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What is causing this noise?

Started Apr 30, 2019 | Questions thread
OP Jeffry7 Contributing Member • Posts: 899
Re: What is causing this noise?

jvc1 wrote:

Jeffry7 wrote:

Hi folks,

Not sure if this is the right place for my question, but the camera is a 550d, so here goes.

I took a daytime shot of the moon over the weekend with a manual lens and it turned out really noisy.

800mm, ISO 100, 1/60, 100% crop

Someone I showed this to suggested it was underexposure, but the histogram looks OK.

Full image via Rawtherapee

Any ideas?

The crop looks way over exposed. What lens? Looks like a cheap mirror lens. What's the full image look like? The area of deep space should be all black, the moon should be very bright. SS looks to slow, something's wrong with the whole thing. Can you attach the full image with exif?

Hi jvc1,

It is a cheap lens, but not a mirror. It is one of these:

https://www.celestron.com/products/travel-scope-70-portable-telescope

Which is to say a cheap telescope. Behind the telescope lens I have a t-mount 2x teleconverter.

This is a daytime shot. It was taken at 8am. The background is the correct color because the sky is blue during the day. I explained it was a daytime shot in the OP. Not sure how to make it plainer.

I will try to post the full with exif, but that is around a 100mb Tiff, and DPReview seems to be choking on it.

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