09-08-2020, 09:03 PM  
Adaptist PK+MM installation and usage
Posted By Sykil
Replies: 114
Views: 8,247
Uh, as far as I know there are no curved sensor cameras on the market yet. Certainly no enthusiast / professional ILCs.
Forum: Pentax SLR Lens Discussion 09-06-2020, 12:08 PM  
Lens Recommendations For K-10D
Posted By Sykil
Replies: 16
Views: 905
A plastic fantastic 35 / 2.4 could be a good, cheap place to start.
Forum: Pentax News and Rumors 09-04-2020, 02:11 PM  
Product Stories of New APS-C
Posted By Sykil
Replies: 501
Views: 42,182
You're right that it is arbitrary, but flagship is generally used to mean a top of the line, feature-complete product for which most of their research and development is specifically conducted rather than repackaged pre-existing technology with minor iterative changes. With how sparse Pentax's release schedule has been though, yeah, the distinction doesn't necessarily mean as much to many people as the fact that they're releasing a camera at all. I'm not really complaining - I only have used equipment anyway ( this stuff's expensive!), and in general I'd like for healthier and more sustainable turnover in the tech industry. I suppose it's also a bit odd to people when you call your APS-C a flagship when you also sell a full-frame camera, and though the K-1 II isn't that old, there are things that people would have liked for then as well as some great tech advancements since. A K-1 successor/update that included a BSI sensor could be the bee's knees. I'd be unlikely to buy it on release anyway... but, you know, it would be cool.
Forum: Pentax K-1 09-01-2020, 07:12 AM  
Tight knob issue
Posted By Sykil
Replies: 6
Views: 613
I've had a used K-1 a little more than a month now and I only move it from ISO to turn wifi on. :lol: The dial is nice and clicky, so it didn't take too long to learn how to switch without looking. Exposure compensation could be convenient too, especially since it's right next to ISO, but there's already a reasonably convenient button on the camera for that...

But back to OP's question, my "third control wheel" is adjustable with just a thumb and a good bit of pressure, but it is rather stiff and more comfortable to adjust with two fingers, so I think Steve is right that your black one is probably "broken" (which is only a problem insomuch as it bothers you) and the silver is working as intended.
Forum: Pentax Medium Format 08-31-2020, 09:34 PM  
Lens recommendations for adapted 645 primes
Posted By Sykil
Replies: 12
Views: 814
The GFXs and digital 645s have the same sensor dimensions, and the 645 lenses are made to cover an even larger 6x4.5 negative — even the newer ones, I believe. They should cover the sensor just fine.
Forum: Troubleshooting and Beginner Help 08-31-2020, 06:18 PM  
Pentax mount adapter K M42 adapter problem
Posted By Sykil
Replies: 15
Views: 845
My K-1 does the same thing. It's generally not a big deal other than sometimes it dislodges a bit at the extreme end of the focus ring. But I've been shooting a lot with a big, heavy 200 / 3.5 Takumar mounted to it lately and it hasn't been a problem. To get the mount off, I'll either just unscrew it from the lens or put it in another mount that doesn't release when I go to unscrew the lens. I have a *ist DL, K1000, and two K-mount lens adapters for the Q that all securely hold the M42 adapter. I'm not sure why the K-1 doesn't.
Forum: Pentax SLR Lens Discussion 08-26-2020, 04:40 PM  
Half-Step Aperture Value Incorrectly Labeled!
Posted By Sykil
Replies: 34
Views: 1,432
I'd much rather it be labelled by f-stop for predictable depth of field. Having to take the shutter speed down a click is pretty much never going to ruin your image, and you can raise the ISO if need be.

I'd still love for manufacturers to publish t-stops in their specs, but unless it's at or better than the competition it doesn't really benefit them from a marketing standpoint - and often the pursuit of better image quality necessarily comes at the cost of t-stop performance.
Forum: General Talk 08-26-2020, 03:35 PM  
Your latest acquisition
Posted By Sykil
Replies: 21,639
Views: 1,561,292
Got my first Takumar in from Japan today: the 200 / 3.5. There are a handful others I'd like to try, but this seemed relatively unique between the preset aperture and (slightly unnecessary) 18 diaphragm blades, so when I found one with the hood and collar for a decent price, I sprung for it. :D
Forum: Pentax SLR Lens Discussion 08-26-2020, 12:19 PM  
Do I sell DA lenses to fund a DFA lens?
Posted By Sykil
Replies: 30
Views: 1,710
On the HD 10-17 (i.e. the newest version) you can remove the hood and get unblocked circular edges, which is nice.

The 17-28 is great if you specifically want to translate the 10-17 view on APS-C to full-frame, but it has issues. The minimum focus distance is not nearly as good, and the lens has a reasonably common (but repairable) problem with the distance scale and potentially focusing. Which reminds me that I got one for $30 that I need to repair.
Forum: Pentax News and Rumors 08-25-2020, 11:06 AM  
New APS-C is
Posted By Sykil
Replies: 1,045
Views: 73,590
"The Camera Formerly Known as K-3"
Forum: Pentax News and Rumors 08-23-2020, 10:03 PM  
Another snippet from Pentax HQ
Posted By Sykil
Replies: 410
Views: 31,298
I'm not seeing one, but I might just be blind.

I remember the K10D having one, though. Mostly I just liked fidgeting with it - it was an On/Off switch like the usual AF/MF one, but otherwise it stayed on all the time.

EDIT: Ah, I found some pictures where the lock button says SR instead. I think those are older mockups/prototypes but I'm not sure. It's hard to make out but the one in the article is definitely a lock button, at least.
Forum: Pentax DSLR Discussion 08-23-2020, 09:24 AM  
Focus Stacking In Camera Using Intervals?
Posted By Sykil
Replies: 11
Views: 944
Hugin / enfuse was going to be my suggestion as well. Unfortunately I don't know of many FOSS GUI options.

Really though, I'd still do it manually with layers (layer masks are useful but not necessary) in GIMP. It's pretty easy. You're just using a feathered eraser or selection to get rid of out-of-focus areas in everything above your base layer. G'MIC is a very useful GIMP plugin if you don't already have it. I don't think it has a module specifically for focus stacking, but it has a lot of useful tools for aligning and compositing images from layers as well as other useful photo editing tools.


As for OP's interval composite idea, you should get a sort of soft-focus effect with that method, which I don't think is what you're going for.
Forum: Pentax SLR Lens Discussion 08-17-2020, 11:16 PM  
Physical diameter of the lens
Posted By Sykil
Replies: 35
Views: 1,630
The lens doesn’t change; you’re just capturing a crop of it that represents a smaller field of view. The 50mm medium format lens is still a wide-angle lens.

Assuming a rectilinear lens, field of view of the image captured by the sensor can be determined by the sensor dimensions and focal length. From that you have rough categories of focal lengths that you can call wide, normal, narrow or whatever relative to that format. These are conventions that have developed over time mostly relative to the 35mm film format.

But wide, normal, telephoto, etc. are properties of the lens. A rectilinear 25mm designed for Micro 4/3 (e.g. image circle diameter just enough to cover the sensor diagonal) is not a wide angle lens. Ever. Not on a smaller sensor, where the image circle is cropped to a smaller field of view, and not on a larger sensor, where not only does it not cover the entire sensor — it is fundamentally not designed to capture light from that wide of an angle.

When the lens is specifically designed for that format, defining wide/normal/narrow by focal length relative to sensor dimension and by focal length relative to image circle diameter are basically the same thing. But, yes, that falls apart when you look at lenses in general across different formats and designs. In photography full-frame is often assumed, but formats are pretty diverse now in the enthusiast still photography world. More generally, those definitions refer to the lens because there are unique design considerations based on the angle you’re capturing, not only in terms of just capturing a rectilinear image of that angle, but also controlling aberrations and distortion, which is particularly tricky for a wide angle.
Forum: Pentax Q 08-17-2020, 08:49 PM  
Now you can order a Metabones K to Q Speedbooster!
Posted By Sykil
Replies: 108
Views: 7,028
Maybe it will herald the end of COVID. You know, when the world ends.

:[
Forum: Pentax SLR Lens Discussion 08-17-2020, 08:38 PM  
Physical diameter of the lens
Posted By Sykil
Replies: 35
Views: 1,630
Forum: Pentax SLR Lens Discussion 08-17-2020, 04:12 PM  
Physical diameter of the lens
Posted By Sykil
Replies: 35
Views: 1,630
Sure, magnification is the same on the intended image plane, but either way that has nothing to do with f-stop.
Forum: Pentax SLR Lens Discussion 08-17-2020, 03:41 PM  
Physical diameter of the lens
Posted By Sykil
Replies: 35
Views: 1,630
Subject magnification is measured relative to the size of the sensor, so it does not stay the same. And that's just how crops work; it doesn't have much to do with the lens otherwise. The rest doesn't really have anything to do with my point, which is that if you have a 50mm wide angle lens with the same physical diaphragm as a 50mm normal lens, the 50mm wide angle will have a higher maximum f-stop (e.g. smaller maximum entrance pupil) due to the necessary differences in the way they're designed and the effect that has on the entrance pupil.

The same lens is the same lens. Exposure is the same because they're literally looking at the same image circle, so the crop is exposed to the same degree as that portion of the full-frame sensor. But I'm not talking about identical lenses.
Forum: Pentax K-1 08-17-2020, 03:24 PM  
Question about compatibility of APSC-designed lenses with K-1
Posted By Sykil
Replies: 16
Views: 1,492
There are pros and cons to smaller and larger pixel pitches, but a full-frame sensor trumps APS-C in image quality whether when you hold either megapixel or pixel pitch equal. It has either better data or more data with which to construct an image, respectively. Larger sensors cost more to source because they're made on wafers, like CPUs, and split up. Larger area means fewer sensors means you're paying a premium to Sony or whoever is manufacturing your sensor.


DSLRs are not primarily designed for astrophotography where pixel pitch is important because it is, in a sense, extreme macro photography. Dedicated astrophotography cameras also tend to use smaller sensors / image circles so that lenses have longer reach.
Forum: Pentax SLR Lens Discussion 08-17-2020, 12:18 PM  
Lens mount
Posted By Sykil
Replies: 11
Views: 906
The extra lever bit sticking out makes me think no. Nikon, perhaps?

Actually I can't tell exactly what is happening at the top there.
Forum: Pentax SLR Lens Discussion 08-16-2020, 09:30 PM  
Physical diameter of the lens
Posted By Sykil
Replies: 35
Views: 1,630
I am not. F-number is calculated by the diameter of the entrance pupil, which is an optical image of the physical opening, not the opening itself.

Remove the front element of a wide angle-lens and you’ll see that the diaphragm is larger. Remove the front element from a normal lens and you’ll see that the diaphragm is smaller. 50mm can mean wide-angle, normal, telescopic — it depends on the image circle (and thus angle of view) that the lens is intended for. The f-numbers will be different in each case even if the physical opening inside is the same diameter.
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