Jamdiver
Guest
Best of luck with you String.
Looking forward to the pics
.
Looking forward to the pics
.
Canon A620...shadows.
- Thread starter O'Malley
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OP
O'Malley
Contributor
Experienced the same effect topside but using the diffuser plate has corrected the problem...no more shading. Thanks, everyone, for your feedback. A couple more sessions in the pool and hopefully I'll have some nice shots to share upon returning from Curacao.
O'Malley:
Since you'll be diving with sunset divers you'll get a nice chance to practice on some seahorses in pretty shalow water. I found a nice one 2 weekends ago and notified Kurt, one of the instructors there. He should be able to show you where it is. I would suggest having a practice shoot walking in from the shore before you head out for Watamula etc.
Maybe i'll bump in to you there so we can share our experiences with this camera
Managed to go diving finally and get some photos. Air temperature about -2c (28f), ice on the boat etc but generally ok.
Underwater visibility around 3m which meant mainly macro shots and anything more than 50cm away caused loads of back scatter with flash. For all the photos with flash i used the diffuser plate and saw no shadows.
Few below:
Lobster
Starfish
Finally, this is what you get when you give a buddy who hasnt used a camera much the thing and ask him to take your photo. I cant believe he spent ages trying to frame this shot as well !
Im in there somewhere, can just make out wing and mask. Thats the last time i ask him...
Im fairly happy with the photos however have noticed on some photos that the edges are slightly blurred. I think but not sure this is when the zoom is full out, it MAY be the edge of the lense causing it. Anyone else noticed this?
2 photos linked below (unshrunk to highlight the effect). Both of these all around the edge is a bit blurred.
http://www.whitcombe.org.uk/files/blur_edge1.jpg
http://www.whitcombe.org.uk/files/blur_edge2.jpg
Underwater visibility around 3m which meant mainly macro shots and anything more than 50cm away caused loads of back scatter with flash. For all the photos with flash i used the diffuser plate and saw no shadows.
Few below:
Lobster
Starfish
Finally, this is what you get when you give a buddy who hasnt used a camera much the thing and ask him to take your photo. I cant believe he spent ages trying to frame this shot as well !
Im in there somewhere, can just make out wing and mask. Thats the last time i ask him...
Im fairly happy with the photos however have noticed on some photos that the edges are slightly blurred. I think but not sure this is when the zoom is full out, it MAY be the edge of the lense causing it. Anyone else noticed this?
2 photos linked below (unshrunk to highlight the effect). Both of these all around the edge is a bit blurred.
http://www.whitcombe.org.uk/files/blur_edge1.jpg
http://www.whitcombe.org.uk/files/blur_edge2.jpg
RonFrank
Contributor
O'Malley,
I think you have figured this out, but it appears that you are getting shadows because you are not lighting the area that the lens is covering. With a 35mm EQ lens you would need 62 degrees of coverage, and your strobe (DS125) provides 90 degrees. I'd suggest that you are not aiming your strobe properly.
String,
Your blurry edges are a result of not enough DOF (Depth of Field). Camera's focus on ONE plane, and one only. So in reality there is only ONE focal plane that is sharp in ANY image. So why can an entire image appear sharp from corner to corner? That is a result of what is called Depth of Field.
The two major factors that control depth of field are the aperture, and the focal length of a lens. Wide angle lenses have a much greater DOF vs. longer focal length lenses. Aperture is used to increase DOF. The wider the aperture (f2.8 is wide) the less DOF.
It is not always possible to include everything as sharp in an image, even if one uses the widest lens setting, and the smallest aperture setting.
These are very basic photo 101 concepts. I would highly recommend learning a bit more about photography. There is a lot of good sites where you can learn more about the basics of photography and exposure control.
I think you have figured this out, but it appears that you are getting shadows because you are not lighting the area that the lens is covering. With a 35mm EQ lens you would need 62 degrees of coverage, and your strobe (DS125) provides 90 degrees. I'd suggest that you are not aiming your strobe properly.
String,
Your blurry edges are a result of not enough DOF (Depth of Field). Camera's focus on ONE plane, and one only. So in reality there is only ONE focal plane that is sharp in ANY image. So why can an entire image appear sharp from corner to corner? That is a result of what is called Depth of Field.
The two major factors that control depth of field are the aperture, and the focal length of a lens. Wide angle lenses have a much greater DOF vs. longer focal length lenses. Aperture is used to increase DOF. The wider the aperture (f2.8 is wide) the less DOF.
It is not always possible to include everything as sharp in an image, even if one uses the widest lens setting, and the smallest aperture setting.
These are very basic photo 101 concepts. I would highly recommend learning a bit more about photography. There is a lot of good sites where you can learn more about the basics of photography and exposure control.
Im not convinced its that straight forward as im not getting the edge blurs on the camera without the underwater housing and didnt get them on my previous canon UW camera/housing combination.
String,
Soft edges at full telephoto is not that uncommon, especially when external wet mate lenses are added ( I know this is not the case in this particular instance). If you have access to EXIF info, that would be helpful in critiquing the images posted. EXIF will include among other info, aperture, shutter, ISO, focal length, etc..........
One option to avoid soft edges is to pull back slightly from full zoom. Actually I was taught that when possible it is always better to zoom with your fins than with your lens.............
If you are having difficulty in stopping action, especially on land, while maintaining a desired amount of DOF (smaller aperture), one option is to increase ISO. This will allow for the possibility of both faster shutter speeds and smaller apertures, but at the expense of an increase in "grain" or "noise". But otherwise, an acceptable exposure may be within reach..........
f/4.1 is the widest aperture available for your camera's lens when telephoto focal lengths are chosen. For wide angle, apertures as wide as f/2.8 are attainable.
Old rule of thumb, shutter speed should equal focal length (relative to 35mm focal length) IOW, if your equivalent focal length at zoom is 140 mm, then your shutter speed should be about the same (1/140 sec)to avoid motion blur when hand held. This is only a guide, not written in stone.
hth,
b
Soft edges at full telephoto is not that uncommon, especially when external wet mate lenses are added ( I know this is not the case in this particular instance). If you have access to EXIF info, that would be helpful in critiquing the images posted. EXIF will include among other info, aperture, shutter, ISO, focal length, etc..........
One option to avoid soft edges is to pull back slightly from full zoom. Actually I was taught that when possible it is always better to zoom with your fins than with your lens.............
If you are having difficulty in stopping action, especially on land, while maintaining a desired amount of DOF (smaller aperture), one option is to increase ISO. This will allow for the possibility of both faster shutter speeds and smaller apertures, but at the expense of an increase in "grain" or "noise". But otherwise, an acceptable exposure may be within reach..........
f/4.1 is the widest aperture available for your camera's lens when telephoto focal lengths are chosen. For wide angle, apertures as wide as f/2.8 are attainable.
Old rule of thumb, shutter speed should equal focal length (relative to 35mm focal length) IOW, if your equivalent focal length at zoom is 140 mm, then your shutter speed should be about the same (1/140 sec)to avoid motion blur when hand held. This is only a guide, not written in stone.
hth,
b
Seems ive got a lot of playing about to do still. The blurred edges arent all full telephoto though zoomed in they appeared to vanish which is why i think it maybe an artifact of the physical edge of the lense in the housing.
As for exif:
Lobster: Shutter 1/60 F2.8 focal length 7mm. No ISO data in exif
Starfish: Shutter 1/60 F3.2 focal length 8mm. No ISO data in EXIF
Blue edge1: Shutter 1/60 F3.2 focal length 7mm. No ISO data in EXIF
I'll try above water action shots again Jan 2nd. Hopefully lighting conditions will be a bit better. Done more playing/reading the last few days and getting better results so its not all doom and gloom, things are improving just done differently from my older cameras.
As for exif:
Lobster: Shutter 1/60 F2.8 focal length 7mm. No ISO data in exif
Starfish: Shutter 1/60 F3.2 focal length 8mm. No ISO data in EXIF
Blue edge1: Shutter 1/60 F3.2 focal length 7mm. No ISO data in EXIF
I'll try above water action shots again Jan 2nd. Hopefully lighting conditions will be a bit better. Done more playing/reading the last few days and getting better results so its not all doom and gloom, things are improving just done differently from my older cameras.
Jamdiver
Guest
String,
No ISO data in EXIF happened most likely because ISO was left in auto mode.
I've found that the ISO settings of 200 or 100 work better in low light situations but can introduce 'noise' into the images.
Nice photos, I especially like the lobster.
What settings i.e mode did you take those photos in? 'TV', 'AV'?
By the way i'd suggest starting with nudibranchs or some other small subjects in macro mode, you're likely to get more pictures worth keeping that way.
I've found that in macro mode the A610/A620 will focus down to about 5 cm, it focuses very well..
Glad that you're making some improvements with the camera.
No ISO data in EXIF happened most likely because ISO was left in auto mode.
I've found that the ISO settings of 200 or 100 work better in low light situations but can introduce 'noise' into the images.
Nice photos, I especially like the lobster.
What settings i.e mode did you take those photos in? 'TV', 'AV'?
By the way i'd suggest starting with nudibranchs or some other small subjects in macro mode, you're likely to get more pictures worth keeping that way.
I've found that in macro mode the A610/A620 will focus down to about 5 cm, it focuses very well..
Glad that you're making some improvements with the camera
.
RonFrank
Contributor
String:
I am. If you had vingetting, then your corners would be dark, maybe even black. Sometimes it can result in white corners, but generally not.
You have detail at the corners, and very little light falloff. Also look at the images. The corners that are blurry (or out of focus) are the closest thing to the camera.
This is a case of shallow DOF, and maybe a bit of camera shake. It's rather unmistakable, and the fact that one corner is soft in one image, and then another corners is soft in a different image indicates that nothing is blocking the lens.
As the problem does not persist when using the camera topside, this is simply a case of poor technique, and you can hardly expect edge to edge sharpness when shooting at F2.8, or f3.5 which is exactly what you were doing.
