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Messages - jrista

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1486
Landscape / Re: Deep Sky Astrophotography
« on: March 21, 2014, 03:10:52 AM »
Jrista...simply outstanding! 

After reading through your posts I have to say that I'm impressed by your knowledge, and thankful for the time you've taken to "write a short book" on the subject in this thread!  ;D

Jon, that is magnificent! Have you considered posting some tutorials on astro photography? I would love to learn how you make those images, they are just stellar.

Thanks, guys! For all your kind words. :)

I'm happy to write some tutorials. I have an area set up on my blog at jonrista.com for that. I'd love to see more people get into astrophotography. I've been limited myself to just the moon and larger solar system objects, and maybe some of the larger nebula like Orion, until I got myself a good tracking mount. It's a complex form of photography, but if you like a challenge and like all the gadgetry and math and tinkering and experimenting that goes into astrophotography, you'll love it!

I'd like to get a little bit more experience under my belt before I do write any tutorials...some things I'm still learning and refining my knowledge of. Learning more about the software options, for one. There are a LOT of processing techniques I still need to learn, and some additional tools (like PixInsight). One of the biggest issues, one of the most difficult to deal with unless you get a $20,000 mount, is tracking performance. I'm somewhat "lucky" to be imaging at "only" 600mm...most telescopes are around 1600mm and longer, some of the larger ones are well over 3000mm, and with a barlow, you can get as long as 9000mm or longer!

There is inherent error in all tracking, due to imperfections or precision limits in gears and worms and the like. It's called Periodic Error. There are also sources of non-periodic error, such as seeing (atmospheric turbulence), flexure (the mechanical flexing of anything on the mount, including the tripod, the mount itself, the telescope and guidescope, etc.), wind, etc. A real high end mount, like the 10Micron GM2000HPS, which uses "absolute" encoders which track the absolute position of both the RA and Dec axes with extremely high precision, is basically immune to most of these sources of error. Periodic error, unexpected movement due to wind, even seeing effects, are delt with by the absolute encoding and built-in sky modeling in a mount like the 2000HPS. That sucker generally costs about $24,000 for a complete package, though.

Tracking issues on lower end mounts are usually delt with by "guiding". Guiding uses a secondary scope, usually smaller than the primary scope, along with a small video camera and special guiding software, to lock onto a specific star, model it's shape, identify the "centroid" (an identifiable center point that can be reliably found and regularly tracked), and send correcting guide signals to the mount to tell it to slow down or speed up relative to "sidereal rate". This can solve tracking errors that are primarily due to periodic error. If you use "Off-axis Guiding", you can also solve tracking error that might be caused by various sources of flexure (which pretty much every scope is going to have to one degree or another), slight movement due to wind, etc.

Tracking is probably one of the toughest things to learn about astrophotography, but also one of the things you have to tackle early on to get images like the Rosette image I last shared. You have to get tracking error, in terms of arcseconds, to an average level below your image scale (the relative size of a pixel in arc seconds)...for example, the 7D has 4.3µm pixels, and with a 600mm lens, my image scale is 1.48" (arcseconds)...so for ideal tracking, my RMS error needs to be ~0.7", about half the image scale. I have been able to get my tracking accuracy down to 1" to 1.2", but I haven't yet figured out how to consistently get it below that.

Once I do, I'll be more able to image things on a consistent basis, and I'll have more data to stack and learn processing techniques with. I hope to be there by summer, at which time I'll probably start writing tutorials on my site. 

1487
Landscape / Re: Deep Sky Astrophotography
« on: March 21, 2014, 02:51:41 AM »
Fantastic work JRISTA and many thanks for all the information you've provided! I didn't expect such results were possible. This is great stuff.

Thanks! And your welcome. :) It's possible to do MUCH better than I have. I'm still a relative novice. Even with just a basic telescope and a DSLR, there are people out there who are more skilled and have gotten far more beautiful images than I have. I was actually surprised that the Canon 7D did as well as it did on Rosette...lot of hydrogen alpha (Ha) emission there, however most DSLRs, including the 7D, only pass about 15-20% of Ha wavelengths (it's only a 3nm bandpass). The fact that I was able to extract as much red nebula detail as this is pretty lucky.

1488
Landscape / Re: Deep Sky Astrophotography
« on: March 21, 2014, 02:49:23 AM »
Amazing pic, jrista. How do you even know where to look? I had always thought you would need a telescope (and a big one) to take such images. Amazing.

Thanks!

As far as finding things, I use Microsoft WorldWide Telescope (WWT) to point my mount. Before I do that, I "model" my skies with a plate solving tool, which can figure out the stars and deep sky objects in a photo by referencing indexes and doing spatial mapping and modeling. The plate solvers "sync" their model to the mount, after which I am able to point very accurately, usually within an arcminute or two, sometimes within arcseconds. So, all I really have to do is use WWT to find what I want to image, highlight it, and tell it to "slew" the mount. That's all there really is to it! :)

1489
Landscape / Re: Deep Sky Astrophotography
« on: March 21, 2014, 02:46:32 AM »
Thanks Jrista!,

I'll get much more serious once the timer release arrives, hopefully in about a week.  The moon has been too bright too.  I have the stacking software downloaded but haven't tried it and don't know the process at the moment.  Yes, once the gimbal is perfectly balanced it doesn't impact the tracker very much since it is so smooth - that'll be a positive.  Of course I'll go beyond 30 sec as soon as I can do it with the timer.

The big problem for me is going to be knowing where to aim.  Any good references on that??

For anyone that has purchased the iOptron skytracker, that wobbly base is an obvious design flaw.  The external ring and 3 lock screws I added is just night and day better.  I posted the picture on the other star thread.

Jack

Oh yes, the actual stand upon with the mount sits is probably one of the most critical factors, and is usually the limiting factor in terms of maximum capacity of the mount. A lot of midrange mounts ($1000-$3000) have capacities that top out at around 40-50lb, however that is usually because that's all the tripod or pier can handle before it begins to buckle. The mounts are often capable of handling a little more capacity than that if you place them on a sturdier tripod or pier.

As for knowing where to look, that's where an equatorial tracking GOTO mount is particularly handy. The GOTO mounts can be told to "go to" a set of RA/Dec coordinates, and they will. You have to have very good alignment for that to work...you need to have pretty precise polar alignment, and you need to align the goto feature itself by modeling the proper coordinates for known stars. Once you are polar aligned and have properly modeled, then you can use planetarium software (I use Microsoft WorldWide Telescope) to control the mount via ASCOM, and you can point at pretty much anything in the sky.

These days, I am now using plate solving. With either AstroTortilla+BackyardEOS, or Sequence Generator Pro, I plate solve, which takes a picture with my setup, and runs it through Astrometry.NET, which models the stars and DSOs in the image, figures out where you are actually pointing, then "syncs" the mount with a corrected model. It sometimes takes a few iterations of plate solving to fully correct the modeling of the mount, but once it does, pointing accuracy can often be within 50 pixels! (By default, pointing accuracy may be off by as many as a few tens of arcminutes on most mounts...accurate modeling is really what gives you good pointing accuracy, and that is usually only available on high end, $10,000+ mounts. I purchased Orion Atlas because it has EQMOD compatibility, which makes plate solving a very reliable option with SGP or AstroTortilla.)

I don't know if the SkyTracker has any computer control capabilities. If not, I'd check to see if it has any kind of control capabilities with a hand controller, as that may allow you to do some basic modelling for basic GOTO functionality. If you don't have those (and I suspect not, most of the ultra wide field mounts don't offer that, as most people are going to be using 14mm to 50mm lenses, in which case all you need to do is point it in generally the right direction), then your just going to have to learn the sky, and learn how to do iterative refinement. It doesn't take long, once you start spending time outside under the sky, to learn the positions of the key constellations and what the stars in them look like in a photo. Once you get that far, you eventually learn how to recognize when certain important stars for constellations are in the frame. From there, you can "star hop"...change where the mount is pointing little by little and "hop" from known star to known star until your in proximity to what you want to image, then you can basically do a spiral search, taking an image, moving, taking and image, moving until your framed the way you want to be.

I think your case is a little more unusual, as your using a 300mm lens on a SkyTracker. Generally those mounts are used for much wider field work...I'd say at most 100mm, and generally probably closer to 24mm to 50mm. At 300mm your probably at the limits of what that little mount is capable of. If you ever want to stick the 1.4x or 2x TCs on your lens, then I would highly recommend you bump up to the next level...like the Orion Sirius. That's a full blown Equatorial GOTO mount, and you could then (with an EQDIR cable, bought separately) have complete computer control over the mount...and you could plate solve, use planetarium software for pointing, and do full blown imaging like I am doing with BackyardEOS, Sequence  Generator Pro, Nebulosity, etc.

1490
Technical Support / Re: More reach
« on: March 21, 2014, 02:32:42 AM »
I use a 70-200 f2.8 IS II. Not the f4 model  :)

Ah! Sorry! At least you do have the f/2.8 II, though...that's a great lens!

So if I drop one stop of aperture, I bump up one notch of ISO? I'm looking through my library and trying to gauge the ISO's, apertures and focal lengths used and what I could wish for.

You either notch ISO up a stop, or, if you have shutter speed to spare, you reduce shutter speed by a stop. I don't shoot motorsports...I do shoot my friends model airplanes in flight every so often. Owning the 7D myself, with it's smaller pixels, it's tougher to get away with reducing shutter speed unless you specifically want some motion blur. So generally speaking, every stop of aperture lost usually means a stop increase in average ISO used.

Of the events I've been to, most of the time 200 is more than enough, but as a spectator there is only so close you can get to the track, and catch fencing does rather limit your view a lot of the time.

Airshows, again 200 is more than enough a lot of the time, however there are times when a bit more reach for the smaller planes (biplanes, spitfires etc), or when they are manoeuvring further away would be useful.

Wildlife is third on my list after motorsport and airshows.

Since wildlife is the tertiary activity, then I have another option for you. I don't know what your budget is, although it sounds like $2500 may be around the limit? I have been subscribed to CanonPriceWatch.com for a few years now. I have a number of alerts set up in their system. Over the last couple of months, I've been getting a LOT of alerts about Canon's Mark II telephoto lenses. Several times over the last week and a half, I've been alerted of USED Canon EF 300mm f/2.8 L II lenses clocking in at ~$2700-2800. Given the list price for that lens, that is a superbly good deal!

For your motorsports and airshows, I really don't think you could do better than a 300mm f/2.8 II. It's eminently hand-holdable, the big aperture is ideal for the kind of fast moving subjects you shoot, and it easily adapts to 420mm f/4 with the 1.4x TC, which is still well within the realm of usability. If you really need it, you can always slap on the 2x TC for 600mm f/5.6 performance. I rented this lens a couple times a year and two years ago. I used it with both teleconverters. IQ with both was EXCELLENT. Even with the 2x TC, it performed as well or better than my 100-400mm lens, and the boke was always superior, regardless.

For $2700, even though that might be a bit beyond your desired budget, I really don't think there is a better lens for the kind of subjects you photograph. These deals come an go, and I've seen the lens sell used for as low as $2399. I'd go to CanonPriceWatch, find that lens, and set up some alerts for the used price range you would find acceptable (I'd say $2300-$2900 is very good for used), and take advantage of the next deal. New, this lens costs about $7300, and new deals rarely go below about $5500. I myself will probably be picking up a used copy, so long as it was well cared for, next time a $2700 deal rolls around. It's just too cheap to pass up.

1491
Technical Support / Re: More reach
« on: March 19, 2014, 06:29:28 PM »
At the moment, I don't think you could really do better than the Tamron 150-600 as far as focal length goes. For the price, it's quality can't be beat. It's barely more than twice the cost of a 2x teleconverter, and it will get you considerably more focal length, which means much greater magnification (relative subject area in the frame at 600mm is 2.25x greater than with the 70-200+2x TC...even if the 600 is a tough soft in comparison (which I doubt), your packing so many more pixels on subject that it's still way worth it to get the Tamron.)

Regarding hand-holding technique, that improves with time. It does take some skill to learn how to hold a long lens and get stable shots, with or without image stabilization. You should get used to it at either 400mm or 600mm, regardless of which option you choose.

As for ISO, you will indeed need to be using higher ISO settings at those apertures. Your losing a stop or more of light, so if you used to hover around ISO 1600 at 200mm, then it's no surprise that your around ISO 3200 at 400/600mm.

Finally, given the subjects you shoot, with the exception of wildlife (which is often largely stationary), you might actually find that fast aperture is actually more important than focal length. Motorsports and airshows both involve fast moving subjects. For both cases, I would offer that a 7D with 70-200 f/4 is probably the worst combination. You really want bigger pixels and the fastest lens you can get your hands on...like the 70-200 f/2.8 (I don't know which 70-200 you have). I'd offer that physically getting closer for motorsports is better than sacrificing aperture for longer focal length. As for airshows, I know a couple guys who do that almost exclusively. Both own the EF 300mm f/2.8, and one owns the EF 200mm f/2. Those are their staple lenses. They rarely go to longer focal lengths (and the one often favors the 200mm) because they need the wider field to include the whole plane and enough white space around it to make a pleasing composition.

So, assuming you currently have the 70-200mm f/4 lens, I would actually offer that getting the 70-200mm f/2.8 II lens is probably another alternative, and one that might support your motorsports and airshows better than a longer focal length. Those subjects just move so much faster on a consistent basis than wildlife does. If you really needed to, you could slap the 2x TC onto that, and you would have a 400mm f/5.6 lens, albeit one that doesn't quite offer the same IQ as the 400/5.6 prime or 100-400. If you primarily do wildlife, and motorsports/airshows are a distant second, then I'd get the Tamron 150-600, and just work out your hand-holding skill (as it will get better over time.)

1492
Landscape / Re: Deep Sky Astrophotography
« on: March 19, 2014, 06:06:16 PM »
Here is Rosette nebula, in the constellation Monoceros (Unicorn), just to the east of Orion. Integration of 30x210s ISO 800 light frames, 30x darks, 30x flats, and 100x bias. Total exposure time 1h 45m.



I wanted at least twice the light frames, and it seems I could probably do much better with 60x480s ISO 400, rather than ISO 800. Next time I get the chance, which may be tonight, I'm going to give it another go, and see if I can get more dim nebulosity in the periphery.

1493
Landscape / Re: Deep Sky Astrophotography
« on: March 19, 2014, 06:01:11 PM »
Truly MAGNIFICENT!

Thanks! :)

Not sure I should even open my mouth here as I'm new to this and indeed very uneducated in the subject.  I have modified my iOptron skytracker to add rigidity to the base and allow my gimbal head to be mounted on a horizonatal plane.  I removed the gimbal swing arm and mounted my 300 X1.4 and was able to get quite good shots with pretty accurate focus.  Aligning Polaris was not too much of an issue but it did need tweaking.  With the now horizontal orientation of the iOptron base the gimbal worked really well in allowing smooth balanced movement of the lens.

However, last week I tried 300 X2 and found getting focus to be tricky becasue of lens movement due to lack of rigidity.  I will try again and then perhaps have to accept that it's impractical.  I'm not fully convinced, but obviously what I'm trying to do is not what anyone who is serious about the stars would be willing to accept.

An even bigger problem is my ignorance of where to aim.  Also I have not yet tried stacking.  I did post a shot in the other thread but I guess it's no longer active, so here's a sample at 420, 30 sec.  My remote timer release is in the mail, so that'll help.  Otherwise I'm all ears.

Jack

It looks like you want MUCH longer exposures. I'd say four times as long, 120 seconds, if you can manage it. I would start at 300mm, and not use the 1.4x TC. The longer the focal length, the more demanding the whole system is going to be on stability. You can do quite a bit of amazing work at 300mm...that would be wide field, so you could, for example, image the entire heart nebula in Cassiopeia, or get a wide field image of Rosette. That big lens is going to be your biggest drawback with the SkyTracker...you will need to get it as balanced as you possibly can, and make sure your polar alignment is as dead on as you can get it. Also, make sure you are imaging wide open, or close to it. You want f/2.8, although that might result in funky star halos, f/3.2 and f/3.5 are probably going to be your best friends.

1494
Landscape / Re: Deep Sky Astrophotography
« on: March 19, 2014, 05:57:33 PM »
Well, first, they aren't separate images. They are just crops of the same image.

The scaling isn't the same kind of problem in astro as it is in regular photography. The general rule of thumb in astrophotography is that you SHOULD be OVERsampling. You don't want your stars to be pixel size...you want them to be several times pixel size. The rest of the softness is due to a number of things...tracking error, polar misalignment (in my case, at the time, it was about 2' misaligned, or 1/30th of a degree, so not all that bad, really), seeing. Seeing refers to atmospheric turbulence that causes stars to wobble and jump around.

So, the image is exposed and scaled properly...exactly as it should be, really. With a longer focal length, I'll only be oversampling that much more, but that's a good thing. The more pixels I can pack into any given object, the better.

I was at f/4 ISO 400 for this series, although my exposure times differed. I took three separate sets of exposures, because the dynamic range in Orion Nebula is massive. The 30 and 60 second exposure sets were used to dim the core, which was indeed overexposed in the 120 second exposures. Additionally, mixing and matching ISO settings makes removing noise very difficult. Read noise levels increase as ISO drops, fixed patterns change, etc. meaning you need to use different sets of dark frames. However the semi-random and random noise contributions are also different, and when stacking images from different ISO settings, you usually end up with the worst common denominator in noise...thus noise is usually higher.

The best approach is to use a single ISO setting, at the same aperture, and only vary shutter speed. That minimizes the variables, and allows the intelligent aspects of stacking software (such as dynamic dark scaling) to work it's magic and give you the best results.

1495
The 300-600 MkII supertele lenses were something like 18 months from development announcement to launch.  Hopefully Canon can do better...

Canon did have earthquakes, tsunamis and melting nuclear power plants to contend with during the creation of the Mark II series as well. Gotta take that into account. ;)

1496
EOS Bodies / Re: Calumet Photo Files Chapter 7 Bankruptcy
« on: March 14, 2014, 10:09:28 PM »
I think Calumet has had enough financial problems that they are having a tough time getting supply from manufacturers. That would explain why you generally have to special order everything from them...they can't get any supply until it's a guaranteed sale.

I think management, somewhere along the line, massively screwed something up, and it's ultimately going to cost the company everything. Kind of sad. So many brick and mortar camera stores have gone up in smoke recently. We used to have both Mikes Camera and Wolf Camera here in Colorado. Wolf Camera decided to pick a fight with Canon...obviously, they lost, and they are completely gone now, bankrupt.

Mikes Camera moved into most of the old Wolf Camera stores, but they really don't look all that much healthier these days...they too are trying to push photo classes and training at $100+ a pop, print services, any kind of repeatable service they can think of, because they don't seem to be able to move physical product. (And it's no surprise, they mark up the prices on most things astronomically high, which isn't competitive with online, and because they get so few sales, they feel they can't reduce prices, etc. etc. down the rat hole...)

Maybe we'll see camera manufacturers start to act like smartphone manufacturers. Instead of these general purpose stores that sell all brands, we'll see the Canon Store, and the Nikon Store, and the Sony Store.

1497
Landscape / Re: Please share your snow/ Ice Photos with us in CR.
« on: March 14, 2014, 06:14:47 PM »
Anyway...had to respond. You shouldn't even have to wonder about whether CO2 could be a pollutant or not. It isn't, can't, never will be. It's a trailing indicator of global climate shifts, not a leading indicator. All of the modern "science" that points to CO2 as a cause of anything is easily falsified, because it's science that is chasing a lagging indicator that itself is chasing the actual cause. (Not to mention the fact that the whole "global warming" issue has given a lot of politicians a lot of power and control over the unaware populace who hasn't ever taken the time to investigate the issue for themselves, or look for evidence contrary to the political agenda.) If there is any indication lately, the fact that we are entering a multi-decades long solar lull and the impact it's had on this recent winter should be of greater concern. The recent "solar maximum" was a rather pitiful one in the grand scheme of solar peaks, and winter couldn't wait to crush the 2013 summer with some of the largest flooding (globally) on record, and some of the coldest cold snaps in decades. If your sick and tired of this winter...just wait until it's 55° during the heart of summer and -45° during the heart of winter, and your energy bill skyrockets to become your primary expenditure next to your mortgage... (Of course, if/when that happens, I'm sure someone will figure out a way to blame humanity for causing it all... :P)

It's a "greenhouse gas", if you want to get technical.  Thanks for weighing in though, you and I are in agreement on issues like these.  (An even stronger greenhouse gas is methane...not that you didn't know.)

It is a greenhouse gas. The fallacy is in the notion that the greenhouse effect caused by such gases is infinite. It is not. The greenhouse effect has it's limits, the warming caused by such gases has an asymptotic relationship in terms of gas volume to effect ratio. BTW, the single most powerful "greenhouse gas", by a MASSIVE margin, is water vapor. The only reason CO2 has been demonized is is radical environmentalists couldn't find a way to demonize water vapor. ;P I'd also note that methane is also a significantly more powerful greenhouse gas than CO2. As far as CO2 goes, given it's minuscule ratio in our atmosphere, has an impact on global temperatures that is effectively "noise" relative to H2O and CH4.

1498
EOS Bodies / Re: EOS 7D Replacement Mentioned Again [CR1]
« on: March 14, 2014, 01:43:51 AM »
"new" software features I'd love to see:

Built in Intervalometer

Ability to do more than 7 shots bracketed at a time, "pick your own" kind of thing.   I do large HDR exposures in 1/3 stops, typically 20+ frames.  It's a pain to do it quickly.. Would be nice if there was no set limit on the number of bracketed shots.

Technically speaking, given how the math works when blending HDR, you shouldn't need 20+ frames. Not unless your trying to photograph the sun at the same time your imaging that star that's about to be occluded by it. :P With more than 20 frames, spaced a couple stops apart, you could get like 30+ stops of dynamic range. I don't know what your photographing, but I think you've gone a little overkill.

1499
Landscape / Re: Please share your snow/ Ice Photos with us in CR.
« on: March 14, 2014, 12:59:09 AM »
:) :) :) Jrista, that was tongue in cheek designed to poke fun and now you've gone and made it a serious topic! ;)

Don't worry, as an electrical engineer I was forced to assimilate a certain amount of chemistry, although that was long ago :(

Americans have Al Gore, Canadians have David Susuki!  All these guys live the life while trying to put guilt trips on everyone else.

Here in Alberta we're supposed to feel guilty about having lots of "dirty" oil. LOL

Jack

LOL

And, if it wasn't for Obama's blocking the pipelines, you guys could be shipping all that "dirty" oil down here to us US consumers, making a boatload of money off of it. :P

1500
Just a quick question on behalf of a work colleague. I should say I'm very sceptical, but anyway.....

He uses a 5D3 and 70-200mm f2.8 mk2 to shoot football matches. Normally he would keep things at f2.8 (thanks to the near-constant Scottish gloom) and let the camera do the rest. Whilst pretty happy with those results, for whatever reason decided to go fully manual and constantly juggle aperture and shutter speed to suit. Auto ISO is not used. He claims (RAW) exposures need next to no tweaking regarding over/under exposure. Now here's the thing, he says images appear sharper as a result of using manual exposure compared to Av priority.

I said I doubted things being sharper unless he's just using an "on average" faster shutter speed thus reducing any shake. He's been taking football pics for years and should know the minimum shutter speed he can get away with and seems quite convinced of the improvement.

So, sharper images when using manual exposure - is he just fooling himself? The obvious thing is for him to set up a test chart and do an Av priority shot compared to a manual exposure one. Personally, I ain't buying it.

Any thoughts?

Well, I have not read the entire thread, but there could be some truth to his story, problem is, he isn't giving you the whole story. Let's try to fill in the holes. There are three things that control exposure: Shutter, Aperture, ISO. None of these things are "neutral" in their impact to IQ, however. Shutter not only controls the duration of exposure, but also has an impact on the amount of motion blur. Aperture not only controls the quantity of light over time, but also depth of field. ISO not only controls the rate at which the image saturates, but can also exacerbate noise.

In an auto exposure mode, you control ONE of these things (or, in the case of M+Auto ISO, two). Lets say your friend used to use Tv. He could then control shutter, but aperture and ISO are arbitrary factors. Depending on the needs of the scene, even a lens that is sharp at f/2.8 may not be sharp in a deep enough field, so if your shooting in lower light,  you may end up with images that are sharp...in an extremely thin depth around part of your subject. Additionally, you might find that your images are noisier than you might have been able to achieve if you had total control over your exposure settings.

Av mode is similar. Again, you control one factor out of the three, and shutter speed and ISO become arbitrary factors. If you stop down your aperture to achieve the proper depth of field, your shutter might automatically end up too low, increasing motion blur. If you need f/8 for the proper DOF, depending on the capabilities of your camera and how the custom functions are configured, you might end up with a shutter that is MUCH too low, rather than an increase in ISO. You might have a low-noise image, but now you also have blur from camera shake.

Now, before I move on, better cameras, like the 5D III and 1D line, often offer much more configurability with custom functions to guide the camera into making the kinds of choices you would more often, thereby reducing the chance that you might fall into one of the situations where the camera chooses wrong, and your IQ suffers as a result.

There IS an argument for using manual mode to achieve sharper results. When you control every aspect of your exposure, you are also controlling every aspect of IQ. YOU control the shutter speed, and therefor have total control over whether you get motion blur or not. YOU control the aperture, and therefor have total control over whether the entire thickness of your subject is within your DOF. YOU control ISO, and therefor have total control over noise levels.

If your friend was really referring to his ability to exactly choose, via instinct or that natural sense that accumulates along with experience, the right shutter speed, aperture, and ISO to maximize his IQ....then he is absolutely correct. You CAN get sharper images when using manual exposure. The kicker is that you have to have the skill to gauge all the various aspects of your scene and your exposure settings to actually set them right and achieve that maximum level of IQ.

Personally, I use manual exposure mode for my bird and wildlife photography. I used to use Av, but I then I learned a bunch of new things, and I became aware of how to use manual mode properly to maximize IQ, on the fly, without having to actively think about it all that much. It's a technique that kind of comes along with a certain level of experience I think. With birds, I eventually got a sense of what apertures with what lenses I needed to get the right amount of the bird in the DOF, and at what minimum shutter I needed to freeze the bird's motion. I learned the range of ISO settings within which noise was acceptable and controllable in post. You also learn how to use the exposure meter at the bottom of the VF to help you, along with the brightness of various background factors, to gauge what your exposure needs to be (where the marker on the exposure meter SHOULD be pointing in order for exposure to be "correct" for that scene).

Once you reach that point, you don't have to think as much about what your doing when it comes to exposure. You make quick, momentary judgments about where you think the exposure meter indicator should be, what DOF you need, roll some dials, and start taking shots. You also begin to understand that once you set your exposure for a given scene in known lighting, you don't need to change your exposure once it's set. Only when the lighting changes, or you change your scene (i.e. point your lens somewhere else) do you then have to recalculate and choose new settings...but again, that should all happen in a couple of seconds and be done before you really realize you did it.

So, your friend isn't wrong, he just wasn't telling you everything. ;)

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