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Forum: Pentax K-3 III 3 Days Ago  
Using K-3iii astrotracer type 3
Posted By MossyRocks
Replies: 4
Views: 446
I have tried it with lenses as short as 28mm and type 3 works fine even in my very badly light polluted backyard which is a bortle 8 location for light pollution with a 9 about a mile away. If you want to find out how bad your location is you can check it here. I even tried shooting with the full moon just out of the frame and it was able to find enough stars to calculate tracking. From what I have experienced, type 3 will fail to track if the stars get too big like what happens when you are out and the lens gets fogged, or your focus is off. My guess is that unless you manually focused with a bahtinov mask or really fiddled around in magnified live view looking to turn on the dim stars that will flicker if focus isn't perfect your problem was that the focus was off by a bit. With astrotracer it works better for longer lenses as they have a narrower field of view so the movement throught the frame is more similar. Once one gets much shorter than 28mm the corners start suffering as the difference in movement from the center of the frame to the corners is just too different and you get streaking. That isn't to say you can't use it to extend your exposure time beyond the good rule of 200 (200/focal length) but I haven't done that. I should try that out and see if I can get a good 40s exposure with my 12mm as that would double the exposure time.
Forum: Pentax SLR Lens Discussion 3 Days Ago  
Comparison between the old and new 100mm macros. Contains many large images
Posted By MossyRocks
Replies: 15
Views: 995
Cold is one of the best times. You get those very cold clear nights with next to no humidity and great sky clarity. If you have the right gear it isn't bad but then I look like the Michelin Man when out doing winter astrophotography.
Forum: Pentax SLR Lens Discussion 3 Days Ago  
tested five glasses on "ultra wide - close ups" and the results were WEIRD !!!
Posted By MossyRocks
Replies: 26
Views: 977
And this gets to the subjectivity of lenses. I had that lens and hated it. I would try and use it but it just never clicked and I never cared for the rendering. Instead I saw that my local camera shop had the K 35/2 so I sold the DA 35/2.4 to them and got the K 35/2 as it wasn't terribly expensive. Turns out I actually really like the K 35/2 and frequently use it. Then last weekend I needed a new to me 50/1.4 (kids likely knocked one of mine off the shelf and stepped on it is my guess for the damage) and happened to see that they had the DA 35/2.8 Macro Limited and figured why not get that also. it is weird for me to be using a wider lens not at infinity but so far I like it enough to still want to play with it more. I figure if I don't like it I can always sell it and not be out much if anything and then get something different to play with.
Forum: Pentax SLR Lens Discussion 3 Days Ago  
Comparison between the old and new 100mm macros. Contains many large images
Posted By MossyRocks
Replies: 15
Views: 995
I suggest you lend the lens to me for a week or so and I can go really put it through its paces and stick it on my equatorial and shoot some ultra high contrast point light sources some night.

In all seriousness I am considering getting this lens as the purple fringing problem really has been resolved so it may be a good performer for astro but would like to see some controlled shots.
Forum: Pentax K-3 III 11-22-2022, 12:20 PM  
Using K-3iii astrotracer type 3
Posted By MossyRocks
Replies: 4
Views: 446
Having used it a fair amount some ground can be in the image but generally try to avoid it if possible. Also from using it it really needs you to have a good focus, proper focal length entered, a non fogged lens, and don't have a gigantic object in the frame. I have had all of those problems some were deliberate in trying to figure it out and trying to figure out what causes the "data processing error", others were just happenstance things. The bad focus and fogged lens were things I discovered by accident, apparently it really struggles with really bloated stars that result in the test shot or shots (still don't know). The gigantic object was when I tried it with a full moon in the frame at 800mm and was part of my figure it out testing. Same thing with inaccurate focal length. Surprisingly it will pick out stars even in very heavy light pollution and can figure out how to track them. I tested this when doing my test shots in my bright bortle 8 backyard with my 400mm lens with the full moon just out of the frame and it found stars no problem and tracked them.

Usually when I shoot landscapes or night scenes with a foreground I am running a wide to ultrawide lens and there I just ride the rule of 200 for my exposure time (200 / focal length=exposure time in seconds). From there I take a pile of images and will stack them in software like Sequator which can freeze the ground and the sky.
Forum: Pentax News and Rumors 11-18-2022, 03:14 PM  
HD Pentax‐D FA Macro 100mm f/2.8 ED AW
Posted By MossyRocks
Replies: 195
Views: 16,763
Given that the type of fringing I always got was the purple with the now old SMC D FA 100/2.8 WR Macro the lack of it in the shot you provided would lead one to believe that it would be a good performer for astro. Also I would agree that it may be a bit sharper wide open from your test shots which again bodes well for astro.
Forum: Pentax News and Rumors 11-17-2022, 02:26 PM  
HD Pentax‐D FA Macro 100mm f/2.8 ED AW
Posted By MossyRocks
Replies: 195
Views: 16,763
That is what I am wondering too. However I still like my D FA 100/2.8 WR Macro and even made use of the WR feature last week getting shots of an angry Lake Superior. I will probably get one as it looks like it isn't too expensive (still more than a impulse buy but that doesn't mean I can't save up for a bit).
Forum: Pentax K-1 & K-1 II 11-15-2022, 12:31 PM  
Some beginners questions regarding Astrotracer and INT shooting :-)
Posted By MossyRocks
Replies: 17
Views: 947
The infinity mark is rarely where true infinity is. I have had to adjust almost all my lenses as most got really close but didn't make it. So now they all focus slightly beyond infinity.



Preference really does make a difference for keeping a lens or not. Not having the the 43ltd I have no idea how it does with astro shooting but in taking a wild guess I would think it may get to astro good at the same f/2.8 as the FA 50/1.4 but that is just a guess.
Forum: Pentax K-3 III 11-15-2022, 09:32 AM  
K3III With a Telescope?
Posted By MossyRocks
Replies: 11
Views: 694
That sounds like a good tripod so you have that covered.
Forum: Pentax K-3 III 11-03-2022, 01:34 PM  
K3III With a Telescope?
Posted By MossyRocks
Replies: 11
Views: 694
Actually I am not using that lens. I am using the even faster SMC A* 400mm F/2.8 which is a regular (exceptional quality though) full frame K-mount lens. A 300mm f/4 lens would be a good starter lens or even one of the old Pentax 200mm f/4 lenses. The 300mm I have is the Sigma 300mm F/4 APO Tele Macro and I got it from my local camera shop at the stole it price of $130. When I suggest one of the old 200mm F/4 lenses I do mean old. I have and use the M42 mount SMC 200mm F/4 Takumar and I know others have used the M and A versions as well and those lenses really want to be run at F/5.6. I can usually find one locally for between $60 and $90 dollars in optically great condition with varying features and wear on the lens barrel. Lenses like a good 200mm or 300mm will open up a lot of good starter deep sky objects. Also if you want wider get one of the old Pentax 50/1.4 lenses, I run the M42 mount SMC 50/1.4 Takumar and like basically all the Pentax 50s it really wants to be run at F/2.8 for astro. Again old ones work just as well as newer ones and can be had for less than $100 in good shape. Wider and cheaper still you could get the old M42 mount SMC 28mm F/3.5 Takumar and for astro it gets great at f/4 and mine I got for $80 but it also had the case for it, the hood, and the hood case but was also basically immaculate.

Apart from the A* 400/2.8 the lenses I've mentioned above are not exceptional, are not hard to find, and are not expensive.

My other bit of advise is to get the biggest heaviest tripod you can find. My biggest one is this wooden monster but that is probably overkill however it only cost me $50 and an afternoon with some power tools. The other tripod I use for astro is an old Manfrotto 3058 tripod with the Manfrotto 3057 head that I picked up for $110. For astro you really want big, heavy, and ridged as that minimized vibration and quickly dampens it.
Forum: Pentax K-3 III 11-02-2022, 01:59 PM  
K3III With a Telescope?
Posted By MossyRocks
Replies: 11
Views: 694
As far as where to start go join the Astrophotogrophy group. We are a friendly lot and are pretty good about answering questions and providing feedback and tips.

To get a scope or not for astrophotography is something I would advise against for a beginner. There is a lot to learn and mast starting out without having to fiddle around with the narrow view and likely dim view that a scope would offer. There are lots of things that can be photographed nicely with lenses in the 200mm to 400mm range on an APS-C format camera. Orion is coming into prime time now, the Plieades too. There is also stuff in Cassiopeia. Prime lenses are king and even wide stuff like a 28mm, 35mm, 12mm can produce some great results. If you want some idea of what different lenses can show I have an astro album and other post shots in the astro group frequently.
Forum: Pentax K-3 III 11-02-2022, 08:46 AM  
K3III With a Telescope?
Posted By MossyRocks
Replies: 11
Views: 694
That is really the key thing but as mentioned tracking time gets lower with longer lenses/scopes.



I usually don't shoot night landscapes with astrotracer (type 3) so have never tried it. I likely would do it but again the shot would mostly be sky. If the moon is in the frame it really struggles probably because of the gigantic bright round thing in the sky. I did that when I was trying to figure out how and why it fails and was using my 200mm and 300mm lenses. Type 3 astrotracer seems to be pretty good at picking out stars as with the full moon just out of the frame in my heavily light polluted backyard it still managed to find stars and correctly calculate how to track.
Forum: Pentax K-1 & K-1 II 11-02-2022, 08:41 AM  
Some beginners questions regarding Astrotracer and INT shooting :-)
Posted By MossyRocks
Replies: 17
Views: 947
All of the Pentax 50/1.4 lenses with the exception of the D FA* 50/1.4 seem to be that way and even the DFA*50/1.4 still struggles a lot with astro wide open. However the sample shot from above looks softer than it should be even for astro shooting and more like the focus was missed slightly.
Forum: Pentax K-01 11-01-2022, 02:52 PM  
Sigma can, why can't Pentax?
Posted By MossyRocks
Replies: 141
Views: 3,984
That actually surprises me in the how can they be that small way.
Forum: Pentax K-1 & K-1 II 11-01-2022, 02:30 PM  
Some beginners questions regarding Astrotracer and INT shooting :-)
Posted By MossyRocks
Replies: 17
Views: 947
Don't bother with interval shooting for star trails. My advise is use a 30s shutter speed and then set you f-stop and ISO to get what you want. Basically take a test shot and decide if you have too many stars or not enough. Then put it into continuous high speed drive mode and let it run until the battery dies, you get sick of being out, or you think they have moved enough. The high speed continuous drive mode won't allow enough movement of the stars from one shot to another to allow a gap to appear. If deliberately going for star trails 30s minimizes the number of shots but if you are in a spot where people might result in a bad frame because of a brief opps (excess light because lots of people are really bad at managing their light) going with a shorter shot length but still doing continuous high speed shooting should result in being able to drop the odd sing bad frame here or there without losing the nice continuous trails. For figuring that out you want to use a shutter speed half of what the rule of 200 would give you, so a shutter speed in seconds of 100/focal length.



My best guess is that the focus shifted slightly and that papered over the jaggedness of the interval shooting that was showing up in the early shots.

In looking at the shot you took with the FA 50/1.4 there is a lot of bloating of stars and what appears to be some pretty bad coma. I wonder if you missed the focus slightly as that will make these things worse. My experience, and others, is that the Pentax 50mm lenses basically peak for astro at f/2.8 and clean up pretty good at that point with only some minor coma in the corners. This seems to hold for my M42 SMC 50/1.4 Takumar , A 50/1.2, and M 50/1.7 and I believe others have used the FA 50/1.4 and even the new D FA* 50/1.4 with similar results. Nailing the focus really is key and I would suggest getting a bahtinov mask with very find spacing. I have one that is fine enough to work down to a lens with a 28mm focal length.


If you didn't move the camera then recalibrating shouldn't be needed. By move the camera I don't mean move it around on the tripod but actually move the location of the tripod it is sitting on. Checking and adjusting the focus is usually needed as time progresses because the focus will shift slightly as things cool down and as the night get cooler. The longer the lens the more this is needed. I try to have my lenses out coming to the ambient temp while I get everything else setup and is really critical for my 400mm as that thing takes a long time to come to temp.
Forum: Pentax K-3 III 11-01-2022, 02:01 PM  
K3III With a Telescope?
Posted By MossyRocks
Replies: 11
Views: 694
Astrotracer with a telescope will be problematic. I have long used it with my 400mm lens (A* 400/2.8) and for GPS based astrotracer I can consistently get good 20s shots. With the K-3iii and type 3 astrotracer I can get consistent 40s shots. The various incarnations of astrotracer basically require good focal length data which is one of the limiting factors. Also type 3 really needs a good focus otherwise it gets confused and fails to process the test shot or shots (still haven't figured out how that works entirely). When you increase focal length you decrease the tracking time for good shots. So if you are out near 800mm (like most inexpensive scopes) I would expect you could get 20s shots. However most scopes aren't as bright as my 400/2.8 unless they are one of the mirror ones but those typically have substantally longer focal lengths.
Forum: Pentax K-3 III 10-28-2022, 08:35 AM  
SD Cards Pentax K3 III for Antarctica & Camera Shutter Won't Work
Posted By MossyRocks
Replies: 10
Views: 702
That is just a recommendation. I've run regular fast SanDisk cards (not the weather/environment hardened ones) in temps down to -25F for extended periods and not had problems. Although now I do wonder if abuse like that is significantly shortening their life but I think the huge piles of astro shots probably does more damage to them overall. Usually temp ranges like that mean one can expect the card to perform perfectly normal but when you get outside of it then you might experience strangeness. A little to either side shouldn't be an issue but if I was out shooting at -40 or colder I would expect issues unless I have done that before and had experience. Now I want to go shoot Split Rock Lighthouse in the winter some time at night.
Forum: Pentax KP 10-28-2022, 08:14 AM  
The KP shoot that didnít happen
Posted By MossyRocks
Replies: 29
Views: 1,369
I shouldn't laugh but I do because I've done that as well. So it is a laugh of sympathy.

Although you at least brought the camera. Early this past summer I went out to shoot the Milky Way over the Frank Schott old stone barn as I really wanted to see how the K-3iii did with untracked ultrawide astro shots and drove all the way out there (3.5 hours) started getting stuff setup up and then realized I left the camera by the door at home. It was a perfect clear dry moonless night I had my 2 biggest tripods, my little equatorial, the K-3 and K-3ii and a sack full of lenses but didn't have the K-3iii or my Laowa 12mm.


I should do this. It isn't like they take up much real space or weight.
Forum: Pentax K-3 III 10-27-2022, 02:31 PM  
SD Cards Pentax K3 III for Antarctica & Camera Shutter Won't Work
Posted By MossyRocks
Replies: 10
Views: 702
Batteries come back to life when warmed back up but only having one battery would mean waiting for that one to warm up. So having 2 or 3 should allow mostly uninterrupted shooting. Also going to Antarctic is done during the Antarctic summer and while it isn't exactly warm the temps are no where too extreme. I actually looked it up and in November it is around 20F so while cold for someone in San Francisco that would be a nice warm winter day in MN really requiring just a lined sweatshirt. It looks like in January it gets into the low 40s so rather warm and for someone who gets accustomed to the cold the first 40 degree day becomes t-shirt weather. So given those temps frozen batteries won't be much of a problem.
Forum: Pentax K-3 III 10-27-2022, 11:16 AM  
SD Cards Pentax K3 III for Antarctica & Camera Shutter Won't Work
Posted By MossyRocks
Replies: 10
Views: 702
I wouldn't worry about having one of the extreme cards. However I would want lots of cards and would be looking to have them be setup for redundant write for a trip like this. I run my K-3iii as well as my other cameras in colder weather than you will experience there with the better SanDisk cards and apart from wearing a few of them out, shooting many hundreds to a thousand shots per camera in a single night of astro shooting will do that, haven't had any issues. I've been out in temps around -25F with the camera bodies and tripods getting frosted up for extended periods so I do like to punish my equipment.

I wonder if your problem with it not taking a shot is that it isn't releasing because it doesn't believe it has focus.
Forum: Pentax K-1 & K-1 II 10-26-2022, 08:55 AM  
Some beginners questions regarding Astrotracer and INT shooting :-)
Posted By MossyRocks
Replies: 17
Views: 947
As others have stated you have dark frame subtraction turned on. For astro shooting the general advise it to turn it off and if you want to do dark fram subtraction shoot your own dark frames (shoot a bunch) at the end of a session at the same ISO and shutter speed. There are tools that will combine the collected dark frames will using averaging to produce a master dark frame that will be subtracted. A master dark frame made from several darks will be a more accurate representation of the systematic error you are trying to remove from each light as the true random noise will be driven down substantally. This also better preservers the actual data in each of the light frames. I can go into a more detailed explanation if desired but won't at this point.

As far as the dotted lines/trails you are seeing in your final image that is because of the interval mode with additive selected. After each shot astrotracer will reset the sensor position and begin tracking the sky again so the framing is slightly different between each shot. Depending on what you are after the best solution is likely to just shoot a pile of light frames (shoot the darks while you pack up) and then combine them in post processing. There are a bunch of tools available here depending on what you are after. If it is just the night sky there are programs like Deep Sky Stacker (DSS), Astro Pixel Processor (APP), Pixel Insight (PI), Sequator, Siril, and probably others that I am unaware of. These will align images based off of star patterns and then either do some fancy match from simple averages to sigma clipped means and others, I also believe that some will also add the aligned frames together like what you are trying to do in camera. If it is a shot of the foreground landscape with the night sky then you really want to use Sequator as it has a feature to freeze the ground and also freeze the sky. Astrotracer can produce some great results even with huge lenses.

When I chase Deep Sky Objects (DSOs) I will use astrotracer with an intervolometer (functions like an interval mode shooting but likely with more options) but you are collecting individual light frames so not in camera averaging, addition, etc. After a few shots (depending on location and linear speed) I will reframe on the object and let the intervolometer take some more shots for me. I also shoot untracked with wides and ultra wides (photography wide and ultrawide astronomy used very different definitions) and use the rule of 200 for each shot (200/focal length= exposure time in seconds). There I will put the camera into the high speed continous drive mode and use a remote release cable with the button pressed (I made my own with a toggle switch) and just let the camera roll. Then I combine all the images in post processing.

A Deep Sky Object shot with my 400mm lens, K-3, and O-GPS1 for astrotracer with almost 9 hours worth of shots:


A night landscape shot taken untracked with my 12mm lens, K-3ii, Vivitar 285HV speed light at 1/16 power and diffuser with about 10 minutes of shots:
Forum: Film SLRs and Compact Film Cameras 10-24-2022, 01:19 PM  
K1000 - What's the Appeal?
Posted By MossyRocks
Replies: 66
Views: 2,195
I would have to agree that for a lot of people it is nostalgia as they likely learned on a K1000 or that is what they aspired to get when starting out way back when. I still hear people refer to them as a "professional" camera when referring to owning one years ago or learning on one years ago back in school. When I am at my local camera store and trying out a lens and didn't bring my digital they always hand me a K1000 to try it out with even though they usually have a few KX, MX, or sometimes LX bodies that it could be stuck on instead where one can really see if the lens is functional (DoF preview being the most notable and sluggishness in the aperture). Also like others have noted even a beat up K1000 will go for a higher price than a pristine KX or MX and a nice K1000 will come in just below a LX or at least they do at my local camera store.

I love my old Spotmatic F and that was my first "real" camera and what I learned on. It is really beat to hell (a good amount of brassing, several dents, some paint chips, and a lot of scuffs) but just keeps going. If I didn't already own another one (pristine condition) I would consider getting one just because I like it.
Forum: Troubleshooting and Beginner Help 10-19-2022, 10:51 AM  
O-GPS1 calibration on K70 versus K3II internal gps.
Posted By MossyRocks
Replies: 11
Views: 518
That doesn't surprise me. The IBIS in each has magnets and there would be various powered up electronic components in them. Then there is the shutter and mirror mechanisms so them interfering with each other shouldn't be a surprise.

Off by 1ish degrees should generally result in good tracking at reasonable times assuming everything else is good. I have actually given up on GPS based astrotracer with the K-3iii as type 3 astrotracer is a lot better. My K-3 and K-3ii now ride around on my little equatorial with one acting as the counterweight for the other (because I can and it works).when I still used type 1 (GPS based) astrotracer I would have that camera on my big wooden tripod well away from the bodies on the equatorial sitting on the Manfrotto 3058 tripod as that setup would interfear with the stepper motor and everything else.
Forum: Troubleshooting and Beginner Help 10-18-2022, 12:13 PM  
O-GPS1 calibration on K70 versus K3II internal gps.
Posted By MossyRocks
Replies: 11
Views: 518
This is going to be a problem for tracking. Look for things that have magnetic fields (electricity flowing) or sources of iron. Both will throw the compass off. Things like fence posts, vehicles, reinforced concrete, buried power lines, overhead power lines, electric motors, steel bits in your tripod, excess iron in the soil (a problem in norther MN), etc. have all cause me problems in the past.
Forum: Pentax K-3 III 10-18-2022, 12:06 PM  
Astrotracer question
Posted By MossyRocks
Replies: 11
Views: 730
For astrostacking Deep Sky Stacker (DSS), Astro Pixel Processor (APP), and Sequator I know all do it and have used that feature in them. Pixel Insight (PI) also has that functionality but I haven't used it and I believe that Siril also does it but I haven't used that software either. I have also seen master dark creation and dark frame subtraction functionality in RawTherapee but haven't ever used it.
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