Back Focus Chart
Find great deals on eBay for back focus chart. Shop with confidence. Back-Focus Chart Click here to download (22KB GIF, 1200x800 pixels). If you find that your focus is sharp when you are zoomed in but soft when zoomed out,. As for the OP, I confess I had no idea such a chart existed, but one of these days will want to try it out - just to test the steadiness of my hand.! JohnnyRebel Senior member.
Hi,I did some testing on my Tamron 28-75 and Canon 50 1.5 to see the focus accuracy using focus chart below:It is mentioned that we need to aim the camera at 45 degress to the chart. I used tripod and try to aim 45 degress, however, I am not 100% sure if it is exactly 45degress or it might be slightly less or more than 45 degress, and results varies in sharpness/ focus accuracy (most are front focus slightly, one or two are back focus). My question is, would it affect the result on 'focus accuracy' (backfocus, front focus or 'just right/ perfect') if I miss ie. 48 degress or 42 degress when testing it?
Focus Chart Nursing
Both of them I was testing were wide open at f2.8 (tamron) and f1.8 (canon). Please advise. The 45 degree angle between the chart and the focal plane of the sensor does not need to be precise. You could be off by 10 degress without significant effect to your conclusions.
The only error you would get if your angle is different from 45 is in the amount of front or back focus you can read on the sides, but it would never show front focus if you don't have it. It is more important to make sure that the horizontal lines in the chart are parallel to the focal plane. If they are not, you could observe front focus on one side and back focus on the opposite side, even if focus was accurate.downunder23wrote:Hi,I did some testing on my Tamron 28-75 and Canon 50 1.5 to see the focus accuracy using focus chart below:It is mentioned that we need to aim the camera at 45 degress to the chart. I used tripod and try to aim 45 degress, however, I am not 100% sure if it is exactly 45degress or it might be slightly less or more than 45 degress, and results varies in sharpness/ focus accuracy (most are front focus slightly, one or two are back focus). My question is, would it affect the result on 'focus accuracy' (backfocus, front focus or 'just right/ perfect') if I miss ie. 48 degress or 42 degress when testing it?
Both of them I was testing were wide open at f2.8 (tamron) and f1.8 (canon). Please advise. I've had the best results using this test chart (Target).
It is much easier to use to IMO. Set the target in good light (Best you can) and make sure to turn off IS if you have it and use manual mode to ensure the settings do not change between shots. I use a tripod and timer delay to trigger.
Aim at the center and adjust forward backward until the '0' is most in focus. A bit tedious, but worth the effort if you do it right. Be sure to use the heaviest paper you have and highest quality printing opion your printer allows.KevinIMG. Could you have a description somewhere in English on how to use it?And is this the actual size of the image? Or is there any other version?Thanks for the info.mevbowrote:I've had the best results using this test chart (Target).
Printable Focus Chart
It is much easier to use to IMO. Set the target in good light (Best you can) and make sure to turn off IS if you have it and use manual mode to ensure the settings do not change between shots. I use a tripod and timer delay to trigger. Aim at the center and adjust forward backward until the '0' is most in focus. A bit tedious, but worth the effort if you do it right. Be sure to use the heaviest paper you have and highest quality printing opion your printer allows.KevinIMG. Just a note:Canon does not recommend using angled targets (at least in regards to AF Micro Adjust) - the reason is that the target line actually (depending on the magnification) represents a 'range of distances', i.e.
Back Focus Chart For Sony Ex3
When angled backward the focus line lower edge is closer to you than the upper edge.Further Canon does nor recommend performing these tests (on normal lenses) at less than 50 X focal length (i.e. 50mm x 50 = 2,5m for the 50mm 1F8) - due to potential influence (focus shift) of uncorrected spherical aberration at close distances. hans. There are a number of test charts, and some of them can give really confusing results, particularly those with a lot of horizontal ruler lines. There is no way to know or control exactly which line the camera is focusing on, since the AF sensor is larger than the red box you see in the viewfinder.The one I have used that works most reliably is found here:The chart is available in different versions, and I use the one with the lightest possible area surrounding the horizontal focus line.
I did find my camera AF locking on to the wrong line if I used a chart with darker printing surrounding the center line.Jefrey has a very good write up on how to use it as well. The angle of tilt is not really critical, but it should be absolutely perpendicular so left and right do not show different focus when, they are actually the same.