Trouble Focusing

[Schatz]

Hi everyone,

I am having increasing difficulties producing sharp coin pictures. The main problem, of course, is my deteriorating vision, and despite all sorts of glasses, loupes, and other gadgets I seem to miss either the focus of the rims or the elevated centers of the coin, or both. Most likely my equipment is not at fault: I shoot with a lower end DSLR, a Vivitar Series 1  105mm macro,  a Sigma 50mm macro, and a Sigma 100mm macro with the camera mounted on a copy stand and the coin raised on a dowel stick, so that I am fairly close to the camera screen. But it seems to take me forever to focus manually - so long for each coin that my batteries have an annoyingly short life on LV. I have discarded the autofocus after some experiments, and the Vivitar lens has to be manually focused anyway. It is not a depth of field issue either (AV setting and f/11 or even f/16).

Now I heard that there are cameras one can attach directly to a laptop and use the computer screen for focusing. This would make the job much easier for me, I believe.  Do any of you have such a camera? If yes, which cameras are equipped with the necessary connections, and what does one have to look for when shopping for a DSLR? I do not want to spend a fortune on a new camera, so I would be interested in a relatively basic model from one of the major manufacturers (so that I can find adapters for my lens mounts).

Or is there another way of tackling this optical problem? I am really losing all joy of taking shots of my coins.

Frustrated,
Schatz

[Pekka K]

I use Ipevo P2V:

http://www.ipevo.com/prods/Point-2-View-USB-Camera

Pekka K

[Merinda]

I have a Camranger that allows you to control the camera from an iPad, including full screen focussing: Camranger.com. I am very pleased with it, though getting everything to talk to each other can be a bit fiddle at times

Allan

[Schatz]

Thanks, Pekka and Allan,

for your very useful suggestions and the links. I will explore both and try to find someone in my neighborhood who owns an Ipevo or a Camranger and can show me some work samples. There are a lot of teachers in our are, and I suspect they may use such equipment for their lessons.

Thanks again,
Schatz

[dougsmit]

I have no problem with using autofocus on my Canon Digital Rebel, 30D and 5DmkII BUT for coins it is best to have the autofocus set to consider just the central spot where the coin is rather than trying to focus on the whole image where there is nothing except in the center.  Are you set for central spot focus?   If you are manually focusing with bifocals or trifocals, use only the top part of the lenses for focus.  If you have progressive lenses, I really have no answer.  My eye doctor told me that they are often a problem for photographers and I should avoid them so I did.

I have no idea how you are having depth of field problems at f/11 unless you are shooting very tiny and very thick coins.  Perhaps posting some samples will show what might be causing the problem. 

[Schatz]

Doug,

thanks for your detailed reply and my apologies for reacting so late. I have solved my problem with the help of my Pentax discussion board and am embarrassed how simple the solution is. My excuse is that the user manual of my Pentax K-r makes no mention of a feature which comes in very handy for me:  the screen enlargements when you take Live Screen pics. All I need to do is hit the Info button when I am on LS and the image on the screen is enlarged by 2, 3, or 4 times, depending on how often I press the button. This gives you all the detail you need in macro photography if you do not use autofocus (which does not work in my case - I am using an old Vivitar Series One 105mm macro lens).

Thank you again for taking the time to respond to my cry for help. I am eternally grateful for your step-by-step picture illustrated instructions for image-stitching with PSE,

Schatz