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Forum: Pentax K-1 & K-1 II
03-11-2019, 10:18 PM
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Could be but would first have to find out UV test results for them.
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Forum: Pentax K-1 & K-1 II
03-10-2019, 10:13 AM
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Yes, definitely have to make sure that the corrective lens -if we need to go that route- is indeed glass and without any kind of coatings or lens cement. Both of those can cause partial or complete blocking of UV...there's a reason why there apparently zero zoom lenses that have decent UV pass through, even among the legacy oldies!
Good tips on the possible infinity issue, thanks!
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Forum: Pentax K-1 & K-1 II
03-10-2019, 01:40 AM
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Thanks! Yes, the UV focus shift is a known problem, especially with the legacy lenses that are not dedicated to UV. Not a problem with live view though. With the brute force time lapse approach this just needs to be accounted for when setting the focus before a takeoff. Perhaps that correction lens is also a possibility. I will definitely look at the WIFI commander, sounds great! Thanks!
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Forum: Pentax K-1 & K-1 II
03-09-2019, 05:18 AM
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Yes, I read about that hack. But as you say, I'd be a little hesitant to do that to a 5000-6000 euro lens :-D Furthermore those two UV-lenses that exist for the F-mount aren't the most desirable focal lengths as one is 105mm and the other is 60mm. The 60mm might do, but I rather like the idea of getting 50mm, 35mm and 21mm byt using those old legacy lenses and spending a total of circa 500 euros max. Leaves money for other stuff.
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Forum: Pentax K-1 & K-1 II
03-08-2019, 02:56 PM
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Might be easier but would be way more expensive, even with keeping the high price of this equipment in mind. We need to do these aerial scans many times, each time 72 vegetation plots of circa 2m x 3.5m so knowing a bit about their fees for just fieldwork of one day, those type of consultant companies would totally bankrupt us in no time.
SharperShape do look very professional but their service products and expertise aren't suited to our research needs. Like you said, they're more into power line mapping etc.
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Forum: Pentax K-1 & K-1 II
03-08-2019, 10:59 AM
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I suppose you did not read some of my comments?
Full spectrum conversion gives the flexibility to use UV, IR, visible light or a combination of those spectra. It is easily possible to get down to 320nm UV which is pretty good. And no, you only sacrifice the warranty, not the camera. By using lens front filters you can still take visible light images as normal.
We want to use the K-1 because it has sensor shake reduction which greatly helps with longer exposure times that are unavoidable with UV in particular, especially when it's not sunny. It is absolutely fabulous that this feature works also with the obscure legacy lenses that we will use for UV! Canon or Nikon are at a huge disadvantage there. The strong high ISO performance of K-1 will also be of great use in UV by keeping shutter times reasonable in cloudy conditions. When doing visible light or IR scans we use Pentax DFA 50mm f1.4 giving us complete weather shielding - an absolute bonus. And finally, the same camera system will also be used on a tripod on the ground, where pixel shift will be useful to have in some applications. Actually, Canon can't really hold a candle in our applications...
Finally, we intend to also use our sensors with the drone so we need the payload capability anyways. Why then choose a lighter and worse camera? We can get quite nice flying time by having 3 battery packs anyways. When the first one is depleted, it goes to charging immediately and the cycle will give us quite a bit of useful working time per day.
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Forum: Pentax K-1 & K-1 II
03-08-2019, 09:33 AM
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Thanks for the input, much appreciated!
1. I have thought of something like that, i.e. a gentle hack :-) However, let's first see what the reply and subsequent correspondence with Pentax Surveying reveals about the UP-1!
2. Yes, we are planning to use pre-programmed flight plan for the most part. It also removes any operator delay, thus saving precious flight time. A battery pack costs around 700 euros so we can't just buy ten of them :-D We'll likely get three sets as that should give a pretty good work flow (apparently takes about 90min to charge).
3. This is true. However, one of the two locations is a rather open fen with no tree canopy to obstruct. The other one is a dry pine forest but not overly dense so we'll see.
4. That's exactly what I had in mind: to use the DoF calculator for each lens being used. I also thought that at the heights we're going to use, depth of focus should be pretty good. So thanks for verifying! Depending on what legacy lenses we end up buying, we will likely use a 35mm f3.5 and a 50mm f2.8 or f4.0 for the UV shoots and Pentax new DFA 50mm f1.4 for visible light and IR scans. Yes, you are right: no AF with the UV work.
5. Most definitely! I have already started by diving into a few oases of information on UV:
35 mm lenses for UV
Ultraviolet Photography
Both sites contain a wealth of information and links!
I will definitely keep updating this thread as we progress :-) It will take months just to make the choices, purchase equipment and assemble it. But hopefully some time in the summer we will start the actual work!
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Forum: Pentax K-1 & K-1 II
03-08-2019, 02:45 AM
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A balloon might be useful for some light applications and would definitely be very cheap. However, it would be terribly difficult, if not impossible, to control satisfactorily. We ruled balloons out at the very start of our considerations.
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Forum: Pentax K-1 & K-1 II
03-08-2019, 01:59 AM
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Time lapse is one option that we have considered but it is not optimal as we need to get low aerials of a very large number of vegetation plot that are part of a long-term manipulative field experiment. With manual, legacy lenses in use, would also need to calculate focal distance (i.e. drone height --> distance from lens to the ground) carefully before taking off and setting the lens focus plane so that the resulting images would be in focus.
I just put in an inquiry on the UP-1 drone combo to Pentax Surveying. Let's see what the answers are!
I am also aware that there are high-quality wired power tethering options for this drone. They use a light power wire and high input voltage (due to resistance, to reach the desired 12V at the drone). These enable unlimited flight time and would be of interest as well, because we intend to fly not just the camera but also NDVI sensors and radiometers/pyranometers. But these drone power tethering systems cost around 5000 to 10 000 euros so we'll have to consider our priorities,
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Forum: Pentax K-1 & K-1 II
03-07-2019, 10:23 PM
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Thanks for the great responses! The gimbal would be the Ronin MX. In terms of control needs, we need live view and the camera controls provided by Image Sync so a remote trigger is not enough. Live View is especially important because we will be also doing UV photography and for that we will need to use full manual legacy lenses (there are several with good enough UV pass through.
The dedicated UV lenses by Coastal Optics and Nikon are not an option. Not so much because of the high price but because of those being available only for Nikon F. So there would be no infinity focus without an adapter that has corrective optics...and those optics would not pass UV (almost certainly). So we're going to use a few different fixed focal length m42 lenses. A mix of the oldest tech and the newest possible! I like that :)
One thing in UV photography is the rather long exposure times (unless full and strong direct sunlight) even with UV-capable lenses and that is where the high ISO capabilities of the K-1 will be important but even more so the sensor shake reduction of course. For visible light and IR stuff we of course appreciate the weather shielding of the Pentax and it's lenses (the new 50mm f1.4 will be the most important lens for us).
I did not know that Pentax surveying is already selling a combo of Pentax K-1 and this drone! I must look into the pricing and functionality. Perhaps it is good alternative.
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Forum: Pentax K-1 & K-1 II
03-07-2019, 03:10 PM
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Yes, this one: Matrice 600 -*Simply Professional Performance
It has a payload capability of roughly 6kg, of which the gimbal takes 1,5kg. Still plenty left for a K-1 and a lens :)
I am also planning to do UV and IR with it, so the camera will immediately go to be modded for that (full spectrum conversion). This voids the warranty, but that's ok.
As you maybe guessed, this setup is for research purposes.
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Forum: Pentax K-1 & K-1 II
03-07-2019, 02:32 PM
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Hi,
Apologies if this has been dealt with already but what is the operational range (outdoors) of the wifi tethering of K-1? I am planning to do photography using a drone so this is quite crucial. I do not care about image transfer, just controlling the camera.
Thanks for any info/experiences!
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