[Ed Hurst]

Presumably a large number of high ISO shots, aligned and stacked (for noise reduction), wouldn't look so good.

[TDvN57]

Presumably a large number of high ISO shots, aligned and stacked (for noise reduction), wouldn't look so good.

You mean something like +/-140 shots at 3 sec stacked and then processed like crazy? Hmmmm, yes I agree a single 400 second exposure is better, sounds not too difficult to keep aligned by hand using the slot on top of the lens handle.

[kaseki]

You mean something like +/-140 shots at 3 sec stacked and then processed like crazy? Hmmmm, yes I agree a single 400 second exposure is better, sounds not too difficult to keep aligned by hand using the slot on top of the lens handle.

Aligned to the projected angle subsumed by a single pixel? Let me check my birth certificate to affirm that I wasn't born yesterday.

[TDvN57]

Jokes aside lest I test the boundaries of decency and risk insulting the intelligence of others.

The Orion picture is a stacking of abt 135 pictures taken with the 645z and 600 lens with 1.4TC mounted on an iOptron Skyguider Pro with a 50mm guide scope. Exposure is 3 seconds and the rest is all on the EXIF data. The Skyguider is too small for the payload and can only manage a maximum exposure of 3 seconds. Even at 3 seconds the stars already show elongation. The stacking was not really necessary since the detail in each frame is almost the same as in the stacked version. Perhaps the stacked version has a bit less noise. Sequator adds together the accumulative exposure of all the frames and writes the accumulated result in the EXIF data as the exposure value.

I fully trusted that suggesting to hand guide a 600mm lens with a 1.4TC for a continuous exposure of 400 seconds to be so absurd that the intended satire would be obvious. How mistaken one can be...

[kaseki]

Sorry if my reaction seemed sincere. I did appreciate the absurdity, including the previous stopping the world. I just couldn't resist commenting on it with all the apparent seriousness that it was presented with. Unfortunately, text communication is even worse than masked communication; first all the facial language is removed, and then voice tonality is removed.

And thanks for clarifying the 405 seconds value was software provided; I had thought that you had hacked the EXIF directly. The modified EXIF in this form is potentially misleading; single shot exposure and number of frames would be more useful for clarity.

[TDvN57]

All good thanks Kaseki. The ancients believed that the written word should be kept from general population, because they argued that it is such a strong form of communication that we wont be able to handle it and will eventually drive us all into insanity. Perhaps some truth in that if we look at current world affairs and how people react to misleading text messages delivered by a virtual bird....

Anyway, back to photography:
I believe in the astro world they track the actual accumulative exposure, which is why you sometimes see absurd exposures of several days or hours long. Thus the reason astro stacking programs will accumulate the exposures of the used frames and write it into the new file's exif data. I am only dabbling with it and dont have the funds to buy a Takahashi refractor scope with a three inch flattened image plane that will light up my 645z (or perhaps even better the 645z IR - infra-red version), nor do I have the funds for a tracking goto head like the Meade LX850 that can really do long exposures with a single shot. You can literally buy a house for that kind of price, which is fine for the folks with the interest and the money. So now I play with an iOptron tracker that is designed for really lightweight equipment and I take my shots in between the clouds and at an angle where I can balance the rig without burning out the servos on the iOptron. It adds to the fun no doubt.

[kaseki]

@TDvN57: Thanks for improving my knowledge base, and thence, if Fortuna smiles on me, my insight.

[texandrews]

This month I had to do an odd shoot at my museum (my main client). We needed a series of individual shots and a stitched pano of a 75 foot long by 10 foot tall painting that is supposed to be installed sculpturally in a draped fashion. The artist in question did these sorts of paintings in the mid 1960's to mid 1970's. Almost no images exist of these paintings rolled out. While prepping the painting for a test install, we did some prep shooting and individual captures for the Conservation dept. I did some shots off a rolling ladder from the bottom edge and successfully stitched them together in a pano, but the perspective corrections and other capture issues led to the corrected top edge being softer than I'd like---fine for a general reference and even reproducable in a smaller size, but not as nice as we would have liked. So, we decided after de-installing to give it another try, this time with the 645Z and rigged so we could attempt a shot from directly above. So, here we go:

The first couple of shots show the rig I worked up. You'll see a Bogen/Manfrotto Magic Arm, a Super Clamp, a Promaster Multifuntional Clamp, a Promaster platform on top of a Chicken Foot monopod for the laptop, a purpose built plywood brace, a GlideGear boom, some speed clamps, aircraft wire tethers for the camera, TetherTools cable, and a bunch of white gaff tape which was used as insurance in case something got loose---along with the aircraft cable this was to ensure NOTHING could fall on top of the painting. This was all secured into a JLG man lift with its cage extended----that gave me about 24-ish incehes past the lift wheels, and the boom plus camera another 30-ish inches beyond that, so we could be assured of nearly 4 feet over the canvas below. Not quite the center as I would have preferred, but much better than shooting from the bottom edge.

[barondla]

This month I had to do an odd shoot at my museum (my main client). We needed a series of individual shots and a stitched pano of a 75 foot long by 10 foot tall painting that is supposed to be installed sculpturally in a draped fashion. The artist in question did these sorts of paintings in the mid 1960's to mid 1970's. Almost no images exist of these paintings rolled out. While prepping the painting for a test install, we did some prep shooting and individual captures for the Conservation dept. I did some shots off a rolling ladder from the bottom edge and successfully stitched them together in a pano, but the perspective corrections and other capture issues led to the corrected top edge being softer than I'd like---fine for a general reference and even reproducable in a smaller size, but not as nice as we would have liked. So, we decided after de-installing to give it another try, this time with the 645Z and rigged so we could attempt a shot from directly above. So, here we go:

The first couple of shots show the rig I worked up. You'll see a Bogen/Manfrotto Magic Arm, a Super Clamp, a Promaster Multifuntional Clamp, a Promaster platform on top of a Chicken Foot monopod for the laptop, a purpose built plywood brace, a GlideGear boom, some speed clamps, aircraft wire tethers for the camera, TetherTools cable, and a bunch of white gaff tape which was used as insurance in case something got loose---along with the aircraft cable this was to ensure NOTHING could fall on top of the painting. This was all secured into a JLG man lift with its cage extended----that gave me about 24-ish incehes past the lift wheels, and the boom plus camera another 30-ish inches beyond that, so we could be assured of nearly 4 feet over the canvas below. Not quite the center as I would have preferred, but much better than shooting from the bottom edge.

Wow! Very cool setup. Great technique to record a very difficult piece of art.

Thanks for sharing,
barondla

[texandrews]

In this series you can see me in the lift. My hand is raised to use the wireless remote to trigger the shutter. The wired remote would have been preferable had it been long enough, but it would have required me to be out further in the cage which was already shaky with movement---those things sway at fuller extensions like this (it goes higher). I would have liked to be higher a bit as well, but you can see I was already up in the lights. Speaking of which, I had to place or replace bulbs in about 40 lights---all of the cylindrical cans. The wall washers were all turned around. I lit about 30 feet of length and had to move and reposition the lift, and those are other members of the Exhibits and Conservation teams acting as my spotters so I would not run over the painting (can't see the wheels from the cage) and also came into about the same spot, roughly 3-4 inches from the edge. I controlled the lift from above with its joystick but they aren't well suited to very fine movements.

We had to move the lift initially because rolling this painting is very tricky and also it's fairly heavy if you're trying to move its whole length. Because of Covid restrictions we couldn't have as many people as we would have liked, so the compromise was to shoot about half of it moving the lift, and then to begin the roll to bring the unphotographed sections under the stationary camera. I wish we could have done the whole thing like that---there were focus issues.


I was shooting with the Lightroom plug-in, and it's handy but the shutter button doesn't allow for the autofocus to activate very well. That's why I also used the remote, and used the focus button with it. Better tethering is now one of my big deal upgrade wishes for any new 645 from Pentax---it's ridiculous that Image Transmitter 2 is no longer available(except on Ebay)! I wish I had known beforehand that I would run into problems. Previously I had shot tethered in the studio off a tripod and mostly done critical focus with live view, but here that was impossible. In retrospect I wish I had ginned up a high contrast target we could have deployed somehow to get focus. Mostly I shot at f5.6----even with all those lights it was still dimmer than I would have liked and my shutter speed was much slower than I really wanted. Waiting for the lift to settle down was a challenge---even breathing shook the cage slightly. I eventually used f8 just to get a little more DOF leeway, underexposed.

So, that's my contribution to "behind the scenes". And btw, these are strictly behind the scenes! Even sharing them here is a little close to the edge of acceptability, which is why I am not identifying the artwork, artist, other people in the shot, or the museum. But, hope you enjoy and get to have a chuckle. The first 3 were my phone, a Samsung Note 9, and the last 3 were one of the crew's phones, I think an Apple (the Samsung is clearly better!)

[672]

Great behind the scenes texanandrew. I wouldn't want to be driving that lift!!! (into the painting). On another note , I am prepping for a straight down shoot and am using AF fine tune adjustment to set true focus pointing straight down. With AF lenses, the elements float and the fine tune adjustment is different for normal straight ahead shooting, versus straight up, or straight down. For my current goals of being at 28mm on the wide zoom looking straight down I've got AF fine tune adjustment all the way to -10 and wish it went to -12 or -15....

Just something to look into for your 35mm as it will help to nail point of focus instead of relying on greater DOF.

[RICHARD L.]

Sometimes, all it takes is setting up the tripod and turning around.

[texandrews]

Great behind the scenes texanandrew. I wouldn't want to be driving that lift!!! (into the painting). On another note , I am prepping for a straight down shoot and am using AF fine tune adjustment to set true focus pointing straight down. With AF lenses, the elements float and the fine tune adjustment is different for normal straight ahead shooting, versus straight up, or straight down. For my current goals of being at 28mm on the wide zoom looking straight down I've got AF fine tune adjustment all the way to -10 and wish it went to -12 or -15....

Just something to look into for your 35mm as it will help to nail point of focus instead of relying on greater DOF.

Thank you for that tip! This would have been much easier focus-wise had I been able to stay in one place, of course. Because I was up in the lights and coffered ceiling, I had to go up and down a bit, and that was an issue. Really started having the problem after the conservators asked for some detail shots of problem areas they want to track over time, and those shots were done with the lift all the way down. Swapping lenses wasn't on that day, sadly. Not being able to focus from the tether was super annoying. Guess I'm going to have to cough up for the Image Transmitter 2 software (on a CD/DVD disk! omg...I don't even have drives in my computers anymore....)

[mikeSF]

Fun topic, and Ed, that first set is as good as it gets!

I may have a couple to share, sort of.

Pirates in Marin

and courtesy Jamie Baker:

[RICHARD L.]

What lens should I use ?


K3, K1 or 645Z on the Bellows ?


@&?%$$#@ Where is my pot of white paint to adjust focus ? %&$##@


Ah ! Finally. Nice results ...