I had used 18- 25 for red free and now often rely on 36. For FA's our early- mid shots were well exposed at 75-125 and now I am starting at 150. The late shots (around 6-8 minutes) are fine around 200-300 but sometimes 300 is not bright enough. I am often using the small pupil setting. The large pupil setting seems to wash out/ lose contrast.

The filters had slight wearing on the edges so I replaced them. The flash tube was replaced as well. Neither improved exposure. We just raised the gamma setting which seems to have helped, but only slightly. Topcon support stated good exposure when using the lower flash power in the past was abnormal, and the high flash power I am using now is normal for the TRC 50EX.

The attachment is as follows ; flash power of 1st/ #1) 18, #2) 25, #3) 36, #4) 50, #5) 75 Pupil dilated to 7-8

I would love to get feedback from other Topcon users. Are these normal flash settings for you? Are there any settings in the capture program you would recommend to play with?

SInce you've ruled out the flash tube, I would concentrate on the sensor settings. Gamma adjusts the midtone brightness (along with contrast & saturation). I would try increasing the gain a little. Gain adjusts the entire tonal range, not just midtones. You may be able to get back to your previous flash settings this way, but be careful not to introduce too much noise in doing so.

What digital sensor are you using? Do you use the same sensor for both color & FA or separate backs?

We use a 50EX here with dual Redlake sensors (ES11000 for color, ES3200 for B&W). Exposure for color fundus is typically 25-36 ws with the gain set at 6. With a different sensor, the settings are often completely different.

I've attached a PDF of an article from the JOP that discusses gain, gamma & other digital settings.

We have one sensor/ back. Redlake ES 11000

I will try adjusting the gain and see if I can find a good medium. So far we have been shooting on a gain setting of 0 and gamma 0.65.

Thank- you for the PDF. The more knowledge the better! I will read over it. I will inform you next week how the adjustments worked :)

Much appreciated,

Ruth

I adjusted the settings which improved it slightly.  The components of our TRC 50 EX started to act up on us with pixellation, reduced exposure, and  loss of FA sensitivity, and signal. We ended up having to replace the Redlake, control box, and cable connections. Replacing the redlake did help slightly with exposure issues as well. The quality was not acceptable so we now have new Nikon D90 color and Stingray FA camera attachments which solved that and other progressive problems.

I am shooting color on flash settings as low as 6-12, and starting FA's at 36- 50. Quite an improvement.

Thanks again!