SLRs: taking sharp pictures - DPChallenge Forums

Canon EF-S 60mm f/2.8 Macro USM

04/07/2003 01:41:35 PM · #1

Okay, so I have my lovely D60 and have some questions on how to go about getting the crispest landscape shots from it. Now I realise that the lens plays a large part in this, but in terms of camera technique.

I'm using a pretty solid tripod and I'm using the built in timer to trip the shutter, but the questions I have are:

Should I stop the lens down as much as possible, or use it one or two stops down from the smallest aperture ?

I'm focusing about one third into the 'depth' of the scene to get the hyperfocal distance correctly - is this the way to do it ?

Mirror lock-up - should I use that with the timer ? Is it going to help eliminate the vibrations if I use the mirror lock-up function with the timer ?

Should I cover the eye hole in the camera to minimise any reflections/ light scatter ?

Should I get a remote and use that as a shutter release, rather than using the timer function ?

Comments/ suggestions really welcome.

dadas115

Canon EOS-1000D Rebel XS

04/07/2003 02:14:07 PM · #2

I get my best results with the camera on a sturdy tripod (obviously) and usually stop down to around f/8 or f/11. I usually use the 24mm T/S-E but have had good results with the 16-35 and the 20mm f/2.8. I always shoot these in RAW mode and usually manually focus. Also it might help to bracket the exposure (I usually do +/- 2/3 stop). I always use the miror-lock-up function. You can use it with the timer but I usually use the wired cable release. You should not need to cover up the viewfinder (I believe the miror does a good job of blocking light coming from that direction). It might not be a bad idea to use a gray card to set the WB, and depending on the situation the exposure also.

Greg

scab-lab

Canon EOS-D60

04/07/2003 02:25:13 PM · #3

Just to add one note, definately get the cable release. You will also appreciate it for your macro work . Probally the best accessory that I got for the D60 so far.

Patella

Canon EOS-500D Rebel T1i

04/07/2003 02:28:41 PM · #4

I'm going to address the questions that (I think) I know the answers to -- for the rest, I'll be interested in seeing what people have to say.

Smallest aperture = greatest depth of field = more things "in focus", but obviously you seem to have read something that suggests opening it up a bit -- I'm very curious about this one.

Hyperfocal distance question all depends on what you're trying to shoot and have be in focus in the shot. But I'm sure you know this already so I won't belabor the point. I'd just check on the hyperfocal distance information that comes with the particular lens you're using to shoot with.

Definitely lock up the mirror, if you don't I'm fairly certain that even with the timer the thing still has to flip up for the shot, causing the camera to vibrate and creating that itty bit of blur.

I would personally cover the eyehole, but that's based on some personal experience with the E-20N and I was NOT locking up the mirror, so I can't say for certain. All I know is there's nothing more frustrating than looking at your shots and having them all "light leaked."

Love the "digital" remote that you can get to go with the E-20N. Since it's electronic, there aren't any moving pieces attached to the camera at all, which means absolutely no motion -- unless you yank on the thing and draw the cable tight... As far as whether or not it's better than the timer -- the advantage is being able to shoot a little bit faster since you don't have to wait the 30 seconds or whatever for the timer to trip the shutter each time -- not to mention the time spent setting up the timer. Not hugely important -- but sometimes that gorgeous sunrise/sunset light on the mountain changes quicker than you'd like it to so every second counts in terms of getting additional shots.

magnetic9999

Canon EOS-20D

Sigma 24-70mm f/2.8 EX Aspherical DF for Canon

04/07/2003 02:32:16 PM · #5

you seem to have most of the bases covered.

can you post an image that reflects what you perceive as an unsatisfactory result?

have you used a good quality wide or wide-ish lens on a landscape yet?

Nikon AF-S DX Zoom-Nikkor 16-85 f/3.5-5.6G ED VR

04/07/2003 02:43:28 PM · #6

Originally posted by Patella:

Smallest aperture == greatest depth of field, but only to a certain point. With an increasingly smaller aperture you start to get defraction effects which can reduce sharpness. (at least this is why I'm asking these questions to confirm or deny this kind of stuff)

Covering the eye-hole - the D60 strap comes with an eye-piece cover, which is supposed to minimise light leakage, just wondering when/ if I should use it, as I pretty quickly removed the huge 'Canon Digital - come steal me' advert from around my neck.

Patella

Canon EOS-500D Rebel T1i

04/07/2003 02:44:56 PM · #7

Originally posted by Gordon:

as I pretty quickly removed the huge 'Canon Digital - come steal me' advert from around my neck.

LOL

scab-lab

Canon EOS-D60

04/07/2003 02:51:53 PM · #8

//www.kenrockwell.com/tech/focus.htm

This article explains how to figure the sharpest aperture to use for your lens. (Smallest is not always the sharpest) Gordon, you may want to cover the eyepiece when doing nightime long exposures to keep stray light out. At least, thats the only time I worry about it.

rcrawford

Nikon D300

04/07/2003 02:58:46 PM · #9

I'm not an optical engineer but I do work on systems used to pattern microchips (Hopefully we made the processor in your computer:-)). From these systems I have learned that there is a trade off with respect to aperture. Wider apertures give a shallower DOF but collect more information from the scene. Narrower apertures give a greater DOF but you sacrifice detail. We are constantly fighting this because of course we need as much detail as possible but then the wafer must be in precise focus. To put numbers to it, our system has a numerical aperture of 0.55 but the DOF is less than a micron.

Every lens has its sweet spot where you get the most DOF and still capture reasonable detail. On the E-20 it is around f5.0 to f5.6

dadas115

Canon EOS-1000D Rebel XS

Canon EF-S 60mm f/2.8 Macro USM

04/07/2003 03:17:37 PM · #10

I would suggest going out and doing some tests. I did some in my house with my different lenses using a newspaper taped to a wall and the camera at a 45 degree angle to the wall. I ran through the range of aperture settings and definately noticed that most of my lenses are softer wide open then they reach their optimal sharpness about 2 stops smaller than wide open then around f/16 they start to lose sharpness again. For this reason I don't usually use smaller apertures than f/11 unless I really need them to get more DOF (usually for macro). You can do a test for miror lock-up as well. Put the lens you want to use one the camera and take 3 pictures using the timer and miror lock-up and 3 without. See if you can see a difference. If you can then maybe you should invest in the cable release. I suggest you do similar tests for each parameter and decide which set of conditions work best for you. I actually did run through all of these sorts of test and I was quite surprised that all of these effects do actually affect my final picture.

Greg

04/07/2003 03:27:30 PM · #11

extremely good advice on the testing front - I think I'll be doing some of that this evening.

I also found www.dofmaster.com which I'm going to try out as well as some useful articles - thanks!

Canon EF 70-200mm f/4.0L USM

04/07/2003 10:28:22 PM · #12

Originally posted by Gordon:

extremely good advice on the testing front - I think I'll be doing some of that this evening.

I also found www.dofmaster.com which I'm going to try out as well as some useful articles - thanks!

So after some testing I've managed to learn quite a bit. Think I've been spoiled using a small digicam like the G2 with such wide DoF. Very educational half hour spent. Some more practice needed I think!

paganini

Canon EOS-1D Mark II

04/12/2003 01:04:24 AM · #13

The F number selection (max) is dependent on the lens. There are two issues:

1. Diffraction from lens (and this usually means not more than F16)
2. Quality of the image. On most lenses the optimal point is F8 as it sits in the middle, you sacrifice clarity for greater DOF.

So essentially F22 usually gives somewhat crappy results, especially on DSLR with a big crop factor (think of it as lens coverage, i.e. you're forced to resolve MORE within a given lens than a full frame). F16 is max of what i'd use and if I can help it, i'd like to stay between F8 and F11. If you want as close as possible to infinity to be in focus, then you have to set it up high and trade some image quality for the greater DOF. This won't matter for small prints, but for large prints you can actually see it.

Hyperfocal length varies based on the aperature + the lens. Goto //www.dofmaster.com and select the ONLINE aperature thing and you can see it for the Canon D60's hyperfocal length @ a given Fstop + focal length. Then you'd set it manually. It's not always 1/3 from the scene, it depends on the aperature. On the G2 for example @ F8 @ 7 mm (the wide angle, forgot the exact number), the hyper focal length is 1.2 meters or something :) which means 0.6 meters to infinity is in focus.

As far as TIMER goes, the only issue with timer is that the exposure calculation isn't taken until the shutter is hit unless you lock it or use manual.

Mirror lock up is essential with large DOF AND slow shutter speed (tiny circle of confusion) -- not so important with smaller DOF, but definitely essential between 1/4 second to 1/30 second exposures. If you're doing night shots, it's not so bad if you're going for 15 second exposure because the vibration from the mirror pales in comparison to the exposure time.

As long as you have your eyes stuck to the viewfinder, no need to use the eye piece cover. I think for night shots where you have bright lights behind the lens might be essential if the exposure time is long, or if you want to count number of HOT pixels :)

Originally posted by Gordon:

Originally posted by Patella:
I'm going to address the questions that (I think) I know the answers to -- for the rest, I'll be interested in seeing what people have to say.

Smallest aperture = greatest depth of field = more things "in focus", but obviously you seem to have read something that suggests opening it up a bit -- I'm very curious about this one.

I would personally cover the eyehole, but that's based on some personal experience with the E-20N and I was NOT locking up the mirror, so I can't say for certain. All I know is there's nothing more frustrating than looking at your shots and having them all "light leaked."

Smallest aperture == greatest depth of field, but only to a certain point. With an increasingly smaller aperture you start to get defraction effects which can reduce sharpness. (at least this is why I'm asking these questions to confirm or deny this kind of stuff)

Covering the eye-hole - the D60 strap comes with an eye-piece cover, which is supposed to minimise light leakage, just wondering when/ if I should use it, as I pretty quickly removed the huge 'Canon Digital - come steal me' advert from around my neck.

Message edited by author 2003-04-12 01:33:36.

paganini

Canon EOS-1D Mark II

Canon EF 70-200mm f/4.0L USM

04/12/2003 01:10:14 AM · #14

For lens info, goto:

Photodo

They list the MTF graphs for various different manufacturers. And if you look at a lot of them, usually, F8 is the most optimal point :)
(Hence there are lots of photography clubs with F8 as their name,FYI...)

Canon EF 70-200mm f/4.0L USM

04/12/2003 12:40:22 PM · #15

Originally posted by paganini:

It's not always 1/3 from the scene, it depends on the aperature.

Lots of other good content - but on this 1/3rd in thing - I think I understand it better now. Optically the DoF is 1/3rd in front of the focal point and 2/3rds behind so, in general as a rule of thumb, if you focus one third into the 'depth' of the scene you'll get reasonably good DoF, with most of what you want in focus.

At the hyperfocal distance it's the same - acceptable focus starts half way between the camera and the focus point, and 2/3rds behind it, although that '2/3rds' goes to infinity hence it sort of breaks down a bit :)

The other nasty thing about using very small apertures is that is increases the amount of visible dust/noise in your images. For the brave at heart, try this. Stop your lens down to about f/22, take a shot of the sky or a white wall, and overexpose by about 1 and 1/2 stops. Load it up into photoshop and do an 'auto-levels'. All those big black spots are dust particles on the sensor.

Unless they are really big, they don't really show up until you've stopped the lens down a lot - because you are then getting light from a single point source and it doesn't scatter around the dust.

Anyone got good tips on sensor cleaning ? :)

Message edited by author 2003-04-12 12:43:38.

paganini

Canon EOS-1D Mark II

04/12/2003 02:35:05 PM · #16

Heheheheh, that's how you find DUST in your sensor.

You can never get rid of dusts... and it's hard to see it on the 70-200 mm lens for me, or even the 50 mm lens.... i think only at wide angle would it really affect the quality @ F16. F22 usually give me crappy photos, so i haven't used it much. Yes, the SKY test is the best to see dust. Set it on tripod and blast away.....

Though on the 10D it helps because the ANTIALIASING element is blocking the dust, and leaving the sensor a gap so that usually you don't see it unless it's really dirty.... (i.e. the plane of the sensor is not the same where the dusts are.

Haven't cleaned my sensor yet, afraid to..... check on Fred Miranda's website, there are a ton of info on the Canon forum. The only issue you'd have is if the dusts are BEHIND the anti-aliasing element, then the only way to get rid of it is to send it to Canon. They can do turnaround services if you are near them, but unfortunately the closet one is California for Texas....

Personally i don't understand why they don't employ a anti-static dust cover on the sensor so that it's hard to pick up dusts, then you can plug it in at home to try to get rid of them.... time for Canon to develop a SensorSquiggy system :)

I think we need a DPc challenge for DSLR's to show the worst dusts photo ever :)

Originally posted by Gordon:

Originally posted by paganini:
It's not always 1/3 from the scene, it depends on the aperature.

Lots of other good content - but on this 1/3rd in thing - I think I understand it better now. Optically the DoF is 1/3rd in front of the focal point and 2/3rds behind so, in general as a rule of thumb, if you focus one third into the 'depth' of the scene you'll get reasonably good DoF, with most of what you want in focus.

At the hyperfocal distance it's the same - acceptable focus starts half way between the camera and the focus point, and 2/3rds behind it, although that '2/3rds' goes to infinity hence it sort of breaks down a bit :)

The other nasty thing about using very small apertures is that is increases the amount of visible dust/noise in your images. For the brave at heart, try this. Stop your lens down to about f/22, take a shot of the sky or a white wall, and overexpose by about 1 and 1/2 stops. Load it up into photoshop and do an 'auto-levels'. All those big black spots are dust particles on the sensor.

Unless they are really big, they don't really show up until you've stopped the lens down a lot - because you are then getting light from a single point source and it doesn't scatter around the dust.

Anyone got good tips on sensor cleaning ? :)