PF Photography: Tips, Tricks, & Photo Sharing

[Andre]

I generally shoot astronomical and near-earth objects (satellites, etc) with a fully open aperture. It helps that the weather is cooler now, the camera noise is noticeably lower and the sky seems darker as well.

Maybe consider looking at the sweet spot idea.

That's the reason why I basically avoid full open aperture unless required for available light or bokeh. Most of the time, generally speaking, you hit the sweet spot, stopped down about two clicks and before diffusion sets in, giving a rather tight range for best aperture. 5.6 is a magic number.

 

[amal]

How do you find this one?

 

[Andy Resnick]

Maybe consider looking at the sweet spot idea.

That's the reason why I basically avoid full open aperture unless required for available light or bokeh. Most of the time, generally speaking, you hit the sweet spot, stopped down about two clicks and before diffusion sets in, giving a rather tight range for best aperture. 5.6 is a magic number.

It is true that aberrations (except distortion) decrease with decreasing aperture. But sometimes I need the biggest 'light bucket' I can get.

 

[navynuclear]

A path through the woods near my house.

 

[NileQueen]

Very picturesque.

 

[NileQueen]

Amal, I like yours too.

 

[AlephZero]

A question about image gathering from satellites in LEO, as used on Google Maps etc.

This is prompted by PF thread about a research paper where data about animals (cows and deer) was derived from images on Google Maps, and the paper claimed surprising (and not obviously believable) results.

Just for fun I looked at some Google Maps images of an area that I know well on the ground, which should have contained shown plenty of fields with cows and sheep - except there were virtually no animals visible on the images, and the few that were there (about 1% of the number I expected to see) were very blurred. Also there were also no vehicles on any of the roads, which is very improbable. (Cars that were obviously parked, near buildings etc, were clearly visible)

There was no problem about the image resolution at the highest zoom level (e.g. white painted road markings and even overhead power cables were clearly resolved), so I wonder if there is something about the image gathering technology which can't resolve moving objects, or filters them out. Long exposure times, because of the extreme telephoto lenses, for example? I couldn't find anything relevant the Web.

I'm specifically asking about satellite images here. Apparently in urbanized areas aerial photography is often used to give better resolution, and that does show road traffic, etc.

 

[Borek]

Just for fun I looked at some Google Maps images of an area that I know well on the ground, which should have contained shown plenty of fields with cows and sheep - except there were virtually no animals visible on the images, and the few that were there (about 1% of the number I expected to see) were very blurred. Also there were also no vehicles on any of the roads, which is very improbable. (Cars that were obviously parked, near buildings etc, were clearly visible)

I doubt there is plenty of time to take these pictures - after all, these satellites are rather low and fast. Usually I see plenty of cars - perhaps pictures were taken early, like 5 a.m., before the traffic started?

But then perhaps pictures are taken in some counterintuitive way (three line sensors using the same lenses?) and then postprocessed to get rid of artifacts of the moving objects? Just guessing here.

 

[AlephZero]

I doubt there is plenty of time to take these pictures - after all, these satellites are rather low and fast. Usually I see plenty of cars - perhaps pictures were taken early, like 5 a.m., before the traffic started?

Some images were clearly in sunlight with the sun high in the sky. From the farming activity visible they were probably taken in June. So I don't think the time of day explains the lack of road traffic.

 

[Andy Resnick]

I'm specifically asking about satellite images here. Apparently in urbanized areas aerial photography is often used to give better resolution, and that does show road traffic, etc.

Interesting... I never thought about this, but looking at NYC, around Times Square, using Google maps and Terraserver shows very few cars and people- much fewer than I would expect. The problem is not acquisition times- there are cars driving and people walking. The images may have been taken at odd times of day, but the shadows all seem to indicate 'normal' times.

Since the maps are generated based on many images, perhaps the images are chosen specifically to minimize the number of people/animals- images acquired in winter, for example?

 

[Andre]

Looked around a bit in my area, no traffic jams but certainly a lot of traffic at certain places.

Keep in mind that the orbits of these (this) satellite is rather rigid. So it can only make a picture of a certain area at a certain time and the next picture weeks? months? later. Then it's visible light, so there must be no clouds. For some area's that's very rare, but the least amount of clouds are in the early morning shortly after sun rise, before convection kicks into produce cumulus clouds.

So I can imagine that having a decent picture of certain areas is a tough job in the first place, and the amount of traffic would hardly be a selection factor. Maybe that summer pictures made at something like 5-6 am, minimizing clouds, are more often successful. Probably not a lot of activity then.

 

[AlephZero]

The lack of traffic is a bit of a side issue, but it struck me as being rather odd. The "invisible sheep" would have been in the fields at any time of day or night. Granted some of the cows might be out of sight being milked in early morning and evening, though.

 

[Borek]

Wow: a year long exposure using pinhole camera.

 

[fuzzyfelt]

Wow: a year long exposure using pinhole camera.

Wow!

 

[Andy Resnick]

Wow: a year long exposure using pinhole camera.

very cool!

 

[amal]

Amazing. The photo's too good.

 

[Andre]

Relatively cold here with a strong easterly wind do curious things to reed sticks at the lake before the water freezes over:

This is straight from the camera:

http://dl.dropbox.com/u/22026080/Natural%20ice%20sculpture_1.jpg

after some tone mapping and cropping:

http://dl.dropbox.com/u/22026080/Natural%20ice%20sculpture_.jpg

Edit: Same spot looking in another direction:

http://dl.dropbox.com/u/22026080/Natural%20ice%20sculpture2.jpg

 

[Andy Resnick]

Maybe it's not photography exactly, but my lab class is making holograms this month, using a kit (http://litiholo.com/). I had no idea how well the kit would work, but the students made some really nice holograms and enjoyed the process, so I thought I'd give it a try myself. I decided to try making a hologram of a computer chip:

http://img42.imageshack.us/img42/7021/dsc1626.png

Here's the hologram of the 'bare' chip:

http://img821.imageshack.us/img821/4233/dsc4757.png

It's *really* bright- I had to use a polarizer to cut the intensity down enough to take a photo. The next step was to make a hologram of the chip as viewed through a microscope objective:

http://img217.imageshack.us/img217/8514/dsc4741.png

And here's the result:

http://img85.imageshack.us/img85/4986/dsc47681.png

Not bad for a toy kit!

 

[Andy Resnick]

Here's my final hologram:

http://img192.imageshack.us/img192/1710/63mm2.jpg

The object is a computer chip, magnified with a 63mm Luminar. The holographic plate was placed near the back pupil plane, producing a virtual image at infinity. This image was taken with a 85/1.4, and since the virtual image is far away, the optics table etc. is out of focus.

There's quite a bit of optics involved with doing something like this- very non-trivial.

 

[Andy Resnick]

Today was the second half of an experiment- a professor from the Art department gave a special demo to my class. He turned a colleagues room into a camera (a camera obscura). It's really cool. Here's a couple images showing downtown Cleve-o, looking north to Lake Erie:

http://img252.imageshack.us/img252/8986/dsc93241filtered.jpg

http://img687.imageshack.us/img687/8324/dsc93251small.jpg

 

[fuzzyfelt]

Very nice!

 

[Andy Resnick]

Got some excellent shots of the ISS (space station) during tonight's flyover. Easy-breezy: I set the exposure by Venus (magnitude -4.7 vs. ISS @ -2.4, so I doubled the ISO to compensate) 800/5.6, 1/500s ISO 250, no mirror lockup. Trivial to track- I took about 120 shots over 5 minutes. My card reader is at work, so I'll post a montage ASAP.

 

[Andy Resnick]

Here's the whole series, no processing other than cropping and white/black levels. Seeing conditions were... "not optimal". ISS came into view from the NW and traveled approximately at a constant 40 degree elevation angle down to the SE.

http://img407.imageshack.us/img407/4131/montaget.jpg

The moral of the story is: 1) *fast* shutter speeds are essential. 2) mirror lockup isn't needed, and 3) a good tripod head is required. Even though I was only slewing at ~ 3 degrees/second, I could not have done this without a gimbaled mount- I was tracking with one hand and remote triggering the camera with the other.

 

[Andy Resnick]

Here's a cleaner version- I individually adjusted each frame and deleted the 21 worst:

http://img851.imageshack.us/img851/7452/montagegoodsmall.png

I can see how the ISS rotates as it passes; it starts out with the bright main truss on the backside, and then rotates into front view. It also appears that the station is executing a roll maneuver (with respect to me) during the pass, but that could be my imagination.

Here are some external timelapse videos from a camera mounted to the ISS with some hints as to what is moving when:

 

[Andre]

So just I got myself a http://www.sigmaphoto.com/shop/150-500mm-f5-63-apo-dg-os-hsm-sigma today. I did quite an elaborate research with on the shortlist also the Canon 100-400L (Turbo's lens) and the Canon 400mm F5.6L.

The Sigma won finally, due to the extended reach. As 400mm is hardly much of a gain compared to the 70-300. Maybe with tele extenders on the 400mm L, which has sufficient image quality for that, but it lacks the image stabilization.

I accepted the caveats of the Sigma, the weight and the soft image at full opening at maximum range. I tested that sort of randomly -not prepared- on these little bottles:

Oops, I did not spot that little dead bug at the time. I should have dusted first

But indeed it's soft full open as seen on this 100% crop on top:

But the bottom crop at F10 is pleasing enough to keep it. I think.

 

[Topher925]

That is one helluva lens. I was looking at buying a nice 400 or 500mm prime not to long ago for nature photography but couldn't bring myself to fork out that much dough so I bought a telescope and adapter instead (Orion ST80). Surprisingly good images for a hundred bucks but big, heavy, and difficult to use so now its only used for astrophotography.

I did recently get a sweet deal for a Pentax DA 70mm Limited. And while it doesn't have the reach of 500mm, 70mm is still not bad and its ridiculously sharp at f5.6 and beyond. Its so small and light it fits in my shirt pocket.

A shot with the 70mm at f2.4 ISO 200

100% Crop of above image

 

[Andy Resnick]

So just I got myself a http://www.sigmaphoto.com/shop/150-500mm-f5-63-apo-dg-os-hsm-sigma today. <snip>

<snip>
I did recently get a sweet deal for a Pentax DA 70mm Limited. And while it doesn't have the reach of 500mm, 70mm is still not bad and its ridiculously sharp at f5.6 and beyond. Its so small and light it fits in my shirt pocket.
<snip>

Yay! new toys! I put in for a new lens as well, we'll see how it does when I get it.

 

[Ms Music]

So just I got myself a http://www.sigmaphoto.com/shop/150-500mm-f5-63-apo-dg-os-hsm-sigma today.

I think I have that same lens, if not, one very similar. I may have to drag it out and play around with it and try to copy some of the stuff you do. I have barely touched it, but never was satisfied with its performance. And I didn't have the time to research it. I have always felt that A/ it doesn't work right, B/ my tripod isn't beefy enough for it, or C/ I too stoopid to use it correctly. I believe the correct answer is probably C.

Would you be willing to walk me through copying a few of your photos to see if I can truly eliminate option A and B?

 

[Andre]

Sure, happy to help out. I'll link to full size pix later today.

http://www.sigmaphoto.com/shop/telephoto-zoom-lenses and http://www.sigmaphoto.com/shop/telephoto-zoom-lenses?page=2 is the full line up of the long sigma's.

Obviously there are many reasons why the results may disappoint, then again you cannot expect the same quality from a budget 1K lens than the 10k lenses, especially the Canon 400mm II F2.8L is flat out sensational, but way to expensive for common sense. So I wasn't expecting a better result than the second crop in my previous post.

Anyway, compared to the result with the 100mm macro, there is still clearly quite some difference in quality.

the Sigma:

To elimate any possible factor that may degrade the picture, these were all made from a sturdy tripod obviously, Optical Stabilator off, and manual focus in life view, in which I can blow up the focus area. Then from life view (and hence locked up mirror) the picture is made using remote control, but a self timer would also work, elimating any vibration.

 

[Andy Resnick]

Interesting- is it just me, or is the color rendition different between the macro and tele? The 100mm seems to be more blue.

 

[Andre]

Interesting- is it just me, or is the color rendition different between the macro and tele? The 100mm seems to be more blue.

Sorry, Andy, I should have told that those pictures were not made at the same moment in time.

 

[Ms Music]

Sure, happy to help out.

Thank you very much!

So what would you like me to do? Photograph one thing with two lenses to compare (like you just did with the macro), or would you like me to try to copy your "Dead Bug On Glass" to compare to yours? I meant to look at the lens so that you would know exactly the differences between yours and mine (besides the fact that mine is probably at least 5 years old), but forgot before I had to leave this morning. Just let me know what is easiest for you to judge, and any set up parameters you would like me to use.

Thank you again! My trusted camera shop went out of business before I got the opportunity to talk to them about it, and I haven't found anything convenient to replace that shop.

 

[Andre]

Okay, so we should try and make photo's of the same subject with the same parameters (mainly distance).

So here is my idea, we take pix of AA batteries, seems to be a standard thing for photo testing. Brand isn't interesting, it's just that we know that they are the same size.

Next thing is to determine the magnification. 1:10 seems simple, that means that with 500mm distance to the subject is 5 meter and with 50mm it's 0.5 meter etc, but we have to add the focus distance to that. Actually that's not fully correct as Andy will be happy to point out, but it's a simple approximation, so for 500mm the distance to the sensor plane is 5.5 meters and for 50mm it would be 0,55 meters. So we can make several test shots with various apertures.

I will work on 500mm with F6.3 F8 and F11, and the 100mm at F8, it's sweet spot and I'll post the results in a bit.

 

[Andre]

I'm not altogether happy with the results so far, but this is something made with the 100mm at F8

If you just make something like that, I'll get similar pix with the 500mm tomorrow.

 

[Ms Music]

Remember, I haven't taken any photography lessons. I tried learning from the manual, but that was about the time that my memory decided to fail me. So if you get too technical...

Are the parameters something you can check with the EXIF data? (I think that is what it is called) Then you can correct my homework. I have had to resort back to plain old point and shoot.

Also, realize that free time is something I have little of. I will do my best to do what you want me to within a decent time frame. Just a warning!

 

[Andre]

Don't worry, just put a couple of batteries in the picture, roughly like that, using the TLAR^* method and show some 100% crops and I will try to match that as close as possible.

Oh and please reveal your type of camera.* TLAR = That Looks About Right

 

[Andre]

Meanwhile I went to the lake to test the long tube a bit for action and reality. All shots reduced to 20%. No cropping.

Those coots can really fight.

100% crop of the last:

 

[Ms Music]

* TLAR = That Looks About Right

LOL!

Ok, you're on. I will see how quickly I can get some batteries back to you. Just no fighting coots. I can't match that!

Oh hey... Just had a thought as I was about to click to post. How do I post the full size image? I think my photo sharing site that I use for posting on the internet shrinks them, and I have never tried PMing photos to know how that works. Should I email them to you?

 

[Andre]

Yes email is okay. Also a possibility is installing a dropbox, which makes it easy to share files. Here are some of mine in full size:

http://dl.dropbox.com/u/22026080/IMG_9916.jpg
http://dl.dropbox.com/u/22026080/IMG_2379hdn.JPG
http://dl.dropbox.com/u/22026080/verlanglijstje/IMG_0527_vlinder.jpg

 

[Ms Music]

Thank you for the info, I will look into that.

I found my exact lens, so now you know what the similarities and differences are between our two lenses.

http://www.sigmaphoto.com/shop/50-500mm-f4-63-ex-dg-hsm-sigma

And an Olympus E500 body.

 

[Andre]

Ah yes the "Bigma". A well known lens.

The older version you indicate is without optical stabilisation, which helps prevent motion blur. Moreover with the E500, a four thirds sensor, which is half the size of the original SLR film. This means that the lens and body combination has an effective focus of 1000mm. In the old days we had a simple algoritm that for preventing motion blur, you needed a shutter speed equal or better than the effective focus, so that would be 1/1000 sec. With the current lens quality, personally I find that even optimistic. This means that hand held, you should not go below 1/1000 sec. But obviously a tripod is almost inevitable. With those speeds you're likely ending up with maximum apertures, which is not a good idea with the long sigma's as mentioned before.

Also look how touching the camera, even on tripod, already leads to vibrations, you could image that this would also translate into motion blur, even on the tripod, so remote or timer control is highly advisable, to have these vibrations dampen out first.

So all in all pretty tough to control that Bigma beast.

 

[Ms Music]

Ahhhhhh, THAT explains it all. So is the best advice to sell it? ;) Or would it work with a newer and faster camera?

 

[Andre]

Always quite a responsibility to give advice, but I think I would sell it, but indeed an alternative would be to get a sensor stabilized (micro) four thirds camera that should be compatible with the lens. This is a real gem. At least that would solve the shutter speed problem, if it works of course. But would you have fun carrying so much weight around all day?

Another option would be to get a super zoom bridge camera.

 

[Ms Music]

http://dl.dropbox.com/u/22026080/IMG_9916.jpg

I like how the cresting wave BARELY catch the color of the setting sun.

Always quite a responsibility to give advice, but I think I would sell it, but indeed an alternative would be to get a sensor stabilized (micro) four thirds camera that should be compatible with the lens. This is a real gem. At least that would solve the shutter speed problem, if it works of course. But would you have fun carrying so much weight around all day?

Another option would be to get a super zoom bridge camera.

Honestly, I don't give up easy, so I will probably keep it until I buy a better camera. But I decided a while back I wouldn't do that until I actually could use it somewhat. And yes, it is a heavy beast to carry around, it is named Mongo for a reason.

 

[Andre]

Meanwhile, I'm looking for a title for this picture; 'drama on a rose leaf'? 'Ladykiller'?

http://dl.dropbox.com/u/22026080/IMG_7615-1.jpg

 

[Borek]

Lunch?

 

[dlgoff]

Take That

 

[Andy Resnick]

An embarrassment of riches in the night sky lately- a spectacular pass of the space station last night:

http://img402.imageshack.us/img402/7127/iss662012.jpg

If I push the exposure, the rest of the structure may be (vaguely) seen:

http://img151.imageshack.us/img151/8717/pushed662012.jpg

800/5.6, ISO 400, 1/1250s exposure. There was a comedy of errors this time- the sky was cloudy, and I was distracting myself by trying to get a good exposure reading off of Saturn- the ISS was 5 stops brighter, so by getting a 'good' exposure from Saturn, I could dial in the ISS setting easily. I wasn't checking the time and...

All of a sudden, this *blindingly bright* thing comes barreling out of he clouds, almost directly overhead. I had set my tripod to be able to look directly up (like this: http://www.richardpeters.co.uk/blog/wp-content/uploads/2009/06/vertical.jpg), which is hazardous since I have to step over a leg to pan the lens around.

So I swing the lens around and soon realize that I still have the camera set to 'mirror lockup'- this is *bad* since the ISS moves so fast. I push what I thought was the right button, but soon found myself in camera menu hell. I get that fixed and realize that my tripod is pointed in the wrong direction, so I have to pick the whole thing up and rotate it this way and that. Meanwhile the ISS is panning directly overhead, looking amazing- there was a moment where it seemed to actually slow down and stop moving.

The next chance is on the 9th, under similar conditions...

 

[Andy Resnick]

Another fantastic ISS flyover- this time I was much better prepared:

http://img594.imageshack.us/img594/4049/dsc46912.jpg

I'll post a timelapse when I get a chance to process all the images... time to go back out, M101 is sitting pretty...

 

[dlgoff]

An embarrassment of riches in the night sky lately- a spectacular pass of the space station last night:

http://img402.imageshack.us/img402/7127/iss662012.jpg

If I push the exposure, the rest of the structure may be (vaguely) seen:

http://img151.imageshack.us/img151/8717/pushed662012.jpg

800/5.6, ISO 400, 1/1250s exposure. There was a comedy of errors this time- the sky was cloudy, and I was distracting myself by trying to get a good exposure reading off of Saturn- the ISS was 5 stops brighter, so by getting a 'good' exposure from Saturn, I could dial in the ISS setting easily. I wasn't checking the time and...

All of a sudden, this *blindingly bright* thing comes barreling out of he clouds, almost directly overhead. I had set my tripod to be able to look directly up (like this: http://www.richardpeters.co.uk/blog/wp-content/uploads/2009/06/vertical.jpg), which is hazardous since I have to step over a leg to pan the lens around.

So I swing the lens around and soon realize that I still have the camera set to 'mirror lockup'- this is *bad* since the ISS moves so fast. I push what I thought was the right button, but soon found myself in camera menu hell. I get that fixed and realize that my tripod is pointed in the wrong direction, so I have to pick the whole thing up and rotate it this way and that. Meanwhile the ISS is panning directly overhead, looking amazing- there was a moment where it seemed to actually slow down and stop moving.

The next chance is on the 9th, under similar conditions...

Another fantastic ISS flyover- this time I was much better prepared:

http://img594.imageshack.us/img594/4049/dsc46912.jpg

I'll post a timelapse when I get a chance to process all the images... time to go back out, M101 is sitting pretty...

Thank you for sharing these images (/w explanations). And the M51-Whirlpool Galaxy images too.