[Sudhir Shivaram]

Yes, using an EF-to-RF adapter on your Canon EOS R with the Sigma 60-600mm f/4.5-6.3 DG OS HSM Sports (EF mount) can sometimes introduce autofocus inconsistencies. The issue you’re describing—AF shifting slightly after focusing—can be due to a few key reasons:

Possible Causes of AF Issue

1. Adapter Compatibility Issues

• Canon’s official EF-EOS R adapter works well, but third-party adapters (Viltrox, Commlite, etc.) can cause minor AF issues.

• Even with Canon’s official adapter, some third-party lenses like Sigma & Tamron may behave differently from native Canon EF lenses.

2. Sigma Lens AF Algorithm Differences

• Sigma lenses (EF) were designed for DSLR phase-detect AF, while Canon EOS R mainly relies on Dual Pixel AF (DPAF).

• The translation between DSLR-style AF and mirrorless DPAF through an adapter can introduce slight focus drift at the end of AF.

• Sigma firmware may not be fully optimized for RF mount AF behavior.

3. Lens Firmware Update Needed

• Sigma frequently releases firmware updates for better Canon mirrorless compatibility.

• You may need to update your Sigma 60-600mm lens firmware via Sigma USB Dock.

4. Focus Breathing or Slight Backlash in Focus Mechanism

• Some long zoom lenses (especially super-zooms like 60-600mm) have minor focus breathing or internal backlash in focus motors.

• This can cause a tiny shift in focus when you release the button.

5. Low-Light or Low-Contrast Conditions

• AF inconsistency in low light or low-contrast scenes can be exaggerated when using an adapter.

[Sudhir Shivaram]

Go for the Sony 6700

[Sudhir Shivaram]

Yes, it has some impact, but it’s not necessarily bad.

1. Low-Light Performance – Larger pixels (D5100) collect more light per pixel, which generally means:

• Better low-light performance

• Less noise at high ISOs

• Better dynamic range

• However, Nikon’s improved sensor tech and Expeed 4 processor in D5600 compensate for this.

2. More Megapixels = More Detail

• The D5600’s 24.2 MP sensor provides more fine details compared to the 16.2 MP sensor of D5100.

• However, smaller pixels may slightly increase noise at very high ISOs.

3. Better Autofocus & Features

• D5600 has a 39-point autofocus (vs 11-point on D5100) → Better subject tracking.

• Touchscreen & Wi-Fi (SnapBridge) make it more user-friendly.

[Sudhir Shivaram]

Since no single lens covers 20mm to 200mm with a wide aperture and stabilization, you might need to go for two lenses:

1. Tamron 20-40mm f/2.8 Di III VXD (Best budget wide zoom)

• ✅ Fast f/2.8 aperture

• ✅ Compact & lightweight

• ✅ Great for landscapes & low-light

• ❌ No image stabilization, but Sony IBIS helps

2. Tamron 50-400mm f/4.5-6.3 Di III VC VXD (Best budget telephoto zoom)

• ✅ Covers 50mm to 400mm (can crop for more reach)

• ✅ Has Vibration Compensation (VC)

• ✅ Sharp images and great autofocus

• ❌ No f/2.8 aperture (but excellent reach & stabilization)

These two lenses combined will almost cover your desired range.

Other Possible Choices

1. Sony 24-105mm f/4 G OSS (For a balance of range, stabilization, and quality)

• ✅ Optical SteadyShot (OSS)

• ✅ Sharp, versatile, and reliable

• ❌ f/4 is not as wide as f/2.8

• ❌ Doesn’t reach 200mm

2. Sigma 60-600mm f/4.5-6.3 DG DN OS Sports (If you want crazy reach)

• ✅ Optical Stabilization (OS)

• ✅ Super versatile zoom range

• ❌ Heavy and large

[Sudhir Shivaram]

The camera / lens you have is a basic entry level one. Not sure what your expectations from them are. Also the issue you say is very difficult to resolve without knowing the lightig condition, what subject are you trying to shoot, how far are they etc etc. Can you please post a sample image of what you are trying to shoot?
Just to set the expectation, 1500D and 55-250 lens combination is a entry level model and cannot expected to be super fast.

[Sudhir Shivaram]

You can refer the Z9 guide for this as the menu system is the same across all these mirrorless models with only a few variations with the features and options.

[Sudhir Shivaram]

Youc an refer the D750 guide for this. Good thing about all these brands are that the Menu system is almost the same across all models. Also, please do follow the learning path document for better learning.

[Sudhir Shivaram]

Go for Lightroom Classic. There are offers in creative cloud for the Photographers Package. Go for that. You get both photoshop and LRC in that.

[Sudhir Shivaram]

Camera purely depends on your budget. So best option is to check the Sony, Canon and Nikon website and see what cameras with lens come within your budget. And then decide.
There are no bad cameras. It depends on your purpose. Check for the specs and if it matches your requirement, that’s enough.

[Sudhir Shivaram]

Please check http://www.ssp.photo/best

ssp.photo

Best Camera Lens For Photography - Sudhir Shivaram Photography

Best Camera Lens For Photography - Sudhir Shivaram Photography

[Sudhir Shivaram]

You can avoid that now. The Denoise of photoshop is quite powerful.

[Sudhir Shivaram]

A warm welcome to you on the platform. Please ensure to follow the photography learning path document if you are keen to learn and improve:
https://learn.sudhirshivaramphotography.com/groups/all-in-one-pack-support/forum/discussion/photography-learning-path-for-all-in-one-pack-course-subscribers/

[Sudhir Shivaram]

A lot of ethical aspects are involved in nest photography and hence it is not encouraged.

[Sudhir Shivaram]

3rd week may still be good. Once the heat builds up, birds will start leaving.

[Sudhir Shivaram]

Not sure what options in mirrorless you are getting for camera below 50K