Vision Through DSLR

[bmpress]

Hi Bob,

Now that some of us are aging and our eyesight is not quite as good as before, there are two questions:

1. Are we better off taking off our eyeglasses when focusing?
2. Are we better off using a 17-55 f2.8 rather than 17-85 f4.5/5.6?

I haven't seen any commentary about this issue and wonder how you feel about it.

Thanks,

[marcfs]

This is an interesting issue that I am faced with as well.  From my perspective there are three alternatives to focusing with aging eyes:  using glasses, wearing contacts and no glasses or contacts.

I always wear contact lenses when shooting.  My lenses are prescribed so that one lens is for distance and one lens is for reading. I use the distance lens for focusing, and the other lens helps me read the LCD screen.  The brain adjusts for mono-vision and quite honestly I don’t even realize that I'm wearing contact lenses.  BTW I use daily disposable lenses since I only use them one to two times per week.

I found that with my glasses on, which are progressive bi-focals, I   don’t have an accurate sense of when an image is tack sharp.  In auto-focus this is less of an issue.  However in manual focus for macro photography precision is critical.  Thus I use contact lenses and I am pleased with the results.

One other point to consider is the option of using live view.  I really like the added precision that can be achieved in live view.  Increasing the magnification of an image certainly aids manual focusing.  In fact I think live view has helped me take macro images to the next level.

Regards,

Marc

[bmpress]

Marc's comments were interesting. I also find that progressive eyeglasses make it very hard to focus since the smallest motion near the eye piece changes the focus of the eye. Now I am thinking that an alternative solution may be to change glasses to a single focus type which would allow seeing distances clearly as well as having a stable view through the camera.

But I also wonder if going to wider lenses might also help seeing the image.

[whizkid]

I doubt there is a better or best solution to your question. More a case of personal preference. I also wear progressives and find them acceptable using the viewfinder. Using glasses is helped with a camera that offers a viewfinder with good eye relief. At other times I take the specs off and spin the diopter adjuster to match my needs. The rub of diopter adjustment is quick iimage review as images are taken. No matter how I approach the issue there's a rub. I must say I never heard of using different contact lenses and the brain will adapt. Makes sense but I wonder if everyone can do that. My wife can't read in a car using glasses without her world spinning and she wasn't able to tolerate progressives either.
 

[KeithB]

marccfs:
I also wear contact lenses and have, ahem, reached that certain age.  My optometrist prescribed some bifocal contacts.  These do not work like traditional bifocal glasses.  The varying optical properties are concentric - both focal lengths are available to the eye at all times.  Your eye decides which focal point to use, and is therefore seemless.  It seems to work pretty well for me, though small text is often still too small.

[dwdong]

The viewfinder is designed for your best distance vision correction.  So the quick answer is that you are better off focusing with your eyeglasses on IF it is a distance prescription (not reading) that you are using.  However (always a however), if your correction is slight for distance, there is a small dial on many dslrs (often just up and right of the viewfinder window) that allows you to make a small distance correction so that you can use the viewfinder without your glasses.  Advantage here is that you can move your eye closer to the viewfinder. 

With regards to the lenses, it may be (I am not sure) that the f/2.8 will focus faster or more accurately in low light but should not matter much on a sunny day.

[marcfs]

Here's some info on monovision:

Monovision addresses the problem of presbyopia that most people start to encounter at the age of 40-45 when they begin to need reading glasses or bifocals for close vision.  With monovision, the dominant eye (the eye you would use to focus a camera) is focused for distance vision, and the non-dominant eye is focused for near to intermediate vision.  This can be done with contact lenses, refractive surgery or intraocular lenses.

additional info on monovision:  http://www.stlukeseye.com/eyeq/Monovision.asp

Marc

[whizkid]

There is still a question of viewfinder data that hasn't been discussed.  Holding your eyes away from the viewfinder makes seeing that data a problem. Again a reason for a viewfinder with high eye relief for eyeglass wearers. Then there is the data itself. IIRC, the data a viewfinder includes such as aperture, shutter speed etc, is set to appear as if the data is 1 meter away.

[KeithB]

My main problem with Monovision is that it keeps you from experiencing 3D movies!