Pencil in 8x10 on focus screen?

Alright, this may sound a little crazy, but I was wondering if making two small pencil marks on my 30d's focusing screen would cause any serious damage? I want to pencil in two small lines, or maybe just one that would indicate a 8x10 crop.

I've been shooting alot of events lately where everything printed are 8x10's and sometimes the crops are a little tight/loose, and it annoys me.

You probably could. Only damage would be to the screen itself and they're only 30 or 40 bucks. Check-out this site to purchase a pre-made screen. http://www.katzeyeopti​cs.com …rop-Lines--gridlines.html

Omg I love you! I am so buying one of those tomorrow, even though they're a wee bit on the pricey side...

Of course with a little practice you will figure it out in time and will not need to spend the money...

cbr929rrerion wrote in post #2309354
Of course with a little practice you will figure it out in time and will not need to spend the money...

I've had plenty of practice and can nail it most of the time. Thing is, I'm a perfectionist, and it seriously frustrates me when that 1 photo out of 20 comes out a little off.

To me the expense would be worth reducing my anxiety. Although I'll try the pencil route first.

I think i'd try to use a marker instead of a pencil, unless you meant pencil as a blanket term. I might infact try this.

What happens if you put the pencil mark in the wrong spot? Which will frustrate the perfectionist more? No pencil marks or pencil marks in the WRONG SPOT! hehee

I think a pencil or marker will leave a line that looks like it was made with a broom dipped in a bucket of paint when viewed through the viewfinder lens.

I'd use a ruler and a razor and just scribe very thin guide lines on the plastic.....

Jim_T wrote in post #2309461
I think a pencil or marker will leave a line that looks like it was made with a broom dipped in a bucket of paint when viewed through the viewfinder lens.

I'd use a ruler and a razor and just scribe very thin guide lines on the plastic.....

Good idea, the razor that is. I tried the pencil, it didn't affect metering, or hurt the screen at all. To draw the lines, I measured out the screen in mm's, and determined just how far in I needed to make the lines. It worked, but the lines were HUGE in the view finder. Like you said, looked like it was made with a broom vs. a pencil... I simply used an eraser to remove the pencil...

The razor sounds like a good idea though, but that'd be perminant damage... hmmm

What if a future camera had a feature that could overlay these grids electronically in the viewfinder, and be user selectable between different patterns, as well as being shut off? That would be a sweet feature. Isn't this already out there somewhere?

I think the 1d's have "crop" screens available to them.

Yes on those bodies, and the 5D and even 20D and 30D you can switch out the focusing screen. Here is a grid screen for the 5D as an example http://www.amazon.com …ion-Digital/dp/B000CSPOSI
What I mean is, electronically overlaying these different grids and crops on the fly and being able to quickly change the overlay in the menu or with a button.

rbush83 wrote in post #2310181
Isn't this already out there somewhere?

Yup. Nikon has it.

rbush83 wrote in post #2310181
What if a future camera had a feature that could overlay these grids electronically in the viewfinder, and be user selectable between different patterns, as well as being shut off? That would be a sweet feature. Isn't this already out there somewhere?

As René Damkot says It was a selectable (custom function) option on the Nikon F80 many years ago and I suspect it was on a few other models as well...

kevin_c wrote in post #2310394
As René Damkot says It was a selectable (custom function) option on the Nikon F80 many years ago and I suspect it was on a few other models as well...

Seriously? That's sick! Let's see them put it in Canon DSLR bodies...