Home News Buyers Guide About Advertising
 
 
 
   
Page 1 of 2 12 LastLast
Results 1 to 10 of 17
  1. #1
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,560

    Cool Aperture is worth a thousand bulbs

    This thread is a spin-off to answer 'Mish13's question concerning some possible procedural issues she could be having with her α350 and Zeiss lens.

    Quote Originally Posted by mish13 View Post
    Hi my name is Michelle and I live on the Gold Coast in sunny Queensland Australia.
    I am so glad I found this web sight, I have spent the last couple of weeks reading all the great information.
    I chose the Sony because a friend has an A350 and I liked his photos. but before I brought it the camera store told me I can take home up to three cameras for a week each before I decide. I tried a Canon and a Pentax, sorry I cant remember which models.
    I liked the feel of the Sony plus the flip screen is great for me because I have a bad back, so no bending down.
    I am a total novice and have lots to learn.
    My SonyA350 is my first DSLR and I am getting really frustrated.I have done two six week camera courses at the local tafe. I take lots of photos but still am not happy with the shots I take. I know its me and not the camera (I hope) I try to not put it in Auto but I end up with lots of bad photos. The colour is poor or the photo is blurry. I thought I would get great photos with the Carl Zeiss lenses but they are no better then the kit lenses
    One thing I don't understand is how do I know what aperture I can use for each lenses?
    As I said I am a total novice so excuse me if my questions are silly, thanks.
    If you are using the Zeiss lenses (I do not know which you have chosen}, some are capable of very wide apertures, but generally what you wind up fighting with lenses is DOF (depth of field) when you go for the brighter image via APERTURE.

    DOF is the characteristic result of mainly three elements:
    1. Aperture
    2. Distance to the center of focus (basically, what you have primarily focused on)
    3. Focal length of the lens


    There is a fourth (the sensor size), but since you are only working with one camera in this discussion ... that is a fixed variable and does not change.

    When you focus on a subject, say 10-feet away from you ... the "sharpest" point of focus you go for normally should be the eyes (animals, humans, what have you). From that point ... there exists a 'plane of focus' stretching up and down. That plane of focus extends out from the center of focus (the point you want the clearest and sharpest). The Depth of Field (DOF) around the center of focus varies with APERTURE. At a given focal length, it is shallow when the aperture is at its widest and becomes very deep when you tighten down the aperture.

    So, again, if you take an image of some one standing 10-feet away ... with a 16mm focal length ... at an aperture of f/3.5 ... the depth of field (DOF) is roughly 58.5-feet, 4.5 feet in front of the subject and 54 feet behind them will be in focus. It is kind of hard to miss the focus, shooting like that. Wide-Angle lenses normally have huge DOFs. It isn't until you get past 24mm where it becomes a "noticeable" change.

    Now ... zoom the lens to, say, 50mm, with the subject at the same distance from the camera ... the base aperture of your SONY Zeiss 16-80 f/3.5-4.5 automatically will contract f/3.5 due to the lengthening effect of the lens to about f/4.5 ... the result effect on the DOF from these two changes is that the DOF is now only 2.2 feet. As you can see, it is a lot tighter.

    Zoom the lens all the way out to 80mm @ f/4.5 ... and the DOF = 0.83-feet (10-inches). That is even tighter ... so anything around your subject is going to look out-of-focus (OOF) or lacking in "acceptable sharpness", unless it is very close or in line with the focal plane.

    A rough diagram may help you visualize what is happening (everything within the red lines should be in focus):

    Name:  DOF 16-80 labeled.JPG
Views: 1405
Size:  56.2 KB

    You should be able to visualize how at 80mm @ f/4.5 you could take a very nice portrait, as the background goes OOF. So as long as the person is more than a foot from the background, it "fuzzes out."

    Again, this is about APERTURE ... so stay zoomed out to 80mm and just change the aperture setting from f/4.5 -> f/8 -> f/16 The subject should still be at 10-feet from the camera for these distances to be correct.

    If you examine the images ... you will see as the aperture tightens up, the DOF grows and items around your subject become more focused and clearly defined.

    Name:  DOF 16-80 aperture changes.JPG
Views: 4164
Size:  51.6 KB

    Of course, there is a loss of serious light, closing down the aperture ... so you will have to compensate by either increasing the ISO or slowing down the Shutter Speed.

    Calculating DOF can be easily done by going to the link ... putting in your variables and there it is!

    BTW: If ANY of these terms or acronyms seem vague, please go to the "second sticky" thread, in this forum, and review the list.
    Last edited by DonSchap; 05-12-2009 at 10:34 AM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

  2. #2
    Join Date
    Oct 2008
    Location
    Raleigh, NC, USA
    Posts
    788
    I looked at her post in the other thread and the CZ lens she is referring to is the 16-80. Great lens, but not a super wide aperture. As Rooz said, the book "Understanding Exposure" is probably the best place for a new photographer to start.

    Because the CZ 16-80 only has a moderately wide aperture, DOF probably isn't your problem. Don was thinking you might have one of the primes or one of the f/2.8 zooms.

    More than likely your problem is with two of the toughest things in photography, white balance (hurting the color) and shutter speed (creating blurry images).

    Basically when you were shooting with a point and shoot on auto it would use the flash or bump up the ISO when light was low, so it always used a short shutter speed. A DSLR allows you to use a slow shutter speed, which is very nice in some conditions, but if you are hand holding or taking pictures of people or animals, your pictures will be blurry with a long shutter speed.

    White balance can be a challenge, but luckily is a much easier fix. I don't know why SLRs seem to have a harder time with white balance than point and shoot cameras. I used to have an A300, which is almost identical to the A350, just 10MP instead of 14MP. I didn't have a lot of trouble with the auto white balance. But I shot in RAW (it is under image quality) and I could bring pictures into the computer and change the white balance. That is one of the big benefits about shooting RAW, you can change most of the image settings later. My current camera, the Canon 40D, struggles with auto white balance in doors, but I just keep shooting and fix it in Adobe Lightroom.

    Aperture is a diaphram inside the lens that controls how much light gets in. The trade off is that a larger aperture has a shallower depth of field as Don is explaining above. The smaller numbers represent a larger aperture, because the aperture is basically the bottom part of a fraction.

    When people say a lens is "fast" they mean it has a large aperture, which is a smaller number. Except for Olympus, as far as I know the fastest zoom lenses on the market are f/2.8. Primes (non-zoom) as you know from your Minolta 50mm can get much faster, commonly down to f/1.4, but some as fast as f/0.95.

    The CZ lens you have is not as fast as their pro lenses, and doesn't quite have the build quality, but it is incredibly sharp, and well respected. Some people say it should have better build quality to be called Carl Zeiss, but for the price you pay, it is a great lens. Sell the 18-70, or use it as a paper weight. It will do more good for your images if you use it to throw at subjects to get them to move. Especially with such a great Carl Zeiss lens in your bag.
    Jason Hamilton
    Selective Frame

    EOS 5D - Canon EF 24-85mm f/3.5-4.5 USM, EF 35 f/2, EF 50mm f/1.8 Mk II, EF 70-210 f/3.5-4.5 USM, EF 85mm f/1.8 USM, EF 100mm f/2.8 Macro, Helios 44-2 58mm f/2 (with EOS adapter), 430EX, Canon S90
    Nikon FE - Nikkor 35mm f/2 AI'd, Nikkor 50mm f/1.8 AI, Nikkor 105mm f/2.5 AI, F to EF adapter, 2xVivitar 285, other lighting stuff
    Mamiya C220 - 80mm f/2.8

    Gear List flickr

  3. #3
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,560
    Thanks, Jason ... good points. The reading material is perhaps the best and most consistent reference to all of this.

    'Mish13'
    ... if you could post a couple of your "problematic shots" and their associated camera setting (EXIF Data), we may be able to provide a deeper level of understanding for the problem you are experiencing. We'll cut right to the chase and see what we shall see.
    Last edited by DonSchap; 05-11-2009 at 07:55 PM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

  4. #4
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,560

    Cool Aperture Values

    Another aspect of APERTURE is that it directly controls the amount of light that gets through the lens to the camera media.

    Here is a relationship Chart that kind of explains it:

    Aperture settings
    How they relate to source lighting, whatever that source is (e.g., sunlight, lamp light, candle, LED)

    Consider source light has a value of "1"

    Therefore, an aperture setting of:

    f/0 = source lighting (please let me know if you find a lens that can deliver this level of brightness)
    f/1 = source lighting
    f/1.4 = source lighting
    f/2 = 1/8th source lighting
    f/2.8 = 1/16th source lighting
    f/4 = 1/32th source lighting
    f/8 = 1/64th source lighting
    f/11 = 1/128th source lighting
    f/16= 1/250th source lighting
    f/22 = 1/500th source lighting
    f/32 = 1/1000th source lighting

    So, if you are using the sun as your source and your aperture is set to f/8, your camera can only see 1/64th of the available sun light. Then through sensor sensitivity (ISO) or Shutter Speed, you can cause an apparent brightening of it to the sensor.

    I hope this was somewhat helpful.
    Last edited by DonSchap; 05-12-2009 at 06:59 PM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

  5. #5
    Join Date
    Mar 2009
    Location
    San Diego, CA
    Posts
    602
    I just want to say that this is a fantastic discussion! I for one am learning a lot and those are some great resources.

    I hope it keeps on going.
    Darin Wessel
    α 900
    Zooms: Tamron SP AF70-200mm f2.8 Di LD Macro; Sigma 28-90mm D macro, Konica-Minolta 18-70 f3.5-5.6
    Primes: Minolta 28mm f2.8; Sony 50mm f1.4
    Minolta RC-1000 remote commander

    Film:
    Calumet Cambo CC400 4x5 View Camera
    YashikaMat 6x6 TLR (other accessories)
    Minolta Maxxum 7000 w/ Minolta 35-80mm f/4-5.6 & Minolta 2800 flash
    Minolta Maxxum 5000i & Vivitar 728 AFM flash
    What's next???

  6. #6
    Join Date
    Apr 2009
    Location
    Qld Australia
    Posts
    11
    Boy did I stumble on a great web sight, I am blown away by your help and just want to say how much I appreciate it.
    I guess I thought if I spent $1200 on a Zeiss lens it would fix all my problems, how naive.
    I have just ordered this Tamron lens, it will be my last purchase until I take better photos
    1 x SP AF11-18mm F/4.5-5.6 Di-II LD Aspherical (IF) **SONY ONLY** (SP AF11-18mm F/4.5-5.6 Di)
    Mount Sony + $0.00
    Don I will read and re-read your post and look at the diagrams until it sinks in.
    Here are a few photos (I hope not to many, and they are not to small) I took the other morning at 5am, we drove down by the water to try and catch the sunrise. Unfortunately it was a cloudy morning so the sun didn't appear. In my view finder these shots looked OK, its when I see them on the computer they look dark or yellow looking.
    They were all taken in Aperture priority and no flash was used, I also only used the zeiss lens that is F3.4-4.5 ZA
    Aperture F4.0, Lens focal length 18.0mm,Shutter speed 1/3sec,Iso 400, White balance Day light

    This photo came out orange looking?
    Lens focal length 20.0mm,Shutter speed 1/4sec, F4.0,Iso 400, White balance day light

    This photo lacks color
    Lens focal length 40.mm,Shutter speed 1/30, F4.5, Iso 400, White balance Cloudy

    This light house picture was taken about 6am in the morning so it was day light but it came out dark.
    Lens focal length 24.mm,shutter speed 1/250sec, f4.5, Iso 400, White balance Auto,

    Lens focal length 18.0mm, Shutter speed 1/100, F4.5, Iso 400, White balance Auto

    I was trying to show depth of field, what could I have done to improve this photo?
    A4.5,(I thought I had it on F22) lens focal length 60.0mm, shutter speed 1/100sec, Iso 400,

    This was taken around 7am but the boats came out dark?
    F4.0, lens focal length 30.0mm, Shutter speed 1/4000. Iso 400

    Again I was trying to show depth of field
    F22, lens focal length 16.0mm, shutter speed 1/25, Iso 400, White balance auto


    Sony A700
    Minolta: 50mm
    Sony: DT 16-80mm F3.5-4.5 ZA Zeiss lenses
    Sony: 75-300mm F4.5-5.6 kit lenses
    Sony: 18-70 F3.5-5.6 kit lenses
    Tamron: SP AF 90mm F2.8 Macro

  7. #7
    Join Date
    Jun 2008
    Posts
    2,204
    A bit small, but from what I see overall very nice. The first could use a slightly longer exposure but it's my favorite of the bunch, thanks for sharing!
    flickr

    Canon 7D - 5D | 550EX - 430EX II - (2) PW FlexTT5 | 24-105 f4L | 70-200 f2.8L IS | 100 f2.8L IS | 50 f1.8 II

  8. #8
    Join Date
    Feb 2006
    Location
    Des Plaines, IL
    Posts
    9,560

    Smile simple critique for adjustment

    Quote Originally Posted by mish13 View Post

    Boy did I stumble on a great web sight, I am blown away by your help and just want to say how much I appreciate it.
    I guess I thought if I spent $1200 on a Zeiss lens it would fix all my problems, how naive.
    I have just ordered this Tamron lens, it will be my last purchase until I take better photos
    1 x SP AF11-18mm F/4.5-5.6 Di-II LD Aspherical (IF) **SONY ONLY** (SP AF11-18mm F/4.5-5.6 Di)
    Mount Sony + $0.00
    Don I will read and re-read your post and look at the diagrams until it sinks in.
    Here are a few photos (I hope not to many, and they are not to small) I took the other morning at 5am, we drove down by the water to try and catch the sunrise. Unfortunately it was a cloudy morning so the sun didn't appear. In my view finder these shots looked OK, its when I see them on the computer they look dark or yellow looking.
    They were all taken in Aperture priority and no flash was used, I also only used the zeiss lens that is F3.5-4.5 ZA
    Okay ... one of the important aspects of photography is having a clear subject, otherwise it looks like you are taking an image for the sake of the image. If you can create a composition that portrays "a story" or "a message" of some kind ... it makes the image interesting and people begin to look closer. If your image is mundane, unclear, common or lackluster, it hardly gets more than a blink. That being said ... solutions to your images for pulling up "detail" and adjustments for lighting follow. Remember, nothing is in concrete and these are just some thoughts to consider in future shots or redos.

    Quote Originally Posted by mish13 View Post


    Aperture F4.0, Lens focal length 18.0mm,Shutter speed 1/3sec,Iso 400, White balance Day light
    This image begs the question, what was the subject? As you say, the sunrise is lost behind the clouds, so that is out. The distant figure is fuzzy and non-distinct ... but, you have wonderful lines to work with ... they just need to point to something. You need that subject to save a shot like this ... and it is missing.

    Quote Originally Posted by mish13 View Post


    This photo came out orange looking?
    Lens focal length 20.0mm,Shutter speed 1/4sec, F4.0,Iso 400, White balance day light
    Time of Day for an image is important, as this shot points out. The sun has a red/yellow cast to it as it comes through the horizon. So, knowing this, you would need to select a White Balance (WB) temperature (measured in degrees Kelvin or K) that would adjust for this. In this case, to eliminate the yellow for a more natural look to the color, you would probably use 2800 to 3200K (alternate would be the "Tungsten" setting) as the selected temperature for the "WB" You can go as low as 2500K on most of the DSLRs.

    When the sun is up around 8:30AM ... that golden glow fades away and the light temperature climbs quickly ... to 5600K or the "daylight" setting.

    The focus looks like it was "Spot" and directed at the sky for an infinity focus. To tighten this up, you need to turn the camera and get a focus on, in this case, the sign under "KIOSK", half press the shutter to "lock" the focus ... then return the camera position to facing down the walkway, like the current image is ... and complete the shot by fully depressing the shutter release.

    Quote Originally Posted by mish13 View Post


    This photo lacks color
    Lens focal length 40.mm,Shutter speed 1/30, F4.5, Iso 400, White balance Cloudy
    Unfortunately at this time of day, color is at a premium. The sun needs to be higher and more direct, as you can see that the sky is rather blase' and offered no direct lighting or reflectivity. It is the sky that usually gives the water its blue color. Adjusting the saturation could possibly augment the color ... and there are other filtering methods that might be employed. Still, you would probably be better served by waiting an hour or two and retaking this shot.

    Light is what gives your color ... brilliance.

    Quote Originally Posted by mish13 View Post


    This light house picture was taken about 6am in the morning so it was day light but it came out dark.
    Lens focal length 24.mm,shutter speed 1/250sec, f4.5, Iso 400, White balance Auto,
    What you have in this image is the "silhouette-effect" (Brighter background than the subject). One solution for this is, if you want the detail of the lighthouse to show-up is "fill-flash" or a very large reflector, positioned to shove the incoming light in another direction ... namely to the lighthouse.

    Another approach is to try and take three exposures and do an HDR of the image. The HDR will allow you to render the shadows and the highlights better and literally pull the lighthouse out of the dark. This is done with post processing (Photoshop CS3 or 4, LightRoom 2 or some other post processing software package)

    We all have fun with this kind of shot ...

    Here might be an HDR rendition of it:
    Name:  Lone-lighthouse_HDR2.jpg
Views: 1164
Size:  58.9 KB

    Quote Originally Posted by mish13 View Post


    Lens focal length 18.0mm, Shutter speed 1/100, F4.5, Iso 400, White balance Auto
    Again, this is more B&W ... lacking color from a low sun. Just gotta wait it out.

    Quote Originally Posted by mish13 View Post


    I was trying to show depth of field, what could I have done to improve this photo?
    A4.5,(I thought I had it on F22) lens focal length 60.0mm, shutter speed 1/100sec, Iso 400,
    This is one of those shots where you need to just poke your camera beyond the horizontal railings and the first pier supports are rather unimportant too. They are doing nothing for the shot, in my opinion. Rotate the camera into the "portrait" or vertical position, reframe it and make sure to get the yellow sign as an "interest point" and retake it.

    Quote Originally Posted by mish13 View Post


    This was taken around 7am but the boats came out dark?
    F4.0, lens focal length 30.0mm, Shutter speed 1/4000. Iso 400
    This one is a monster, due to the size of the image. Again, could be easily solved with an HDR rendition (3-shots) or, possibly, employing the use of a half-ND4 grad filter. That would allow for a longer exposure, to pull up the boats ... and still get the sun at the proper brilliance.

    Quote Originally Posted by mish13 View Post


    Again I was trying to show depth of field
    F22, lens focal length 16.0mm, shutter speed 1/25, Iso 400, White balance auto
    The last shot, to me, is pointless. You have a piece of a building in the background ... a stretch of pier-bridge .. you know what I mean
    ? If you had, at least, an animal or a human in the shot, but its just a road. Heck, even if part of it had fallen away ... it would be a subject -> damage. I suppose you could walk under the cridge to the other side and get the entire building, with its reflection going, next to the bridge. The composition would probably improve.

    Anyway ... I don't know how much help I was ... I suspect others have their views.
    Last edited by DonSchap; 05-12-2009 at 11:55 PM.
    Don Schap - BFA, Digital Photography
    A Photographer Is Forever
    Look, I did not create the optical laws of the Universe ... I simply learned to deal with them.
    Remember: It is usually the GLASS, not the camera (except for moving to Full Frame), that gives you the most improvement in your photography.

    flickr & Sdi

  9. #9
    Join Date
    Apr 2009
    Location
    Qld Australia
    Posts
    11
    Thanks Don you have been a huge help, you hit the nail on the head when you said have a clear subject. I do tend to just snap away and hope that I might get one good shot out of 200.
    I will take eveything you said on board and try and get my head around it. I have so much to learn about lighting and what settings to use for each occassion.
    I am off to practice, practice, practice.
    Thanks Michelle
    Sony A700
    Minolta: 50mm
    Sony: DT 16-80mm F3.5-4.5 ZA Zeiss lenses
    Sony: 75-300mm F4.5-5.6 kit lenses
    Sony: 18-70 F3.5-5.6 kit lenses
    Tamron: SP AF 90mm F2.8 Macro

  10. #10
    Join Date
    Dec 2007
    Posts
    2,562
    Good job Don. You need to check the histogram it will help you get the proper exposure. Here is a link that might help. http://www.llvj.com/tutorials/unders...stograms.shtml Just keep shooting you will get it. What program are you using to edit your images?

    Frank
    Sony A77
    Sony A580
    Sony A 100
    Maxxum 400si.
    Sony 18-70 Kit Lens
    Minolta AF 35-70
    Minolta AF 50 f/1.7
    Tamron 70-300 f/4-5.6 Di LD
    Tamron 60mm Macro
    Tamron 17-50 f/2.8
    Tamron 2x Converter
    Sony HVL-F42AM
    Quantaray 70-300 4.5-5.6 Macro
    Slingshot 200 Bag



    http://www.flickr.com/photos/22083244@N06/

    http://s305.photobucket.com/albums/nn219/sparkie1263/

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •