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Forum: Pentax SLR Lens Discussion
08-02-2021, 05:34 PM
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Good on you, Jon, we pay a lot of money for lenses and we're entitled by law to keep sending 'em back until we get one that's up to spec.
Obviously, the companies that sell the cheapest lenses have the worst manufacturing tolerances and do the least amount of quality control checking, but as Lens Rentals will tell you, there are defects and decentreing in any lens of any brand - even Canon L glass.
Since it seems to be a deliberate strategy to make the customer the defacto QC tester, we need to do the brick wall/newspaper thing as soon as we receive our purchase, and keep all the packaging in case we need to box it back up again and mail it off. :)
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Forum: Pentax SLR Lens Discussion
07-12-2021, 10:10 AM
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Testing? Comparison photos might give a good idea of what might be accomplished, but the lens is only part of that equation. Past experience with Samyang product suggests that the following should be addressed, at minimum.
Test for infinity focus. Tradition with Samyangs wider offerings has been that many lenses leave the factory unable to do fine focus much past 50m or so. Magnified live view should allow you to evaluate out to several hundred meters. I suspect that you will not find a copy of the 24mm that will have been set much further.*
Test for decentering. For this you can use the guide on this site or whatever method our prefer. My first copy of the Rokinon 14/2.8 was decentered.
How to Check Your Lens for Decentering - Articles and Tips | PentaxForums.com
Once the above have been dealt with, the best test for astro might be a few nights in the field.
Steve
* I had to nudge my Rokinon 14/2.8 a fair amount using sketchy DIY instructions found online. It may be easier to have Samyang do the adjustment.
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Forum: Lens Clubs
07-09-2021, 10:56 AM
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Forgive me if you have already done this, but a new thread might be in order for your issue. I'm sure there is help available. Best of luck.
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Forum: Photo Critique
07-03-2021, 05:17 PM
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Thank you so much. I was pleasantly surprised that I liked the crop as well. It was a great suggestion
---------- Post added 07-03-21 at 06:18 PM ----------
Thank you so much. I really was pleased with the crop suggestion. At first I wasn't sure I would like it but in the end I did. I love the fading into the clouds so I'm glad I didn't have to loose that.
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Forum: Pentax Price Watch
06-27-2021, 11:12 PM
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Forum: Film SLRs and Compact Film Cameras
06-27-2021, 04:37 AM
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My wife has a 7s. Not as fancy as the 9, it's a solid piece, and I like the way it shoots.
It isn't as elegant as some of the nicer 50s rangefinders, and it's a bit bigger, but it's a lot more sophisticated in terms of the electronics.
In my experience, many of the cameras that decouple film advance and shutter cocking aren't very smooth because they don't have to be -- they basically just drag the film over a set number of sprocket teeth and then stop. The coupled cameras have more to do, so the more complicated mechanisms sometimes end up really nice.
The Petri here, for example, despite the perspective, is a little smaller and is (to me) a better shooter, though the Minolta has a meter and is easier to deal with.
-Eric
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Forum: Photographic Technique
06-26-2021, 05:24 AM
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I'll pre-empt this by saying my comments are based on limited practice on this nightscape caper, so feel free to ignore.......still learning lots........
The shot with the Sigma 35 looks to have a lot of potential - the stars look really good (as the reviews of this lens suggest)! I'm interpreting that you have taken 4 frames of 10 seconds at f2.8 in landscape orientation then panned vertically to take the next 4 and again for the last 4 then stacked the sets of 4 before stitching the three stacks? For the satellite trails, I don't know of any approach other than cloning/or healing it out before processing. Some software claims to have options to remove it but it seems to leave faint traces behind is my experience. With the dark bands, this can be caused if you don't correct for vignetting before stacking and stitching. Need to examine what lens corrections or vignettes are being applied. I usually adjust the exposure before stacking and stitching so that you have the histogram about right (1/4 to 1/3 from left without clipping highlights or blacks) and this gives you something with a bit of room to work with on the final image. I wouldn't get too involved in it while taking the photos - shutter, ISO and aperture are all fixed by other factors. Apart from the problems you identified with bands and trails, this image should be capable of being pushed a bit to bring out more detail. You can also have a go at fixing the trails and banding by doing local adjustments on the final image - if you don't want to go back to the start images. The big downside of the night stuff is there is nearly as much or more to learn about the processing when you are sitting at the computer (yuk), and this is needed to provide the feedback loop to the field work (which is the fun bit in my opinion)
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Forum: Photographic Technique
06-26-2021, 08:28 PM
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I can't see the dark bands at PF image resolution but to clarify my comment, the vignette might be due to lens light transmission towards the edges however with an f1.4 lens at f2.8 I would think this unlikely.
If you have good star shape at f2.8, open up a bit and try f2. Might even be OK for a panorama at less as the centre of one image will sit over the edge of another and you'll increase the data collected by 2 to 4 times for a given shutter speed.
Not related I don't think but I had banding (concentric rings) when processing star trails and the solution was to uncheck lens corrections. No idea why, just is.....good luck and yes, the processing effort is high with not always equal measures of frustration and reward.
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Forum: Film SLRs and Compact Film Cameras
06-26-2021, 05:13 PM
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I have Hi-Matic 9 much like it (SN 646417). It is a very sophisticated camera.
Steve
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Forum: Film SLRs and Compact Film Cameras
06-26-2021, 03:18 PM
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In general - except for the XK that I have, all my Minolta's have a very smooth advance. I only have the one Minolta rangefinder - the Hi-Matic 9, and it is smooth. And when you fire off a shot, even in very quiet settings you can't even hear it. This is the first of the old manual cameras I acquired that was in such great condition and functionality that it lead me to explore other old manual cameras.
 Minolta Hi-Matic 9 by Les DMess, on Flickr
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Forum: Mini-Challenges, Games, and Photo Stories
06-23-2021, 02:41 PM
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 | Thematic Cats!
Posted By
pkboy |
Replies: 2,077
Views: 114,341
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Forum: Film SLRs and Compact Film Cameras
06-23-2021, 01:47 PM
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It works beautifully. In these times of deliberate obsolescence, I am not sure what industry, let alone brand, can boast this.
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Forum: Pentax SLR Lens Discussion
06-22-2021, 01:16 PM
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It is for APS-C, but in fact, it is also for full frame.
Just to be absolutely sure, i just tested it again with my D-FA 24-70 and my Full-frame modded DA* 60-250.
There is absolutely no vignetting visible.
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Forum: Pentax Price Watch
06-21-2021, 12:58 PM
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Both the 135mm and 14mm are out of stock just a few minutes ago. Three left of the 85mm.
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Forum: Post Your Photos!
06-19-2021, 05:08 PM
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They are from the Lens. It creates good starbursts if the right light is there. If I wish to use a plugin for Photoshop I use Pro Digital Starburst software as it is pretty good.
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Forum: Photographic Technique
06-15-2021, 06:50 PM
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Forum: Post Your Photos!
06-15-2021, 05:49 PM
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In retrospect, I am glad I only had one clear night while I was out there, since sunrise was around 0500 each day and blue hour in the evening lasted until 2100 or so. If I were up shooting the Milky Way every night, I would have had to go fully nocturnal!
Moar ISO! Also maybe more time, depending on focal length and sensor size. I like that the PhotoPills app will give you settings for your camera, focal length, and aperture for spot stars. I did find that it told me at 11mm f/2.8 on the K-3 iii I could do 15 s, but I was getting a bit of trailing so I did 13 s for my single shots. Those were at ISO 12,800 to ISO 51,200. They were definitely usable, but I had so much less noise reduction to deal with in a single exposure here.
Thanks! It’s fun to get out and play with these nice built-in features. I am not committed enough to astro to buy a tracking mount, but I will slap O-GPS1 on top of my K-3 iii and keep making shots like this.
Thanks!
Thanks! I figured I should post this since we haven’t had a lot of night sky shots from the K-3 iii at all, and this may be the first astrotracer image I’ve seen posted here at PF from the K-3 iii.
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Forum: Pentax KP
06-03-2021, 08:24 PM
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First: Thank you everyone for your replies!
Yes, my mount has a rubber gasket. There is also a metal ring under the mount. (see pic). How the mount got bent... I have no idea. I attached a couple pictures where you may be able to see the bend. Very disappointing that I or a repair shop can not just order a part!
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Forum: Photographic Technique
06-01-2021, 05:20 PM
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For an initial set up for wide field Milky Way, leave the high ISO and the long exposure noise reduction on. Turn off the auto focus. I'd start with an ISO of 1600. I'm not familiar with the D-FA 24-70 so I'd set the aperture stopped down 1 or 2 clicks (not full stops, just a click or two) from wide open. With the Astrotracer, I'd start with an exposure time of about 2 minutes. If possible, aim the camera to the South. The galactic center, the brightest part of the Milky Way, will be low in the southern sky and will rise at around 10 pm. Check the exposure. If it's overexposed, I'd decrease the ISO and try again. If underexposed, I'd increase the exposure time first and then increase the ISO if needed. The Moon will rise around 3:30 am and will be about 10% to 20% illuminated. That should illuminate the foreground without washing out the Milky Way too badly.That's a start, but be prepared to make adjustments.
For star trails, I'd start with an ISO of 800. For maximum stars you'll want the lens wide open. Turn off the high ISO and the long exposure noise reduction and auto focus. Aiming the camera north, toward the North star, will give you shorter and more curved star trails. Aiming East or West will create longer and straighter trails. If you are doing 5 minute exposures, the Moon above the horizon will wash out the sky. For star trails, I use a freeware program called Startrails. It's easy to use.
What you see in the sky won't look like the images you take. The camera captures a lot more than your eyes see. The sky glow in the center of my first image is a small city some 30 miles away. The glow isn't visible with the naked eye but shows in long exposures. As you get more practice it will get easier.
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Forum: Photographic Technique
06-01-2021, 06:29 PM
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Don't know how to multi quote, so.....
I use a Kp so don't know the K-1 II controls but they came out about the same time. On the Kp, I have a user mode set for startrails. It is based on B mode with timed shutter activated opening up the use of shutter speeds up to 20 minutes. I then have interval shooting set, minimum standby interval, all NR off. I have it set for 20 exposures of 3 minutes, ISO800 and F5.6 - but if you want to adjust this on the night, select the user mode and then change whichever settings you want - it's still much easier to remember than doing it all in one hit.
(BTW I have set up 3 user modes for night stuff - one is high ISO with NR on which I use for single exposures, composition and focus checking, the second for stacking short exposures and the third for startrails. Test them in the backyard to avoid disappointment in the field).
Don't get too hung up on ISO. Pentax use ISO invariant sensors - you can select all the images you took and push them 5 stops in post processing if you want (equiv ISO100 to 3200). ISO is only making changes AFTER the light hits your sensor - what you capture is based only on aperture and shutter speed. My approach is to stay a little on the low side as keeping control of blowing highlights (stars) is the key issue. You can also get cute in post by adjusting exposure progressively on the trails shots to get tapers on your star trails - another x-post example below:
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Forum: Photographic Technique
06-01-2021, 06:10 PM
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Exactly! In using Sequator, you simply pick a shutter speed that will be short enough not to blur stars (I use about 10 seconds with an 18 mm lens on an APS-C 24 Mp sensor). Take as many shots as you like, more is better. When you process in Sequator, there is an option to "freeze ground". You will then paint over the sky and Sequator will create a mask. In processing, it will move all the stars over the top of one another from all exposures and do a simple average on the foreground with everything fixed and spit out a result. It sounds complicated but is in fact pretty foolproof and straightforward - lots ot YT videos on it. Here's one I prepared earlier (x posted from the DA*11-18 thread):
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Forum: Photographic Technique
05-31-2021, 06:40 PM
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The k1 should easily handle an ISO of 3200 or 6400. For the Milky Way, I keep the high ISO and long exposure noise reduction on. Most lenses are soft wide open so stop the lens down stops a couple of clicks to sharpen the pinpoint stars. For a little extra stability (and for safety's sake) set a gallon jug of water under the tripod and use a bungee cord or light twine to tie the tripod to the jug of water. It will keep it from shaking in the breeze or gusts from toppling the camera and it's less likely you'll accidentally knock the camera over in the dark. Been there. Done that. It sucks. Turn off autofocus and auto exposure. I think the camera has to be in the 'B' or 'Manual' mode for Astrotracer to function. Check the instruction manual.
For star trails, I usually do five minute exposures and about a 400 ISO and stack them with Startrails program. Turn off high ISO and long exposure noise reduction. Changing exposure time won't affect the brightness or number of the star trails. It will only change how long the trails are. Lowering ISO or decreasing the aperture will decrease the number of trails and the converse is true. Higher ISO/wider aperture = more/brighter star trails.
For night photography a remote shutter release really is needed. If you don't already have on you can use the two second self timer temporarily. For star trails, an intervalometer like the Shutterboss will let you get consistent exposures longer than 30 seconds. You'll learn how hard that is to do when you start doing star trails.
The next meteor shower isn't until late July so I won't go there yet. There's more that doesn't come to mind right now but I'll try to add more as I remember it.
Oh! I know. There's a lot of post processing videos on YouTube that will help with after you get the images. just search for the keywords "Milky Way" and "post processing"
 IMGP9719 by Miles Shaylor, on Flickr
 Night_Panorama by Miles Shaylor, on Flickr
 IMGP1353 by Miles Shaylor, on Flickr
 Fort Churchill startrails 2 by Miles Shaylor, on Flickr
 Startrails2 by Miles Shaylor, on Flickr
 Startrails3 by Miles Shaylor, on Flickr
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Forum: Photographic Technique
05-31-2021, 01:28 PM
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One other tiny thing that you can do right now is to remove hot pixels, tools page 4 - pixel mapping.
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Forum: Photographic Technique
05-31-2021, 12:07 PM
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I would suggest to try some constellations as well. With an astrotrace these are very easy to do. The main issue is to locate them. But you do not have to fiddle with the foreground. Use a 50 mm or a 35 mm for a wider field of view. With the stellarium programm for pc, you can look up in advance witch constellations you will be seeing and which focal length you need.
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