Hard time focusing

A

AGreyCrane

New member
Very new to my DSLR and made my first pass reading through the sticky links.

Are many of you finding you have to adjust the focus manually? The auto focus just will not focus properly. I think I may be in the boat with other beginners to DSLR where my phone focuses perfectly, and my DLSR results look like crud!

My lenses are probably part of the issue, I'm currently trying to use my Canon EF-S 55-250mm F4-5.6 IS STM lens to get close up. The results are continually slightly out of focus when I do it manually, as I can't seem to dial it in fine enough.

Any suggestions?

Thanks!
 
I'm also in the beginning stages of learning mine. I have Been doing it manually because the auto focus is just a bit off usually. Esp when shooting fish. I also figured out that the editing makes a huge difference& you can adjust sharpness which helps.
 
When dealing with tank shots it is best to do manual focus. Also you should try your best to make sure you are squared up to the glass, basically no angled shots, just straight on.

This will help with any distortion that focusing would amplify the distortion.
 
You should also look at what the minimum focusing distance of the lens is. Having the lens as close to the glass as possible helps.
 
AGreyCrane said:
Very new to my DSLR and made my first pass reading through the sticky links.

Are many of you finding you have to adjust the focus manually? The auto focus just will not focus properly. I think I may be in the boat with other beginners to DSLR where my phone focuses perfectly, and my DLSR results look like crud!

My lenses are probably part of the issue, I'm currently trying to use my Canon EF-S 55-250mm F4-5.6 IS STM lens to get close up. The results are continually slightly out of focus when I do it manually, as I can't seem to dial it in fine enough.

Any suggestions?

Thanks!
Click to expand...

In addition to what was posted above about shooting straight through the glass and the minimum focusing distance, a couple other factors could be at play. If you have a really wide aperture (low F stop number) and are shooting hand held, your depth of field is going to be narrow and any small movements forward or backward when releasing the shutter will cause your image to be out of focus - solution, use a tri pod, and timed shutter release. Also, DSLRs from body to body, make to make focus differently. Check what focus setting you are using. For example, you could have single point, multi point, single point expansion, etc. Each mode is different and focuses your lenses differently - one setting will be better than another. Play around with it and you'll find the one that works best. Further, you may manually adjust your focus, get it just right, then press the shutter button - and automatically it tries to refocus! You can shut this off in your settings - that way, when you press the shutter button, it takes the picture only, and doesn't try and achieve focus. Turning AF off will do the same thing. Lastly, bodies and their ability to focus is based on light - if your meter is below -1 or -2 EV (your light meter in your display), depending on your body, your lenses may not achieve focus. A camera like the T3i or other entry level Canon will not be as good in this regard as a body like the 6D - which focuses to -3EV. Solution, adjust your settings to allow more light to hit the sensor, and then you should be able to achieve focus. HTH.
 
Some spot on replies right there! I cant overstate how important it is to be right at your glass and square to it. This will present a problem for focus distance for many lenses. Check out the specs on the lens and see what the minimum focus distance is. If its 12" or more youre not going to have anything in focus within that range. If its 18" or more, youre pretty out of luck for tank photography with that lens. Youll have to back away from the glass to shoot... not good.
Another factor is marine snow. Or whatever you want to call anything other than crystal clear water. Try photographing birds or wildlife in a snowstorm and youll see what I mean ;) Your lens starts chasing everything but the subject!
Finally, try shutting down all your pumps 5 minutes before you do a shoot. Things will settle out and movement within the tank will be at a minimum.
 
Thank you all for the responses.

I am using a tripod, and it looks like I will need to stick to my 18-55MM lens as it has a minimum focusing distance just under 9". My 55-200 has a minimum distance of 2'6".

I'll play around with the suggestions here and see how it goes. Thanks so much!
 
Here are some pictures I have taken since. Still having a hard time getting things to be focused just right. Especially getting the full shot in focus. Often just a portion is.







A portion of the original photo was in focus so I edited it down to make a background for my phone.
 
What is your fstop set to?

The fstop set the focus on a particular part of the picture.
A larger fstop will bring more of the image in focus.
 
Worm is correct about a higher fstop number bringing more in focus, but I think I would phrase it as:

Set the position of the focal plane on the subject using the focus ring on the lens. Then set how much of the subject is in focus in front and behind the focal plane with your aperture (size of lens opening). The resulting amount of area in focus is your depth of field. A wider lens opening (smaller f number) gives a more narrow depth of field, and a smaller aperture (higher f number) yields a wider depth of field.
 
Reef Bass said:
Worm is correct about a higher fstop number bringing more in focus, but I think I would phrase it as:

Set the position of the focal plane using the focus ring on the lens. Then set how much of the subject is in focus in front and behind the focal plane with your aperture (size of lens opening). The resulting amount of area in focus is your depth of field. A wider lens opening (smaller f number) gives a more narrow depth of field, and a smaller aperture (higher f number) yields a wider depth of field.
Click to expand...

Thank you for wording it like that. I was in a rush and headed to a meeting. I guess my mind ran faster than my fingers and I did not word that as descript as it could have been.
 
You are welcome. Thank you for not objecting to my restatement. You were correct with what you said.
 
As another completely clueless beginner with DSLR I discovered that I had my viewfinder adjustment set out of focus. I would focus things so they were near perfect in my mind and the camera was giving me nothing in focus. It seems that you need to set your viewfinder to be crisply focused on the lines in your viewfinder with the camera off and pointed at some homogenous background - that made a huge difference to me.
 
rsaha said:
As another completely clueless beginner with DSLR I discovered that I had my viewfinder adjustment set out of focus. I would focus things so they were near perfect in my mind and the camera was giving me nothing in focus. It seems that you need to set your viewfinder to be crisply focused on the lines in your viewfinder with the camera off and pointed at some homogenous background - that made a huge difference to me.
Click to expand...

I've been shooting for a few years now and just learned about that stupid little wheel. it was a duh and aha moment rolled all in one


also, a lot of lenses are soft when full extended. so you can try not quite fully extending to 250mm

due to the challenging lighting conditions, manual focus is best, and you can play with custom white balance settings.
 
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