How to have sharp images?

Swame_sp

I'm not trying to pixel peep the image, but while putting it up on my 24" screen, felt that image was not sharp. It's a tokina ultra wide angle lens. I was in Ottawa for a short trip and had a chance to capture this image near the science museum. It was one of the coldest nights when I was lugging around a tripod (my friend's) with 2 layers of gloves and 4 layers on me, would have been frost bitten if I had spent another hour outside.

The image in question is below.

Settings:
Body - D7000
Lens - Tokina 12-24f/4
Settings - ISO 160/f20/15s/24mm/1.3eV



Does the lens has to be sent for fix or is it just working fine? Thanks!!

KnockKnock

Well, if that's no typo, I'd say you're losing a lot of detail by shooting at f/20. The world has changed a lot since Group f/64. With the D7000 (@16MP, I think things start to get blurrier at around f/11 due to diffraction. Also the likelihood of blurriness due to camera shake is higher at a 15s exposure.

I suppose you're going for depth of field or the starburst effect, but you'd probably be sharper shooting ISO 640 / f8 / 5s or somewhere around there. Make sure you weigh down the tripod as much as possible to stabilize it. I'm sure other more-experts will chime in, but I hope that helps.

Ironheart

It would be nice to have a link to a full size or at least 2000px to examine. Also 15 seconds is a long exposure with potential for vibration. Was it windy?

TaoTeJared

Image is way too small to tell.

We just went though this with somone else's lens: http://forum.nikonrumors.com/discussion/266/is-my-16-35-a-bad-copy#Item_21

Your settings are close enough to their's that many of the same comments apply here.

Elvishefer

I once messed up some shots because I was shooting with a tripod on snow, and the snow slowly compacted over the long exposure and moved the camera.

Swame_sp

Bigger version of the image

It was a bit windy but the tripod was not extended, just on normal height. It was placed on the road with snow about 1 feet away, i mean it was relatively on a stable ground.

Ironheart

The 1024x678 image is only slightly more useful. Even a small amount of wind can push a camera around on a tripod. One way to see this is to use maximum zoom with live view. You'd be surprised at how much movement there really is. I'd have probably pushed the ISO and shortened the exposure. Also everyone else's comment about f/20 and diffraction; you would get an even shorter exposure if you opened up the lens a bit.

What I'm trying to see (and you would need the original at highest res to see this) is if all of the details are blurred from movement or if it is a missed focus, or what... Anyway, I still think it is a cool photo, if a bit dark :-)

Edit: Oh and as is mentioned on the other thread, zoom lenses are never sharpest at max or min, so backing off of that will usually sharpen things up a bit too.

DJBee49

In the 'olden days', we used to use the lens cap to make long exposures. Now before you fall about laughing, here are the advantages.

Whatever camera you are using, you lock the shutter open (and mirror up) with the lens cap on (or another cover of some sort over the lens), make the exposure, cover the lens up and then close the shutter. On a tripod obviously- although you can do it with the camera perched on a wall for instance.

Why would you do this? Well, you can build the exposure up in segments. Say a car, gust of wind or person gets in the way, you cover the lens until the impediment has gone away and then just build the exposure up to the required time by uncovering the lens again. If you are locking everything open there is no shutter or mirror vibration as long as you do not jog the camera. You can even shade during the exposure with a black card for part of the exposure (the sky for instance), 'paint' with flash or incandescent lighting and you can perform time tricks by moving things around during the exposure. This all works best with exposures longer than about 5 seconds but is lots of fun! To get there you will need to use low ISOs and possibly ND filters unless it is really dark.

Slightly off-piste, but I am going to do some experiments using pin-holes in place of lenses on digital cameras. I have experience with this on film but not digital. Has anyone done this?

I said 'in the olden days' but I still use these techniques with digital cameras. In fact they work even better because you don't have to worry about reciprocity failure any more! >:D<

safyre

For crop sensor cameras, the most optimal sharpness is between f/8-f/11. After that, diffraction begins to set in. If you open up your camera to f/11, you will also decrease your shutter speed by almost 1/4th which also helps in giving there less of a window for external issues like wind, etc.

Msmoto

@ DJBee49

I love this. I used to use a paddle covered with black velvet. Exposures of up to 45 seconds with transparency material. 2 1/4 format or larger... I think this is still the best way to do long exposures and to have about twenty pounds of weight hanging on the tripod. I have also used two tripods outside with long lenses which have a foot.

KnockKnock

Hah.... sounds like darkroom techniques in the field. Next thing we'll be dodging and burning... the sensor.

TaoTeJared

As Ironheart said the image is too small for us to see any real detail. From what I can tell it looks as sharp as you could get it. All exposures over 1/100sec can be prone to a bit of shake. I remember taking photos from an overpass and what little the road shook still showed in the photos. Any long exposures I generally try to take a handful since even the slightest movement can knock off details.

DJBee49

Msmoto
Perhaps getting slightly off topic (again) but ....
Much of the large format work I have undertaken was without ever using the shutters (except for the 'T' setting of course)! Open flash in the studio and long time exposures for ambient light using lens caps or cards, mostly at f45 to f90. I agree, I think this is still much the best method for long time exposures. Nice and simple!

KnockKnock.
You are right, It is pretty much the same! Shading during exposures is very effective- lowering the exposure from things like bright street lights, balancing sunset skies with the landscape, even windows in interiors using dodgers! Sometimes a bit hit and miss but can be very effective and the looks on the faces of observers is almost worth the effort on its own!

Msmoto

@ DJBee49
This thread is basically about how to get sharp images with long exposures. So, a discussion of the large view cameras is fine. Some of the folks may have never even seen an 11" x 14" Deardorf on a 12 foot high stand. A lot of the lessons learned in the old days...1960's and forward, are still quite true today. However, the lenses in the old days were f/5.6 or f/8 wide open, so when the f/stop is discussed, the important point to remember is these were designed to be used at f/45 or f/90. Or,5 stops down from f/8 to f/45. Thus an f/1.4 would be at f/8 or f/11 but not smaller for optimum performance.

Some who read this might be amazed as to how things were done a long time ago, but these basic lessons we learned are so important today. And the FPS....ha, ha, ha...like one shot per three minutes....

DJBee49

Interestingly, not really that long ago....I was shooting 4X5 transparencies using all this stuff six or seven years ago. Not sure what I would be doing now if I was still working- a digital back perhaps? They are stunningly expensive though. It has occurred to me to buy one for my much loved (and unused) Horseman but far too expensive for an amateur indulgence I am afraid. I have quite enough guilt running my present Nikon gear as an expensive hobby!

I never got as fast as one shot every three minutes!

MikeGunter

Hi,

You can do it digitally with your Nikon cameras, too. There are provisions for multiple exposures, and you can define how many exposures and use a matte box for layering the exposures for a complete composite in camera.

For the folks who want and yearn for the slowness of film, this would the perfect and quite accurate exercise. :-)

The result would eliminate the use of Photoshop, which I find my essential friend.

My best to all,

Mike

DJBee49

Not sure about the yearning for the slowness of film but I admit to sometimes struggling with all the complexities of modern gear! Too many buttons!
I seem to like simple equipment and techniques where possible and admit that there are many tricks I have yet to learn, including the one Mike mentions above. I also marvel at the extraordinary capabilities of digital equipment and love Lightroom and Photoshop, although I use the latter very little now, finding that LR does almost everything I need.

MikeGunter

Hi DJBee49,

BPH (before Photoshop), one could have their Nikon pin registered (primarily for animation work), but also for making multiple exposures.

I had a Nikon F2 Pin Registered for that as well as a F3 later.

With either one, you shoot a subject - say a roll of 'moons' in a specific location, then rewind the film leaving the tongue out. Having marked the film (you have know where the take up is, of course), begin to start again. With a precise record of each frame from the first round of exposures, you add the second round of exposures.

Naturally, you can do this a third or fourth time.

The catch is that film will expose at what it will expose at. The additive exposures will overexpose if given too much exposure - too much light is too much light. You have to account for the total amount of exposure for each frame.

Digital makes all of this much simpler with Photoshop and layers. It is the same thing, only easier using the layers menu, and adjusting accordingly and you can actually see what you're doing as you're doing it. ;-)

My best,

Mike

spraynpray

+1 DJBee

JJ_SO

Very long exposures with a lens cap (or a real cap/hat - even better, because you don't need to touch lens or camera) eat batteries and heat sensors, just a reminder. But your input, DJBee49, is great - I'll try that, too.

As for the original, hrrmm, post, I'd like to add: If it is windy, a 20 pound weight hanging under the tripod will swing in wind (and animates the tripod as well) if it is a photobag. I rarely carry bars of lead or sandbags with me. In the mountains, cold weather and planning a panoramic starburst shot, I read one photog who puts the tripod to the place and freezed the tips of the legs to the ground with water. So the only movement would be the flow of the glacier

A reason for blurred shots can also be a factory with punching machinery closeby or a subway below the street. Or some accidental touching of the lenses focus ring. Actually, so many things can go wrong :-? you better shoot in daylight 8->

Msmoto

Actually, twenty pounds of weight in sandbags, of which I have 60 pounds total, do not swing in the wind. I have used this to stabilize the tripod when shooting long lenses, just so the tripod does not blow over in the wind. (Think 400mm f/2.8 and longer)

In a wind more than 20-25 mph, nothing will stabilize the tripod as the issue of resonant frequency becomes a very real problem. If you hear the wind whistling around the tripod, it just may be too windy to be out taking photos.

One other trick I have done is to carefully place the sand bag over the top of the camera/lens. Of course one wants this centered over the tripod support so as to not place the camera/lens in a bind. And, the remote function may have to be used if you cover the controls on top.

JJ_SO

And the sandbags have to be very tight (? meaning not dispensing sand grains), if you place them on top. I used my photobag for this which is also 20 pounds on some days. But when shooting, some of these weight is on top of the tripod and the rest becomes to lightweight and is swinging in the wind. Should've known that photogs use to carry 60 pounds of sand... /:) And I thought if I write an advice like "in case your shooting in less cold areas you can bring your concrete mixer and build a nice solid column" I probably approach the border of getting warned because OT... ">

tcole1983

And the sandbags have to be very tight (? meaning not dispensing sand grains), if you place them on top. I used my photobag for this which is also 20 pounds on some days. But when shooting, some of these weight is on top of the tripod and the rest becomes to lightweight and is swinging in the wind. Should've known that photogs use to carry 60 pounds of sand... /:) And I thought if I write an advice like "in case your shooting in less cold areas you can bring your concrete mixer and build a nice solid column" I probably approach the border of getting warned because OT... ">

You are being somewhat ridiculous I believe. What most are pointing out is you want the camera as stable as possible especially if you are going to do a long exposure. In msmoto's case a D4 with a huge lens needs much more to keep it in place then the normal camera and little lens. I think in most cases a good sturdy tripod is more then sufficient. As your exposure length increases though you have more chances for vibration and movement and it becomes more crucial to have a steady base for the camera.

JJ_SO

You're right, I had an attack of half being seriously and half being joking, sorry. I hoped readers would realize that.
Now, there are two extremes with long time exposures: Vibrations while exposing let end up the picture blurred. But exposing long enough will equalize some initial movement (like shutter vibration) if there's not more vibration during exposure. I mean, shortening the shutter speed does not necessarily lead to sharper pictures. If the tripod - head - camera - lens combination doesn't fit together, it always will be a second best result.

And as for the sandbags: I spend some time trying to clean two or three sandgrains out of a leg lock of my tripod. The idea of laying a sandbag over the lens and body is clearly clever, but if the bag has tiny holes...

DJBee49

Mike.

Aaah! Happy memories of fiddling with multiple exposures on 35mm cameras this way. Lots of fun and with care it worked well. I seem to remember working out a reasonably accurate facsimile of this by measuring the rotation of the rewind handle to get back to the shot frame again for subsequent exposures without having to mark up the film. I also used to tape the film with masking tape in camera and cock the shutter with the rewind button pushed in so the film did not move. You could then expose again on the same frame as many times as you wished. All of this, of course, is MUCH easier with a 4X5 (or bigger) view camera where you can draw a visual on the screen for positioning.

I once had to produce some advertising/publicity shots for a pupeteer and rather than do the usual static image of him hugging his puppets or something, we decided to produce an animation in one frame. I shot on 120 B&W and used a bicycle wheel spinning with a light shining through it (a 2K fresnel spot). The bicycle wheel was blanked out with black card except for a 30 degree (I think) segment and the result was a strobe with enough light coming through to make some decent exposures. After much experimentation with rotation speed, lighting angles, number of frames shot, speed of movement of the pupeteer etc. we did the shoot and it all worked miraculously well! The final images had about 6 or 8 exposures per frame. The pupeteer was delighted and we ended up with some beautiful images of him manipulating the puppets as multiple exposure animations. They were good enough to end up as 20X24" prints for front of house amongst other uses. Lovely!

For the record, I did not have fast recycling studio (or other) electronic flash units then, stage strobes (I don't mean the US studio electronic flash brand here) were too expensive or too dim (I tried one) and my Mamiya 645 did not shoot at 6FPS or whatever! We considered shooting on 35mm with a motor-drive but would have had to hire one, there would not have been the fine control and I wanted better quality than 35mm anyway. Once again, all shot in a blacked-out studio with lens cap exposures bless 'em (this is my justification for including this story in this thread Msmoto!) ! One of my students did the bicycle rotations for me and I immediately processed the film (we could not wait) to see the results! We then all trooped off to the pub to celebrate our Heath-Robinson triumph over adversity!

Of course, I would not do it this way now (although I just might, to be perverse!) and with our new all-singing-all-dancing digital cameras, it would not be too difficult. Anyone seeing the images now would, of course, dismiss them as 'just done on a computer'.

Would it be as much fun on digital using all our current tricks and would we go off to the pub afterwards and get gloriously drunk in celebration? Hmmmmm, I wonder!

Msmoto

About the sandbags....I first place the sand in a plastic bag....we call them ZipLock or some bag which seals. Then the bag goes into a second plastic bag, finally into the canvas or other sandbag which has its own sealing system. I have no little grains of sand coming out anywhere. Sand is a disaster...