Another newbie question.

[matrosov]

I apologize in advance for series of dumb questions that I will be asking as I am trying to unwind myself from auto mode and take control of my camera. I was trying to shoot a time interval photos for my son's crystal growing experiment for school to stitch them into a time lapse vid. Below is one of the images. Nikon D5100, shot full manual at f2.8 1/10 shutter 50 mm zoom 100 ISO, no flash because I couldn't figure out how to dial it in properly it was giving me all kind of problems bouncing off this glass jar. Just looked too bright on LCD screen The exposure indicator on the camera was about 0, the focus light was on, looked pretty sharp in viewfinder too. The big picture was not as clear as I was hoping it would be. So question is where did I mess up? I tried different apertures and shutter speeds afterwards did not get significantly better results.

 

[astroNikon]

That specific image is
Lens: 17-50 mm f/2.8
Shot at 50 mm (shot wide open)
Exposure: Manual exposure, 1/10 sec, f/2.8, ISO 125

A couple questions/comments come to mind
1 - how close were you to the glass?
If you are too close you camera ill not be able to focus on it. In checking he 17-50/2.8 it does work up to 11 inches away for focusing. If you are closer then you will never get focus. The pencil on top may or may not be withing focus distance depending upon distance and Aperture (depth of field).

2 - Looking at the pencil on top, it looks like it's not just a focus blur but also potential movement. Shutter speed eliminates movement of the camera/person. A 1/10 shutter speed requires no movement on the shooter (which takes a lot of practice). I would recommend at least a 1/125 shutter speed. Anything less than that and you can induce blur just from pushing the release button and shaking the camera ever so slightly.

3 - if you are using AutoFocus it will probably try to focus on the jar itself, rather than the object inside. If you want to focus on the dangling object you'll probably have to manually focus on it.

(edit) 4 - I forgot to mention your f/2.8 Aperture in more detail. If you were say 12 inches from the subject, at f/2.8 and a 1.5x crop camera your depth of field would have been 0.16 inches. And if the camera focused on the glass that means that the object would probably have been out of focus from a lack of depth of field. In this case, focusing on the subject itself, and with the addition of using a smaller aperture such as f/5.6 would provide more focus depth.

BUT be aware that shooting through thick, non optical glass like a glass jar PLUS liquid is going to reduce details in the image itself no matter what you do short of taking the thing out of the glass jar and liquid it is in.

To test these things out you would have to start with a tripod and remote release and a 3 second shutter delay, as this will generally eliminate camera shake at slower shutter speeds.

but I would just try a fast shutter speed 1/125, which will require a higher ISO
Then use manual focus.

I believe the d5100 is good to about ISO 1600 before ISO noise creeps in too much.

If you have to add flash to obtain a faster shutter speed then put a white business card in front of your popupflash and try to bounce the light up to the ceiling to bounce back down. A direct flash on glass will glare badly.

 

[matrosov]

That specific image is
Lens: 17-50 mm f/2.8
Shot at 50 mm (shot wide open)
Exposure: Manual exposure, 1/10 sec, f/2.8, ISO 125

A couple questions/comments come to mind
1 - how close were you to the glass?
If you are too close you camera ill not be able to focus on it. In checking he 17-50/2.8 it does work up to 11 inches away for focusing. If you are closer then you will never get focus. The pencil on top may or may not be withing focus distance depending upon distance and Aperture (depth of field).

2 - Looking at the pencil on top, it looks like it's not just a focus blur but also potential movement. Shutter speed eliminates movement of the camera/person. A 1/10 shutter speed requires no movement on the shooter (which takes a lot of practice). I would recommend at least a 1/125 shutter speed. Anything less than that and you can induce blur just from pushing the release button and shaking the camera ever so slightly.

3 - if you are using AutoFocus it will probably try to focus on the jar itself, rather than the object inside. If you want to focus on the dangling object you'll probably have to manually focus on it.

To test these things out you would have to start with a tripod and remote release and a 3 second shutter delay, as this will generally eliminate camera shake at slower shutter speeds.

but I would just try a fast shutter speed 1/125, which will require a higher ISO
Then use manual focus.

I believe the d5100 is good to about ISO 1600 before ISO noise creeps in too much.

If you have to add flash to obtain a faster shutter speed then put a white business card in front of your popupflash and try to bounce the light up to the ceiling to bounce back down. A direct flash on glass will glare badly.

Thanks Astro. Camera was about 20-24 inches away on a tripod angled down at maybe 20 degree towards the jar. It was set up on time interval every 20 seconds for 5 hours. This image was from the middle of the pack. Since I was on tripod I figured no harm at keeping ISO low and aperture wide open and let shutter be as slow as it needed to be. I checked tripod and there is no up and down motion to the head I can turn it by hand left and right but it it's not free turning requires deliberate force. So I am guessing the problem is more closely related to your point about AF, it might have started fishing around the glass taking each successive shot. I have SB900 and I tried couple from tripod with popout white card deployed angled whichever different direction and different settings for light angle switch and it did not look very natural to me on LCD so given limited amount of time on hand I figured that evenly darker would be better than unevenly brighter.

 

[astroNikon]

Thanks Astro. Camera was about 20-24 inches away on a tripod angled down at maybe 20 degree towards the jar. It was set up on time interval every 20 seconds for 5 hours. This image was from the middle of the pack. Since I was on tripod I figured no harm at keeping ISO low and aperture wide open and let shutter be as slow as it needed to be. I checked tripod and there is no up and down motion to the head I can turn it by hand left and right but it it's not free turning requires deliberate force. So I am guessing the problem is more closely related to your point about AF, it might have started fishing around the glass taking each successive shot. I have SB900 and I tried couple from tripod with popout white card deployed angled whichever different direction and different settings for light angle switch and it did not look very natural to me on LCD so given limited amount of time on hand I figured that evenly darker would be better than unevenly brighter.

With your description I would guess the AF too
Try manual focus
also keep in mind you are shooting through non-optical glass and a liquid.

try a few tests in manual focus. The rest of the setup sounds okay.

 

[Derrel]

You screwed up by using f/2.8 at close distance. F/2.8 ruins more photos than it helps.

A smaller aperture, like f/11, with a slow-speed exposure, would have been a better choice.

At this close distance, deeper depth of field would have helped a fair bit: I would likely myself have even stopped down to f/16. Manually-focused, of course, and the focusing ring maybe even taped down with a bit of painter's tape. Also, this looks a wee bit under-exposed.

 

[matrosov]

You screwed up by using f/2.8 at close distance. F/2.8 ruins more photos than it helps.

A smaller aperture, like f/11, with a slow-speed exposure, would have been a better choice.

At this close distance, deeper depth of field would have helped a fair bit: I would likely myself have even stopped down to f/16. Manually-focused, of course, and the focusing ring maybe even taped down with a bit of painter's tape. Also, this looks a wee bit under-exposed.

Ahah. Time for take three . I'm beginning to question the setup in a jar. As this thing starts growing it begins playing games with a light inside and outside the jar. Time for something wide and shallower so I can maybe shoot it from above. I noticed it's a little too dark even though exposure indicator is dead at zero, but I figured I can recover most of it in lightroom since I need to crop it in tight anyway. Thanks a lot for all your feedbacks. Wife is about to blow the gasket with it makes it double the fun.
And as I popped the first batch into the computer I noticed that WB was way off , so much for auto WB on the camera. With WB corrected in lightroom the clarity of that water improved quite a bit.