[leonine]

The AF is probably too slow for shots from a moving vehicle - I know this is true for my copy. It's not bad to manually focus.

I plan to keep the lens focussed on infinity permanently in manual mode. So this should not be an issue.

---------- Post added 05-24-21 at 09:21 PM ----------

This has not been proven in images. As you are in an airborne moving vehicle, you will need substantial shutter speed for clarity in your shot, so you will need higher ISO regardless. Any of the vintage lenses can produce green or purple fringing in high contrast situations. I have often used the FA 77mm for night shots, or just after sunset with fine results. Just lucky, I guess. But with a 50mm lens on your K-1, you will get much more in your shot than with the FA 77m lens. The "F" or "FA" 50mm f/1.7 is pretty good wide open and yet better at f/2, better-performing than the FA 50mm f/1.4 at these larger apertures. You might even consider a DA 40mm lens wide open, if available. You can of course run test shots at night when on the ground.

Thank you. The saving grace is that the IBIS of K1 is excellent. I could get reasonably sharp images even at 1/90 sec with FA 77mm at f1.8 with ISO at 12800. I need to get at least one stop extra, preferably two, so that I can get the ISO down to 6400 max and maybe the shutter speed up at about 1/150 or so. That would be pretty good I think.

FA 77mm is a joy to use and the images are sharp when everything like shutter speed, chopper vibrations and luck falls in place. But the purple fringing around every single big point source of light is just ghastly. I have shot from air twice already. The images would need a great amount of tedious PP to get rid of all that purple unless someone knows how to handle it in a few clicks. I don't. In fact I am just average in PP. Perhaps I should find an expert to do this for me.

---------- Post added 05-24-21 at 09:27 PM ----------

It may not be helpful but I have A 50 f1.2 and the FA 50 f1.4 and from my experience these lenses are not their best wide open and infinity and better focusing wide open on subjects say < 10m.
However that said my A 50 f1.2 seems to be say a stop better than FA 50 over the range of f1.4 - f4. By that I mean if I stop down the A 50 to f1.4 the IQ is more like the FA 50 at f2 (and in fact I quite often use the A 50 at f1.4 when I'm looking for better sharpness). Still probably not enough for you at infinity though.

Thank you. This is somewhat encouraging. I will try out the A 50mm at f1.4 and f1.8 when I get it hopefully next month.

I wonder if some of the AI based software could tackle the softness issue at infinity.

---------- Post added 05-24-21 at 09:36 PM ----------

Photons to photos does show a dynamic range advantage for the k3iii over the k-1ii the difference is at iso 12800 about a half stop. The k-1ii is about 1 full stop better than the k-1 at that same iso. This isn’t consistent across the board and at base iso the k-1 models outperform the k3iii. Put another way. At iso 12800 the k3iii should perform like the original k-1 set to iso 4000 or so as far as dynamic range is concerned.

With that in mind a 1.5 stop gain in dynamic range is very nice but the iso may still need to go up farther to get the shot.

I haven't seen any real world reviews of high ISO performance of the K3iii, or its comparison with the K1 or K1ii. But from what I have gathered, including in an interaction with a Pentax Ambassador, is that despite being an APSC sensor, the K3 iii is better at high ISO than the K1 ii and certainly the K1.

So if ISO 12800 on the K3iii is as good as ISO 4000 on K1, that's fantastic news for me, under the present circumstances Of course, the shadows can simply be absolutely dark. It is the lit portions of the city (roads, buildings etc) and the patterns they exhibit when seen from the air that matter. If the noise at ISO 12800 is better for K3iii, it would be excellent because I will get one extra stop to play with.

---------- Post added 05-24-21 at 09:42 PM ----------

f/1,2 and f/1,4 lenses from the past era aren't built to have sharpness wide open... above all in the borders

Thanks Andrea. Looks like the film era lenses are a non-starter for this application. I will need to concentrate on one of the latest Pentax DFA* 50mm or Sigma 35mm f1.4.

---------- Post added 05-24-21 at 09:53 PM ----------

I gave it a quick try yesterday night with my FA50/1.4 (have the K50/1.2, but did not try it ).
Assumed the settings TAv mode, 1/250, f1.4
The so called infinity for my lens wasn't even acceptably sharp (it may vary copy to copy; but I would say don't assume what you have is better (best to try it beforehand ) )
ISO was something like 20K on that setting (can be 12K if exposure -ve compensating for the shadows )
f2 is probably acceptable for smaller images and infinity focus seems correct.
f2.8 and ISO was a bit too high imho vs f2 (so the lens got sharper, but the grain went up to a point that I feel ended up to be worse )

Remember, I am assuming 1/250 and not compensating for shadows.
If you do both (eg. -1ev, 1/125, you get back 2 stops which can go to f-stop and/or ISO )

Thank you. It's the eternal struggle between stopping down to make images sharper and reducing effects of lens aberrations versus getting grainy images at high ISOs. Some sort of golden mean needs to be found where the images are acceptable if not the best that they could be. The only other alternative is to get a Fujifilm 100 with their 80mm f1.7 and mount it on a suitable Kenyon Gyro. Unfortunately, that is neither possible under the present circumstances nor is it the most cost effective solution.

1/125 sec on a digital camera with 5+ stop IBIS at ISO 12800 and f1.4/ f1.2 on a modern digital lens with advanced optical design and coatings seems to be emerging as the Go To solution.

---------- Post added 05-24-21 at 10:06 PM ----------

If sharpness wide open is important (and I guess in this situation it is), the Sigma 35/1.4 Art or the DFA* 50/1.4 will suit you perfectly.

The Sigma is much cheaper, as well as giving you a wider field of view.

I also have both the FA 50/1.4 and A 50/1.2, and neither would be my choice for this assignment. Softness wide open, relatively poor edges, and chromatic aberration are all significant minuses.

Thanks Sandy. Looks like the Sigma 35mm f1.4 Art on K3iii is the best possible compromise, with effective field of view of 52mm on full frame. It will certainly be better than my present combination of K1 with FA 77mm f1.8, and should give me around 1.5 stops advantage, which I can use up on reducing the ISO or increasing the shutter speed. A lot depends on the ambient wind conditions on the day of shooting. I have experienced days when there are no air currents and an experienced pilot can glide the chopper with minimum vibrations. Those are the best of times and one needs a certain amount of luck for those times

Unfortunately the guys using the images haven't allowed me to display the aerial images anywhere for now. I would love to share some of those on this forum as soon as they allow me to.

[pinholecam]

Seems like f2.8 should work...

9 Photography Tips When Photographing Cityscapes from a Helicopter | Fstoppers

[UncleVanya]

Unfortunately the guys using the images haven't allowed me to display the aerial images anywhere for now. I would love to share some of those on this forum as soon as they allow me to.

Will they allow a small crop?

[madbrain]

f/1,2 and f/1,4 lenses from the past era aren't built to have sharpness wide open... above all in the borders

Which lens was that taken from ? On a film body I would assume ?
My FA50/1.4 performs significantly better wide open at close focus. Have not tested it at infinity focus like the OP needs.
It's not the fastest autofocus lens, though.

[leonine]

Will they allow a small crop?

I hadn't thought of that. I think a small crop shouldn't be a problem. I will revert.

---------- Post added 05-26-21 at 12:28 AM ----------

This is a tricky project. Open door single engine chopper of 1960s vintage, edgy pilots due to small margins of error in flying, tied to a seat belt (I am going to ask for a harness in next sortie which will allow me to move a bit to the left and right)... winds buffeting you in the rear seat and lot of restrictions on height to maintain and how close you can get to the areas of interest.

The last thing one can do here is to compromise on the equipment sans the Gyro.

If the K3iii doesn't come in next two weeks due to travel restrictions, I don't think I have a choice but to maybe pick up the Sony A7 iii and Sigma 35mm f1.2, which are thankfully available to buy but not to rent.

I just hope all this trouble gives at least 1.5 to 2 effective f-stops to play with, while also reducing the purple fringing.

I also face a silly problem. I use reading glasses and need them to check the results of what I am shooting on the camera LCD screen at least a few times if not regularly. However, I need to remove the glasses when I am actually shooting. And things change so dramatically when you are flying in a chopper due to the sudden gusts of wind, chopper vibrations etc that one needs to change the shutter speed regularly to keep pace with the changes in ambient environmental conditions, specifically during the night. Now, you would want to check out the images once at least particularly after you change the camera settings. So you need to put on the glasses again. But this putting on and taking off of glasses (or anything else from anywhere including your pockets or your bag) is considered a flight safety hazard and is not normally allowed. You can keep the glasses dangling with a neck strap around your neck but then it fouls with the safety jacket appendages (because we also fly over the sea) and the two cameras dangling around your neck and the RT set (headphones). Gets pretty crazy at times particularly when things get entangled. The last time the K1 neck strap actually came off due to a wind gust just as I was switching over to the 645Z, and I almost dropped the K1 out of the chopper. Very disconcerting and risky specifically in the night. Such falling objects have been known to damage the tail rotor of the chopper with disastrous consequences.

Can anyone suggest a solution to this conundrum of using glasses in such situation? The permanent solution is perhaps to get the eyes fixed through a laser surgery

[Andrea K]

Which lens was that taken from ? On a film body I would assume ?
My FA50/1.4 performs significantly better wide open at close focus. Have not tested it at infinity focus like the OP needs.
It's not the fastest autofocus lens, though.

Was a (not mine) K f/1,2 at minimum focus distance, camera was an MX and the film was the Ilford HP5 plus 400 ISO.
The shot is to demonstrate the field curvature, not the sharpness.

[leonine]

Some more questions friends :-

1. If an image is otherwise sharp (no blur), what are the best print sizes for night cityscape images from K1 at 6400, 9000, 12800, 18000 & 25600. I just want approx idea, not very precise answers.

2. With AI coming in PP in a big way, are there any advanced software specifically meant to handle high ISO images with very big DR like night cityscapes?

3. Are there any services anywhere which can do the advanced PP for you for max noise reduction, maybe with proprietary algorithms and in-house skills?

[UncleVanya]

With respect to the Sony A7iii the on paper delta from photons to photos vs a plain K-1 is a around 1.5 stops at the iso you have been discussing (target of 12800 or so). However, Sony ibis has more limitations than Pentax from what I have read. Here’s a very lightweight explanation in a thread: Why Can't Sony Make IBIS that keeps up with competitors? - FM Forums essentially the theory is that Sony’s travel on their ibis is more limited than some of their competitors. The theory suggests that Sony is good at smaller jittering than larger movements. So for this flight there might be surprises (positive or negative) given the level of motion you have described.

As to your problem with glasses, can you arrange to mount a laptop or other larger screen to view the images on? Is the problem with wearing the glasses simply seeing the edges of the frame through the viewfinder or is it more of a close focus issue? Does live view work any better? Could you wear contacts?

[UncleVanya]

I also meant to suggest adding a safety to your existing straps. If the tripod socket is free add an additional anchor point on the cameras and attach a safety line tether to them. They might break free of the straps but adding an additional line wouldn’t hurt. You may need to use a non permanent thread locker to keep the anchor in place.

[leonine]

With respect to the Sony A7iii the on paper delta from photons to photos vs a plain K-1 is a around 1.5 stops at the iso you have been discussing (target of 12800 or so). However, Sony ibis has more limitations than Pentax from what I have read. Here’s a very lightweight explanation in a thread: Why Can't Sony Make IBIS that keeps up with competitors? - FM Forums essentially the theory is that Sony’s travel on their ibis is more limited than some of their competitors. The theory suggests that Sony is good at smaller jittering than larger movements. So for this flight there might be surprises (positive or negative) given the level of motion you have described.

As to your problem with glasses, can you arrange to mount a laptop or other larger screen to view the images on? Is the problem with wearing the glasses simply seeing the edges of the frame through the viewfinder or is it more of a close focus issue? Does live view work any better? Could you wear contacts?

There are many intangibles and no straight answers. What I have been told by people who have used the Sony A7 iii is that it is really great at high ISOs. Whether the IBIS negates the inherent high ISO performance advantage might have to be seen by using it in the field. I will try it out and revert to the forum.

I prefer OVF to Liveview because I feel more connected and in control with the OVF. Contacts I haven't tried. A progressive lens spectacles is a good option. I will try it out the next time I fly. Rigging up a laptop is ruled out. I can also try out shifting the glasses down the bridge of my nose and then look into the OVF from above the edge of the glasses but look into the LCD through the glasses. Not very comfortable but doable.

Oh the price one pays for getting old... You see things better but not clearly enough

---------- Post added 05-27-21 at 09:10 AM ----------

I also meant to suggest adding a safety to your existing straps. If the tripod socket is free add an additional anchor point on the cameras and attach a safety line tether to them. They might break free of the straps but adding an additional line wouldn’t hurt. You may need to use a non permanent thread locker to keep the anchor in place.

Thanks for the valid suggestion. No amount of extra care is too much when it comes to flight safety.

[UncleVanya]

There are many intangibles and no straight answers. What I have been told by people who have used the Sony A7 iii is that it is really great at high ISOs. Whether the IBIS negates the inherent high ISO performance advantage might have to be seen by using it in the field. I will try it out and revert to the forum.

I prefer OVF to Liveview because I feel more connected and in control with the OVF. Contacts I haven't tried. A progressive lens spectacles is a good option. I will try it out the next time I fly. Rigging up a laptop is ruled out. I can also try out shifting the glasses down the bridge of my nose and then look into the OVF from above the edge of the glasses but look into the LCD through the glasses. Not very comfortable but doable.

Oh the price one pays for getting old... You see things better but not clearly enough

---------- Post added 05-27-21 at 09:10 AM ----------



Thanks for the valid suggestion. No amount of extra care is too much when it comes to flight safety.

I use progressives myself. They were hard to initially adjust to but not bad after that adjustment. I have huge astigmatism and some monocular double vision (ironically in both eyes). I prefer ovf but have used EVF and ovf enough to deal with either.

The a7iii is a fine camera for low iso. I like the a7rii I have a lot. I’m curious if donating your existing k1 to 24mp would gain much for you.

[UncleVanya]

This article and downscaling may help as well:

How to Improve Low-Light Performance by Increasing Your ISO

[leonine]

This article and downscaling may help as well:

How to Improve Low-Light Performance by Increasing Your ISO

Thanks UncleVanya. I will check this out. And I will practice the use of progressive glasses on ground before going up in the air the next time.

[leonine]

Olympus OMD EM1X with Zuiko Pro 17mm f1.2 lens is an equivalent counterpart of the combination Sony A7 iii with Sigma 35mm f1.2. Smaller sensor but awe inspiring IBIS of 7 stops. Also, since wildlife photography is another genre I indulge in (as I said before), with the lightweight and excellent Zuiko Pro telephoto lenses being almost half the cost of their Sony counterparts, the Olympus seems like an interesting option. Of course, theoretically, it is not going to be any match to the Sony A7 iii for high ISO performance. However, if an APSC K3iii can take on the full frame Sony A7 iii in high ISO performance, the Olympus performance may be acceptable at high ISO. If it is ok till ISO 6400 and gives me two stops extra stabilisation, maybe the Olympus is worth considering? The priority remains the night time aerial photography, but the many advantages of the Olympus system for wildlife photography might be a good collateral advantage.

[Transit]

When ever people mention IBIS in here I wonder by what tech Pentax got a large white bird in there :-D
What happened to SR ?