little jim

The shadow is due to vignetting from the central baffle of the folded optics of your mak.  The image circle won't cover a full frame sensor.  I see the same with my 100/1500 mak on the Sony A7 sensor.

Being an astro guy, I went directly to the coma and astigmatism part of the lenstip review of the Sony 50/1.2 GM and was underwhelmed...  until I searched out the corresponding result for Canon's ...

It seems you're migrating from a 2-lens 18mm/85mm kit to a 3-lens kit, from a "non-astro photography" point of view.  But since 90% of your photography is astro, this obviously must be a major ...

I think this is rolling shutter--i.e a mismatch between EFCS and rear curtain mechanical shutter.  Above a certain threshold in faster shutter speeds, you need to turn off EFCS and rely on the ...

Camera trackers are limited in payload capacity, usually <10 lbs.  Equatorial mounts are recommended for telescopes and larger telephotos.  The EQM-35 is rated at 20 lbs. The AVX is rated at 30 lbs. ...

I've long admired the output from your Tak 106/530 F5 Astrograph.  Also, kudos to your choice of the ASI2600 camera.  Definitely a winning combination. In your posts, I don't recall your mentioning ...

As a *professional* bird/nature photographer, you haven't convinced me that the Canon R6 isn't your cheapest upgrade path, adapting your existing EF glass (particularly your 500/F4) to the RF ...

...courtesy of Chris Stephenson, RASC St. John's Centre, St. John's NL, Canada. Stellarium output courtesy of Chris Stephenson, RASC St. John's Centre. Edit:  Here's a single raw frame, boosted by ...

After weeks/months of cloudy skies, the sky cleared for a few hours with fantastic seeing at sunset on 20 Dec 2020. The following shot of the Jupiter-Saturn conjunction was captured on a 1970s ...

There's no doubt the Redcat51 (250mm/F4.9) would yield fantastic images, even with your full-frame Nikons (most refractors perform best with APSC cameras, FF image circles are hard). But, given ...

Pairing the unmodified D850 with the WO GT71 should deliver awesome shots!  Use a solid mount! LJ

I've uploaded my most recent astro efforts with M16/M17 using a vintage 500mm lens and modified A7 to my gallery.  Calibrated with ~30 bias and ~30 flats (no darks) and stacked in PI, colour ...

I shoot fast telephotos (300/2.8 and 500/4.5) with the Sony A7R3, so I've had to address all the issues you are confronting with your M31 shot. First, there's a lot to like about the detail the ...

I don't know what lenses/telescopes will be paired with your D850, or what type of AP you plan to do (there's a difference between UWA and superzooms, lenses versus telescopes).  I shoot DSOs with ...

I agree with Alen K above that reducing "noise" is the whole point of increasing exposures.  However, a perfect camera with zero noise necessarily suffers from the problem of random *signal* (aka ...

Hello Dan: First, great shots! I'm inspired, given I'm at latitude 47deg and find these targets too low most of the year. I wanted to add a comment regarding what you call "reflections". I have ...