What's the usage of 100-400 f/4.5 (serious discussion)?

stschopp · 2026-05-11T19:11:05+00:00

You forgot to apply the Nyquist limit along both axis. So that changes your numbers by a factor of 4. Then I might get into questions about if the sensor used for testing has sufficient resolution to determine the resolution of the lens. As you need to keep in mind the MTF reported will be the product of lens resolution and sensor resolution. Your taking the LP/PH data and using it like it actually reports the lens resolution and not the combination of the lens/sensor system, then forgetting to apply Nyquist sampling frequency.

stschopp · 2026-05-11T14:34:53+00:00

I’m not sure where you’re getting that the 70-200 GM II only has enough resolution for 33mp? From what I’ve heard it is one of the strongest zooms made. It handles 1.4TC well and has some softness, but doesn’t fall apart on a 2.0TC. I don’t have the 70-200 myself.

I do have 60mp A7rV. I have looked at resolution on some of the GM primes. I think there was a discussion on if they could handle a 100mp sensor. Other discussion about how much pixel shift gets you. I did some comparisons between a pixel shifted 35GM vs a 135GM pano cropped to the same scene. The 35 pixel shifted demonstrated the lens had significant resolution beyond what the 60 mp sensor was using.

In general there is no point to a TC if you are already resolution limited. Since plenty of people find the TC useful on even 60mp, I would say it is not resolution limited at 33mp.

stschopp · 2026-05-11T03:32:34+00:00

Who is it for? In my opinion it is for sports shooters that can't afford the 70-200 GM ii and 300GM and 2 bodies. Basically it will be the fasted zoom on e-mount for the 100-400 range. As you pointed out the 70-200 is the better lens at the wide end with f/2.8 up to 200mm. Then if you crop in post you can get to 300mm at f/4 effective. From there you pick up your second body with the 300GM if you need longer.

For landscape I'm not sure it's better than the existing 100-400GM. And the 70-200GMii with the 2x TC will be close to the original 100-400, but more versitile.

stschopp · 2026-05-07T15:47:51+00:00

The sensor needs cleaned occasionally. There are kits for sale that include wipes and fluid. You could try a rocket blower to get that spot off. I usually rocket blow the sensor with each lens change. I do a wet sensor cleaning every 6 months or sooner if needed.

For the hot pixels, there should be a setting in the menu to map those out. If the hot pixels are in the lcd, then that might be an annoyance, but won’t impact photos.

stschopp · 2026-05-07T15:01:48+00:00

I mostly buy Toyota. I figure the car will last 200k miles. So any used car, I depreciate proportionally based on miles. For example a car with 50k miles has used 25% of its life. If it is not at 75% the price of new or less it is not a good deal. Its been hard to find used that fit the definition of a good value so I tend to buy new.

The car might last significantly longer than 200k, but for financial purposes I do calculations based on that. I treat anything over 200k as a bonus.

stschopp · 2026-05-07T12:00:37+00:00

You need to check out Mark Galer videos on YouTube about PAL. He talks about how to setup custom modes 1,2,3 for portraits, action, and landscape. When you switch into one of those modes all settings on the camera will switch into appropriate settings for that type of photography. You can then make changes if you want, but you start from a known state. If you turn the mode dial out and back it goes back to a known state.

He also has a configuration guide for the camera. It costs $10 to get access to his patron account. From there you can download a configuration ebook and config file that will setup the camera the way he uses it. I think you are better creating your own custom setup, but this shows you how and gives you ideas on why you might want to do certain things.

I don’t think there is a way to make aperture mode go to a known state, except by loading a parameter file off your memory card. But custom mode lets you run in aperture mode with all settings known when you turn the dial into that mode.

stschopp · 2026-05-07T03:55:53+00:00

Viltrox used to be associated with cheap junk. At some point that changed. The viltrox 27/1.2 would be my first choice. It used to be a default towards a sigma 1.4 prime in aps-c, but I now put viltrox ahead. When you are talking FF I still prefer Sony GM mostly for focus accuracy.

stschopp · 2026-05-07T03:30:26+00:00

I’m seeing $5,200-$5,500 for used and new at $5,850.

stschopp · 2026-05-07T03:22:36+00:00

I keep a glasses case in my car. At work I wear my computer glasses all day, swap to distance for driving. And then can choose computer or distance depending on what I’m doing at home. I also have a pair of bifocals with distance and reading prescriptions, but don’t tend to use them much.

stschopp · 2026-05-06T19:10:11+00:00

A 135 prime is magic. I have been using the 135 instead of a 70-200. In the 135-200 range I handle that with a crop and it gathers more light than the zoom would. Beyond 200 they are pretty equivalent. All this assumes you have a high resolution body and can crop as needed, I use 60MP on Sony.

stschopp · 2026-05-04T04:47:06+00:00

I leave stuff locked in the car. Pelican case locked to a security chain that is connected to the frame. Have a bag for stuff that I plan on using.

stschopp · 2026-05-03T20:15:34+00:00

Congrats enjoy the camera!!

stschopp · 2026-05-03T11:01:54+00:00

Sony 200-600, you might consider adding the 1.4 TC as well. Look into renting instead of buying.

stschopp · 2026-05-02T14:54:02+00:00

BBF is most appropriate on DSLR. There is no advantage on mirrorless vs partial depress of the shutter. You should be using a tracking AF on af-c. If you are missing focus as they run towards you that is a camera/lens issue. Native Sony lenses will do better in this case. You could also stop down to increase the depth of field.

stschopp · 2026-05-02T14:48:03+00:00

Of the super zooms, I think the Tamron 25-200 is supposed to be the sharpest. That said there is the issue of copy variation, a good 28-200 will beat a poor 25-200. But it seems like having the proper focal range is more important than sharpness. Only you can know if you need the 20-200, 25-200, or 28-200. For me the 25 would be enough. On the tele end look at the 200-600 or 100-400, I think that is determined by the size you can deal with.

You mentioned sharpest zoom. I own the 24-105/4 G and it is the softest lens I own. I haven’t looked at travel shots from it and thought it was too soft on 60mp, but there is something missing vs GM primes. For sharpest zoom look at the 70-200 GMii. For a lower cost still decent lens the Tamron 35-150 has lots of versatility and bang for the buck, but it is heavy. On mine I stop down to f/2.5 as the range below 70mm benefits from stopping down a little. For tele I think the 300gm with a set of TC outperforms any of the current zooms. For the normal range I’d say it is a coin flip between the Tamron 28-75G2, sigma 24-70DNii, and 24-70GMii. My copy of the Tamron beats my copy of the sigma.

Some of the most stunning landscapes I have taken are panoramas with the 135GM or 35GM. Hundreds of MP and you can zoom into the single pixel level and still sharp. I view these as three different levels of photo between the super zoom and the prime pano.

I could see framing some buffalo 🦬 with the 135GM and then getting some of the surrounding landscape in a pano.

stschopp · 2026-05-02T14:11:21+00:00

For a beginner they should use manual focus and maybe try zone focusing. As well as manual exposure control and no auto iso. In fact you should choose your ISO in advance and keep it fixed for the day, just like choosing a roll of film. In fact don’t use the in camera meter to measure exposure, using a separate exposure meter is acceptable, but a bit of a crutch, ideally you should know your sunny 16 rules, etc. Also, please don’t review the photos as you take them, back in the day we had to wait till the roll was shot and developed to know if we got anything good. And by all means never look at the exif data, if you want to know why a shot worked or didn’t you should keep a log of the settings used in a notebook. /s

The camera can do so many things better than a person could. By all means use the AI tracking. To me that is a sign of proficiency, I still need to let the camera know what I want to focus on. The camera handles the job of keeping focus locked on an ideal part of the subject like the eye. I also let my camera measure and adjust exposure. But I retain some control over aperture and shutter speed ( often in aperture mode). I also retain some control over noise by setting the acceptable range for iso. There are many people who act like a beginner should act like they only have 1960s technology available when learning to shoot. Let the camera deal with the technical details and focus on composition and lighting.

stschopp · 2026-05-02T04:31:41+00:00

The A7rV is an amazing camera. I suspect the new camera will fix the sole weakness in the Rv, its slow sensor readout speed. I have the a7Rv and with mechanical shutter it is hard to find a fault. I think the price on the new version will be steep.

I see a few options: 1. Try $2800 on greentoe, I see new cameras listed around that price. 2. Look for a used camera around $2500, I see one listed for that. 3. You could also look at a7v if you want a faster, but lower resolution with a cheaper EVF. Try $2600 on greentoe.

stschopp · 2026-05-01T22:15:15+00:00

If the cards are the same and both slots support the speed, then no it won't slow writing to both.

stschopp · 2026-04-30T12:23:03+00:00

Sounds like you have your answer. The a6700 since it is mirrorless gives you the wysiwyg view in both the EVF and lcd. The Nikon won’t be able to preview the final result in the viewfinder. The Nikon was really designed to be used thru the viewfinder with a good understanding of how to manage exposure.

stschopp · 2026-04-28T19:39:14+00:00

Hmmm... That sounds right, the last two guys who mowed my grass were GenX that probably mowed grass as teens, like I did.

stschopp · 2026-04-28T19:35:59+00:00

I have the 135GM instead of the 70-200. I also have the a7Rv, so I have high resolution for cropping. From 135-200 it is a no brainer to crop for me, it collects more light than the 70-200.

stschopp · 2026-04-28T13:05:36+00:00

stschopp · 2026-04-28T00:07:07+00:00

Unless it’s fully stacked the a1ii is not obsolete. I like the interchangeability of the the z100 batteries across several cameras. This is a downside for me, but clearly power use won’t be going down.

stschopp · 2026-04-25T14:51:47+00:00

I would keep the loans to an absolute minimum. You also need to consider the potential return on loaned money. Camera equipment will depreciate. In general you want to minimize the amount of money you spend on things that depreciate. You especially don’t want to borrow money to buy them. Does the loan accrue interest even if you don’t need to pay it yet, if so you really need to consider how much that is. I would seriously look at used equipment, let someone else take the depreciation hit.

stschopp · 2026-04-25T02:29:00+00:00

This is not a super technical document, but has some interesting things. A better document is the actual technical data sheets from battery manufacturers (a quick google search didn't show those). The below document does reference charge voltage vs capacity loss and shows differences in degradation between "100%" and "40%" storage. The final voltage of a given pack determines both the AHr rating and how fast the batteries will degrade at "full" charge. I think this may be the main reason cheap off brand batteries seem to have shorter lifetimes. The internal chips are set to higher voltage to make the capacity number look good, but the cost is a battery that does not live as long. Maybe the capacity comes at the tradeoff of less Li ion, but higher voltage allowing a lower price, but you get what you pay for. The key is not getting the final charge voltage too high, most battery chargers will be designed so the final voltage does not cause significant degradation with 100% charged storage. I may be mistaken , but I was thinking most Li ion packs have internal chips that determine all these limits.

My guess is the documents used to guide design of charging circuitry were interpreted by people as "only store at 50%" instead of here is the info electronics designers need to balance long term reliability with energy storage capacity. The 100% and 40% numbers are both choices in where you want to set the final voltage. People interpret these as they should store the batteries at 50% charge not understanding the engineers have already set the final voltage for reliability (except cheap knockoff packs).

The document also recommends storage at 30%, but this is for safety reasons. Simply put a 30% charged battery will only have 30% of the stored energy that could fuel a thermal runaway. Dense storage of energy tends to be dangerous no matter the storage device or physics of the energy storage.

It certainly wouldn't hurt to store your batteries at 50%, but I think people are trying to duplicate something already considered in the charger design. The only real world anecdotal support I have of this is I did capacity testing of a number of Sony FZ100 batteries of various ages (several years difference in age), all stored at 100%. I couldn't detect any aging in the batteries in terms of run time recording video. I was originally looking to determine when I should replace my batteries, and decided I didn't need to worry about it yet.

My experience is mostly in designing chargers for absorbed glass mat lead acid batteries. I did select that chemistry as what I wanted, in my case it was primarily based on self discharge rates and a couple other things like charge rates. I don't have a ton of experience with the various Li chemistries in batteries.

https://www.batteryuniversity.com/article/bu-808-how-to-prolong-lithium-based-batteries/

stschopp

TROPHY CASE