topic Re: Bower 500mm fixed lens NO AF. in EF & RF Lenses

Bower 500mm fixed lens NO AF.

PhotosByNeva — Thu, 26 Nov 2015 06:12:39 GMT

I have a Canon 6D and my husband got me a 500 mm fixed lens. No autofocus and I want to know what would be the best settings for moon shots. In particular quarter or half moon. I get some good ones and then I get some that are too bright if I use the M setting or P setting. I want to try setting the camera myself. ISO, aperture, etc.

Any suggestions?

Re: Bower 500mm fixed lens NO AF.

RobertTheFat — Thu, 26 Nov 2015 12:32:00 GMT

@PhotosByNeva wrote:
I have a Canon 6D and my husband got me a 500 mm fixed lens. No autofocus and I want to know what would be the best settings for moon shots. In particular quarter or half moon. I get some good ones and then I get some that are too bright if I use the M setting or P setting. I want to try setting the camera myself. ISO, aperture, etc.
Any suggestions?

If it's too bright with the "M" setting, try using the next narrower aperture or the next faster shutter speed; repeat as needed.

If it's too bright with "P", that's a different matter, since "P" uses the camera's built-in light meter to set the exposure for you. The meter is probably getting confused by the dark background. Try changing the metering mode to "Center-weighted Averaging" or "Spot" (i.e., not "Evaluative", which gives the background too much weight).

The fact that the lens lacks autofocus is unrelated to your exposure problem.

Re: Bower 500mm fixed lens NO AF.

ebiggs1 — Thu, 26 Nov 2015 15:26:22 GMT

Lots of interest in 'shooting the Moon'!

You need to learn the Looney 11 Rule. Set aperture to f/11 and shutter speed to the [reciprocal of the] ISO. <---Looney 11 Rule

Next you need to learn how to bracket because this like most photography stuff is just a starting point. Remember it is daytime on the Moon. Even if it is night time where you are.

Do you have the fixed aperture mirror lens or the adjustable aperture refractive lens? If the latter use the Looney Rule as is for starters. If your lens is fixed f8, adjust it by one stop brighter. Example, f11, SS100 and ISO 100 change it to f8, SS 200 and ISO 100.

Of course you need a good tripod.

Actually this lens which is made and branded by several different companies, does a reasonable job with IQ. Essentially similar to the average kit lens. It can be helped even more by a good post editor. BTW, a post editor is essential for good Moon shots.

Re: Bower 500mm fixed lens NO AF.

TCampbell — Thu, 26 Nov 2015 16:03:01 GMT

I'm noticing a lot more interest in astrophotography and lunar photography these days.

I'm aware of two different 500mm lenses with the Bower name on them.

One is basically an acrhomatic lens (like a achromatic refracting telescope) and it does have an aperture adjustment. It's widest aperture is f/8.

The other is a "mirror lens" (basically a Schmidt-Cassegrain design) and it's f/6.3 and it does NOT have an adjustable aperture (it's permanently fixed at f/6.3.)

If you have the f/6.3 "mirror lens" version then that's 1.7 stops brighter than f/11 so you'd need to increase you shutter speed by 1.7 times... instead of using ISO 100 and 1/100th you would use ISO 100 and 1/320th.

If you are using the refractor version of the lens then just stop down to f/11 on the aperture ring and shoot ISO 100 and 1/100th.

If the moon is high in the sky (not just barely rising or setting on the horizon) then you'll nail the exposure. If the moon is at the horizon then it'll likely be dimmer (and orange) so you'll need a longer exposure.

The moon is consistently lit by sunlight. While you could shoot it as a "Sunny 16" rule exposure (the exposure rule for shooting a subject outdoors in bright mid-day sun) what's going against the moon is that it does not have a very reflective surface. Only about 1/8th of the light that hits the moon is reflected. It has the same amount of surface reflectivity (astronomers call this "surface albedo" or just "albedo") as a worn asphalt road. For that reason, the extra stop of light (using f/11 instead of f/16) helps brighten it up so it doesn't seem so dim.

The moon will look better in 1st quarter or 3rd quarter phases (but 3rd quarter moons rise a few hours before sunrise whereas 1st quarter moons don't set until a few hours after dark... so you don't have to set your alarm clock to wake up extra early like you would to shoot a 3rd quarter moon.) This is because the sun is lighting the moon from the side and means the mountains and crater walls cast shadows that really help give the lunar surface a 3-dimensional look (the moon looks like a flat 2d disk if you shoot it at the full moon.)

500mm isn't a lot of focal length to get a detailed shot of the moon -- especially using a full frame sensor camera like your 6D.

Here's an image I took (and posted) quite a while ago, and this image DOES use the "Loony 11" rule. But it's shot using an APS-C size sensor camera (in my case it's a Canon EOS 60Da camera -- my astrophotography camera) and the camera is attached to a TeleVue NP101is quad-element apochromatic refractor telescope (540mm f/5.4 telescope) along with a TeleVue 2x powermate (focal length multiplier) which effectively gives me 1080mm focal length at f/10.8 (close enough to f/11).

The moon is only 1/2º from edge to edge (that's the "angular dimension" -- btw, the moon has an elliptical orbit so the orbital distance varies by about 10% during the lunar month -- but that only changes it's apparent size by a few arc-minutes -- it's still always going to be very close to 1/2º wide.)

With your 500mm lens on a full-frame camera body, the "angular" dimension of your field of view is 4.1º x 2.7º (you can use an angular field of view calculator like this one to determine those values: http://www.tawbaware.com/maxlyons/calc.htm ). That means you would be able to easily fit 5 moon diameters in the vertical dimension (the short dimension) and just over 8 moon widths in the horizontal direction. This wont be a particularly large moon in the image.

If you want a larger moon then you'll need more focal length -- which is why I use a telescope.

Incidentally... there's a story behind the image above. I am involved in a fairly large astronomy club and I'm rather passionate about astronomy, astrophotography, I am also a planetarium operator/presenter, etc. So one day at one of our public observing events, I had a couple that was interested in learning how to photograph the moon. I *happened* to have my camera with me but it wasn't attached to the telescope because I was not planning to do any astrophotography that night.

But since they were looking for advice, I explained the rule and how to know how to set the ideal exposure. With that, I explained the focal ratio of the telesocope was f/5.4 and that I was going to attach the 2x focal length multiplier (bringing the focal ratio to f/10.8 -- close enough to f/11) and therefore we'd just set the camera to take a manual exposure, set the ISO to 100 and set the shutter speed to 1/100th sec. We attached the camera to the telescope, focused, and took ONLY ONE shot. This is that shot.

The point is... if you follow the rule when the moon is high in the sky (not at the horizon where atmosphere will dim it somewhat), you WILL nail the exposure.

Re: Bower 500mm fixed lens NO AF.

PhotosByNeva — Thu, 26 Nov 2015 19:53:58 GMT

but it looks BEST when it is just comin up...in my opinion....especially when it has some cloud streams over it.

Re: Bower 500mm fixed lens NO AF.

Norm53 — Thu, 26 Nov 2015 20:38:49 GMT

Informative thread on astrophotos. Guess I better start refreshing my memory on sky objects so that when I tire of bird shots, I can set my gear outside and shoot there.

Norm

Re: Bower 500mm fixed lens NO AF.

PhotosByNeva — Fri, 27 Nov 2015 04:01:43 GMT

You can't possibly tire of bird shot! It's just not possible in my opinion, I love bird shots. Especially waterfowl

Re: Bower 500mm fixed lens NO AF.

Waddizzle — Fri, 27 Nov 2015 22:24:46 GMT

I've taken a lot of shots of the moon, both looney and otherwise. 🙂 The full moon is a very bright, high contrast object. It fools the light meter in my camera, 6D, into over exposing the image. In other words, if I adjust the shutter so that the exposure indicator is at "0", then the images are always way overexposed.

I have also taken my best shots of the moon in the early evening before the sky becomes fully dark. It is easier to focus on the moon under those conditions, although focusing on a star when it is dark may be what's best.

Because the moon is so bright, a neutral density, ND, filter may help bring out the contrast on the surface. Take a variety of shots a different exposures and/or ISO speeds. Underexposed images tend to come out better. You'd be surprised at just how underexposed you can go, and still be able to render great images in post-processing. Remember, your objective is to capture contrast, just as much as it is to capture focus.

A full moon lacks contrast, shadows in its' craters, so the images do not show much depth. A half moon image will have craters with shadows, creating a sense of depth in the image.

Re: Bower 500mm fixed lens NO AF.

Norm53 — Fri, 27 Nov 2015 23:44:20 GMT

It might be convenient to know where the moon is located (and its phase and appearance) throughout the night to save the time of going outside all the time to check it out. I was just looking at a lunar calendar for Phila., which ought to be close enough for Cape May Court House, NJ. I thought that I could tell from it the moon location, but I don't know how to interpret the data, especially, the degrees. (Arrows below did not copy correctly; first one should point to NW and second one should point to NE, considering north to be at the top of this message.) Lots of other data, including appearance are there. Clicking on the date shows a position graph throughout the night. Could be a useful source if I were smart enough to know how to interpret the data.

http://www.timeanddate.com/moon/usa/philadelphia

Moon Set Moonrise Meridian passing time

8:25 AM

↑ (294°)

6:41 PM

↑ (66°)

1:04 AM

(67.9°)

Norm

Re: Bower 500mm fixed lens NO AF.

TCampbell — Sun, 29 Nov 2015 18:49:30 GMT

As a passionate amateur astronomer, I can generally always tell you where the moon will be or when it will rise & set.

A 1st quarter moon rises at mid-day and sets at mid-night (varying by about an hour a day depending on how many days it is "before" or "after" the 1st quarter).

A full-moon rises at sunset and sets at sunrise. (again... varying by about an hour per day).

A 3rd quarter moon rises around mid-night and sets around mid-day.

A "new" moon rises at and sets with the sun (the moon will appear very near the sun in the sky -- although we are seeing the non-lit side of it so it is very difficult to see.)

Just like the Sun, the stars, and everything else in the sky... the moon "rises" in the east and sets in the west.

If you're framing up the moon by itself, then it's nice to let it climb higher in the sky -- don't shoot it until it's at least 30º above the horizon. The atmosphere will cause distortion -- specifically an effect called "atmospheric dispersion". Any object near the horizon will be distorted by this effect. You would notice a photo of the full moon would have a very slight blue-fringe on one edge and a slight red-fringe on the other edge. This actually causes a blurring of the whole surface and you'll get a sharper image if you fix that. To fix, you'll need a more powerful photo editor like Photoshop. Down in the right where you normally see the layers, click the tab to switch to "channels" then pick one specific channel (such as "red"), click the "move" tool (upper left margin) and then use the arrow keys on your keyboard to move the channel by just 1 pixel, then flip back to "all" channels and see if that was enough to line it back up (unfortunately I don't know of a way to display all channels but move just one or it would be easier to adjust until it's converged.) I usually adjust the "red" channel to bring it in line with the "green" channel and likewise also adjust the "blue" channel to bring it in line with the "green" channel. This will result in a sharper image of the moon by countering the effect of atmospheric dispersion.

If you're shooting a landscape with the full moon in the shot, then it's best to shoot it near moon-rise AND it's also best to shoot it at least ONE DAY BEFORE the day of the full moon (the moon will still look "full") This is because as the moon rises, the basckground sky will still be dusky blue and you'll be able to see the foreground (it wont be dark.)

There are two apps (that work on smartphones) that you might want to have to help with planning.

One is "The Photographers Ephemeris" and the other is called "Sun Surveyor" (which also does the moon).

Both work similarly in that you set the date & time when you'd like to shoot. They will tell you the position where the sun and moon will be in the sky AND they'll overlay that onto a Google Map.

Suppose I want a photo fo the moon rising over a particular mountain peak. I can use the tool to show the point where the moon will rise (and the path it will take across the sky). I can point a spot on the map and it'll show me the relative angle to the moon or sun. I can then MOVE that spot on the map until that line passes over that mountain that I want in my shot... and basically you are using the tool to show you where you'll need to stand and wait for the moonrise if you want the moon to be framed exactly where you want it for your shot.

I use Sun Surveyor on my iPhone... but only because "The Photographer's Emphemeris" was only available as a desktop app (Java client) and they didn't have a mobile phone version (even though they were first). So I ended up going with Sun Surveyor because they were "the only thing that did this" at the time. Now the folks who wrote "The Photographer's Ephemeris" have ported it to mobile phones and smart devices (iPads, etc.)

Here's a sample...

I live in Dearborn, MI -- the hometown of Henry Ford. At the Henry Ford Estate (Henry Ford called it "Fair Lane" -- sound familiar?) Henry Ford had a meadow cut through the trees to produce a view of the sunset and on the day of the summer solstice, the sun would set exactly between the trees as viewed from his back patio.

So here's the image of the software (Sun Surveyor running on my iPad) set to that date. I have the time set to 8:54pm and at this time the sun is still 2º above the horizon (it doesn't set until 9:13pm on this day). But I can see the exact position of the sun from the back-patio of the estate.

See the image here:

Using this, I was able to plan to get this shot:

My screen shot is from the "Sun Surveyor" app running on my iPad, but "The Photographer's Ephemeris" is the first program I knew of that did this (they just didn't have a mobile version at the time - but they do now) and they do pretty much the same thing.

Either is ideal to help you figure out "when" and "where" you need to stand if you want to get the moon (or sun) at a specific spot in your images relatively to a foreground landscape feature on Earth.

"Ephemeris" is what astronomers call the orbital data that we use to calculate the position of solar system objects (all objects in orbit have "ephemeris" data which determines the shape, angles, etc. of the object in orbit around another body.)

The folks who write "The Photographer's Ephemeris" also have an app named "The Photographer's Transit". This app works similarly to "The Photographer's Ephemeris" but it's intended for owners of interchangle lens cameras (like DSLRs) and it calculates the size of the field of view based on your camera and lens. That means that rather than just drawing a line on a map showing where the sun or moon will be from your position, it draws a triangle shaded region on the map showing you everything that will be within the field of view of your camera based on where you are standing and the camera and lens you are using to take the shot. In other words it helps you plan your composition.

Re: Bower 500mm fixed lens NO AF.

Norm53 — Sun, 29 Nov 2015 20:44:07 GMT

The folks who write "The Photographer's Ephemeris" also have an app named "The Photographer's Transit".

Fantastic shot!

Just took a look at the blurbs about both of the above products online. Seems that they are free, which seems like a fair price to me. They are also available for PC, which is good for me because I am the only person in a developed country who still doesn't have an iPhone.

Most of this subject is over my head, but I'll get tutored somehow later. I'm still studying the basics of our solar system; that is, how the earth, moon and sun work together throughout the year.

Norm

PS. Through more online research, I finally figured out how the app that I posted earlier works. However, it would seem that the above s/w's are more germane.

Re: Bower 500mm fixed lens NO AF.

Norm53 — Sun, 29 Nov 2015 20:48:43 GMT

Addendum: Since you are an astrophotography aficionado, I suppose that you also use a telescope w/camera from time to time. If so, must you buy a separate tripod and head, or will those used for zoom lens w/camera do?

Norm

Re: Bower 500mm fixed lens NO AF.

TCampbell — Sun, 29 Nov 2015 23:08:17 GMT

@Norm53 wrote:

Just took a look at the blurbs about both of the above products online. Seems that they are free, which seems like a fair price to me. They are also available for PC, which is good for me because I am the only person in a developed country who still doesn't have an iPhone.

I know you can get "The Photographer's Ephemeris" on a PC and that is free (last I checked it's a Java application ... which means it'll run on any computer -- Windows, Mac, even Linux.

But when I checked the price of the smart-phone app... that was not free. (e.g. Photographer's Ephemeris was $8.99 -- or you could get the "Photographer's Ephemeris" and "Photographer's Transit" bundle for something like $12 (that's from memory -- so I might be off on that price.)

Re: Bower 500mm fixed lens NO AF.

Norm53 — Sun, 29 Nov 2015 23:22:34 GMT

Might have been a free trial offer. Anyway, the prices won't break the bank.

Norm

Re: Bower 500mm fixed lens NO AF.

TCampbell — Sun, 29 Nov 2015 23:27:24 GMT

@Norm53 wrote:
Addendum: Since you are an astrophotography aficionado, I suppose that you also use a telescope w/camera from time to time. If so, must you buy a separate tripod and head, or will those used for zoom lens w/camera do?

Norm

So there are two different answers to this question.

I do attach the camera to a telescope and MOST of the time that's what I'm doing. But all of the telescopes I use are either on something called (generically) an "equatorial" mount (meaning that the axis of rotation is aligned so that it is parallel to Earth's axis of rotation -- roughly the north star although that star is technically about 2/3rds of a degree away from the true pole.) If the mount is not precisely aligned then the stars will all seem to "drift" in the field of view very slowly. Visually you will think things are not drifting... but when you use a camera to take an exposure merely a couple of minutes long you'll notice everythign is smeared from the drift caused by an imprecise alignment.

Normally even if a mount is precisely aligned, there is enough mechanical error that your tracking wont be smooth enough to have no blur in the image. Variations in how perfect the worm gear is made... or imperfect orthagonality of the mechanical axes of the scope, etc. will cause some grief even when you align "perfectly". To get around this problem, astronomers use soemthing called an "auto-guider". It's a 2nd camera mounted on the telescope and all it does it take a photo of the same area of the sky... but every few seconds (whereas the main imaging camera might be recording an image for many many minutes... 5 minutes, 10 minutes... it could be as much as an hour.) But the auto-guider isn't trying to find faint detail in a deep-space object... it just wants to track the position of a reasonably bright star that would easily expose within a second. It compares the position of that star in the frame from the original position to detect if the star has drifted (even by a tiny amount). If it has drifted, then it sends a corrective movement to the telescope mount to put the telescope back on track. It does this continuously and at the end of a very long image the object you want to photograph will not have moved by even so much as 1/2 of a pixel.

So the first answer is that I'm using telescope mounts. My "favorite" mount is my Losmdandy G11 which has, so far, given me staggeringly good results. So far I've managed 8 minutes "un-guided" imaging with nearly no perceptable drift (it's rare to be able to go much longer than 4 or 5 minutes but my mount.) I know about a half dozen other astro-imagers that use the same mount and their mounts (while good) aren't able to get away with unguided images as long as me (so I appear to have won the proverbial lottery and happened to get a copy of that mount which has better-than-typical performance.)

But there is a second answer... which is that I did recently acquire a special "head" which attaches to a photographic tripod and allows me to use a regular camera and lens and not need a telescope. This means I'm getting wider field images (instead of imaging one particular deep space object I'm imaging a larger area of the sky... perhpas big enough to hold an entire constellation ... perhaps big enough to occupy quite a huge area of sky (Milky Way images, etc.) I've only recently acquired it and haven't put it to work (yet ... but it's coming with me on a trip in January and I expect it'll get heavy use.)

That system (the Losmandy StarLapse) does go onto a normal camera tripod but you want a "beefy" tripod (nothing too springy or flexible -- you're trying to eliminate vibrations). Also, while it could be mounted to my normal head (I use a Benro BH3 ballhead), it's much easier to attain precise polar alignment with a video head. I have a Benro S8 head and a Benro S4 video head (the S8 head is much stronger but I think the S4 head may do the job.)

If the load is not too heavy (smaller lenses) then you can get away with lighter solutions -- such as a Vixen Polarie or iOptrion Sky Tracker. I prefer the Losmandy (not an assembly line product... these are built in a machine shop one at a time... which drives up the price, but the precision of the product is so much better.

I've mentioned this elsewhere... you don't necessarily need a head that "tracks" the stars to do astrophotography. If you want landscape in the foreground then a stationary head is better BUT you want a very wide angle lens. For a camera with an APS-C size sensor, divide 375 (that's your baseline) by the focal length of your lens (e.g. if you have a 10-22mm ultra-wide angle zoom for example but you're using the 10mm focal length) then you'd divide 375 ÷ 10 = 37.5 and that result is the number of seconds that you can leave the camera shutter open and NOT get elongated stars due to the rotation of the Earth.

Re: Bower 500mm fixed lens NO AF.

Norm53 — Mon, 30 Nov 2015 01:24:11 GMT

But there is a second answer... which is that I did recently acquire a special "head" which attaches to a photographic tripod and allows me to use a regular camera and lens and not need a telescope.

Getting back to the moon, does a telescope w/camera on a photo tripod (with appropriate head) produce moon images that a zoom lens w/camera on that tripod (with appropriate head) cannot produce?

Norm

Re: Bower 500mm fixed lens NO AF.

TCampbell — Mon, 30 Nov 2015 01:40:52 GMT

@Norm53 wrote:
But there is a second answer... which is that I did recently acquire a special "head" which attaches to a photographic tripod and allows me to use a regular camera and lens and not need a telescope.

Getting back to the moon, does a telescope w/camera on a photo tripod (with appropriate head) produce moon images that a zoom lens w/camera on that tripod (with appropriate head) cannot produce?

Norm

Yes - it's more to the "angle of view"

The moon has an "angular dimesion" of about 1/2º from edge to edge.

If you take a photo of the moon with a 300mm lens on a camera with an APS-C sensor ... you can use this page to find the angular field of view: http://www.tawbaware.com/maxlyons/calc.htm

If you scroll down to where it says "Angular Field of View Calculator" you can plug in the values "300" for focal length, "1.6" for crop factor (the default) and leave the aspect ratio at 3:2 (the default for any DSLR) the click "compute" you'll see the angles.

The horizontal angular field of view is 4.3º

The vertical angular field of view is 2.9º

Knowing that the moon is only 1/2 degree you can quickly see how you can fit nearly 6 moons in the "short" dimension of your field of view and and just over 8 mooons in the "long" dimension. This means you are going to have a rather tiny moon.

If you want a large moon that fills the frame, you'll need something around 1200mm (the moon shots you've seen me posts were taken through a telescope at 1080mm and I cropped just a tiny amount.) This really helps when you want to see detail.

The loony 11 rule still works... so if it's an f/11 scope then it's ISO 100 and 1/100th sec exposure. It'd probably shoot it at a much faster ISO and faster shutter speed if on a mount that isn't tracking the skies. Otherwise a "tracking" mount is preferred. Since the exposure time is short, it doesn't put great demands on the quality of the mount. When you shoot long exposures (e.g. 30 seconds or longer) that's when investing in a better mount really pays off.

The longer the exposure and the smaller the area of the sky that you image, then the mount needs to be better (short exosures are more forgiving and wider field images are more forgiving. I recommend starting with those. Very long and very narrow field of view images are the hardest (and have the greatest demands on a very good tracking system to keep the telescope on target during the entire length of the exposure.)

Re: Bower 500mm fixed lens NO AF.

PhotosByNeva — Mon, 30 Nov 2015 02:11:16 GMT

It's funny, but i just grabbed it one night and the full moon was coming up and took some really cool pictures! It was very detailed and like you said underexposed. I was even holding it by hand and was amazed that they came out pretty clear.

Re: Bower 500mm fixed lens NO AF.

Norm53 — Mon, 30 Nov 2015 07:48:23 GMT

Thank you, Tim, for your inspiring presentations.

Norm

Re: Bower 500mm fixed lens NO AF.

ebiggs1 — Mon, 30 Nov 2015 14:41:50 GMT

"It was very detailed and like you said underexposed."

Underexposure is much better to deal with in post than overexposure. Especially if you shoot RAW and not jpg.